Topic: Electrics FAQ

[Harry]

My bike is not charging!

Glenn wrote: Check the wiring diagrams and disconnect and clean all of the connections between the alternator and the battery.  Clean up the alternator rotor and brushes.  Put it all back together.  Connect a multimeter to the battery terminals, start the bike, and check the voltage readings against this chart:  http://sohc4.us/?q=node/62

You may find the procedure here helpful: http://www.electrexusa.com/Images/fault_finding.pdf

--Glenn

PS: searching the greenspun archives using the words 'not charging' would have led you to all of these tips.   

[Harry]

cb750_chris: This is how a trained Honda mechanic would service your bike if you took it in and claimed it had a charging problem.  Rather I should say trained and interested in doing the job right on an old bike. 

Three phase charging system inspection and maintenance for all pre 79 SHOC4 motorcycles. 


I.   Initial inspection.
A.   Charging system fuse check
1.   If open replace.
2.   If shorts again search for short circuit.
 
II.   Full load test.  (Determines battery condition).
A.   Turn ignition and high beam on while bike is not running. 
B.   Test battery voltage. 
C.   Voltage bellow 10.5V means battery needs service. 

III.   Charging the battery. 
A.   If specific gravity of any cell is less than 1.230 battery has low charge.
B.   If sediments in battery are touching bottom of any plates replace the battery. 
C.   If specific gravity varies more than .050 then replace battery. 
D.   If fluid level is low add distilled water only.  Don’t add too much as level may rise even more while charging. 
E.   Charge the batter at no more than 10 percent of its amp hour rating. 
F.   If battery temp. is more than 113 degrees F allow it to cool then resume charging. 
G.   If specific gravity of any cell will not charge above 1.230 then replace the battery. 
H.   Put the fully charge battery back in the bike and do the full load test again.  A running RPM test cannot be done unless you have a fully charged battery.  If the voltage is above 12V then you can do the RPM test.
I.   Start the engine and lock the throttle when the RPM is above 4000.  If the voltage is between 14V and 15V the system is fine and the battery was to blame.  If not you have more work to do. 

IV.   If @ 4000 RPM the voltage was bellow 14V…
A.   Check for problems. 
1.   Corroded, loose, or mismatched wires.  I.e. orange and green wire plugged in to each other. 
2.   Modified or non-stock systems.
3.   Visibly damaged wire insulation.
B.   Do a system analysis resistance test. 
*.  NOTE 0 resistance = good wire. 
*.  NOTE infinite resistance while grounded to frame = good insulation.  Coils will automatically have resistance.



C.   Resistance testing of regulator wires. 
1.   While the bike is not running disconnect (-) battery lead and Black regulator wire.  Check for 0 resistance between (-) battery wire and Black regulator wire.
2.   Disconnect all regulator leads. 
a.   Test for resistance between I and F poles.  0 resistance is good.  If greater than 0 clean the regulator points. 
b.   Test for resistance between the white wire and ground.  Resistance between 4 and 8 ohms means the field coil is good.
   
V.   Testing the stator yellow leads. 
A.   Test wires 1 and 2, 1 and 3, 3 and 2 for ohm readings.  Less than 1 ohm means the circuit is good.  Greater than 1 ohm means poor connection.  Infinite resistance means that the coil has an open circuit or possibly a bad lead. 
B.   NOTE.  For GL1000 you need to disconnect/remove the permanent magnet rotor before continuing.  Set tester to insulation resistance and calibrate it to 0 to perform a wire insulation test on the stator.  Ground the negative test lead and touch the other lead to each of the three stator wires.  If the resistance is infinite then the coil is ok.  If not then the coil is shorted to ground. 
C.   Test the three stator wires in the harness of the motorcycle.  First disconnect the rectifier.  Set the tester to resistance.  0 resistance means all three wires are fine.  Greater than 0 means the wire is bad. 
D.   Check the wires for bad insulation.  Connect the black tester lead to ground.  Each wire should have infinite resistance.  Greater than infinite resistance means the wire has bad insulation. 

VI.   Check the five leads on the rectifier. 
A.   To perform a forward bias test first connect the red tester lead to the green ground lead. 
B.   With the black tester lead test all three yellow wires. 
C.   Resistance must fall between 5 and 40 ohms. 
D.   To perform a reverse bias test connect the black tester lead to the green ground lead. 
E.   With the red tester lead test all three yellow wire. 
F.   Resistance must be greater than 2000 ohms. 
G.   Connect the black tester wire to the red and white rectifier lead. 
H.   With the red test lead test all three yellow wires. 
I.   All three must have between 5 and 40 ohms. 
J.   Connect the red test wire to the red and white rectifier lead. 
K.   Test all three yellow wires with the black tester lead. 
L.   Resistance must be greater than 2000 ohms. 

VII.   Testing the harness plugs and leads. 
A.   Test each of the plug wires in the circuit for o resistance. 
B.   While the battery and rectifier are disconnected test the red and white harness rectifier wire to the (+) battery lead for 0 resistance. 

VIII.   Regulator bench test. 
A.   Remove regulator cover. 
B.   First check the core gap to be sure it is between .6 and 1mm. 
C.   Next check the points gap to be sure it is between .3 and .6mm.
D.   Clean the points with contact cleaner. 
E.   Note the 350F points gap is not adjustable. 
F.   Test the regulator leads by first placing paper on both sides of the points contacts. 
G.   Test resistance between I and F, then I and E terminals.  Check you manual for model specific resistance readings. 
H.   Test for 0 resistance at regulator points connections.
I.    While the points contact is in the upper position test between I and F. 
J.   While in the lower position test between F and E. 
K.   Note.  Do not file the points or they will quickly pit when used again.
 
IX.   Perform RPM test again.  Be sure all components meet specks before going forward from here. 
A.   Reconnect all components but leave the regulator cover off. 
B.   Start the bike and lock the throttle at 4000 RPM. 
C.   The voltage should read between 14V and 15V. 
D.   If voltage is low unlock the adjuster screw nut and turn the IN. NOTE do not run the screw into the coil winding or short the screw to something else with the screwdriver.   
E.   If voltage is high adjust the screw OUT. 
F.   For the 350F bend the arm up for and increase in voltage or down to decrease. 
G.   Replace the cover and test the voltage again as the cover can have an affect on the field of the coil. 
H.   GO FOR A RIDE!

[SteveD CB500F]

www.rattlebars.com/mtz/hornrelay.html (thanks gkw120649 )

[SteveD CB500F]

Go here:

http://www.motorcycleproject.com/motorcycle/text/cows-blue.html

[SteveD CB500F]

Bodi wrote:

The first thing to do is get a wiring diagram, the Clymer/Haynes ones are worse than useless because they leave important things out. Example - the headlight circuit does not show that the power goes through the starter button; you could look for hours in total confusion trying to understand why you have no headlight power if you believe the diagram is complete. The Honda shop manual or owners booklet wiring diagram is complete - every wire and connector is shown - but it's a bit hard to understand until you get used to it.

A good start is to remove the tank and headlight, the side covers, and the left engine cover. This should expose all the main wiring connections.
 
The bullet connectors are pretty nice, they're small and carry the current involved easily when clean and new. The sex is useful too, power is always on a female connector and the load or return is always on a male - the male can easily contact metal and that would mean at least a blown fuse if it was a power wire.
But... after 20 or 30 years the bullets are no longer clean or new. Once corroded and loose they get hot, and can melt the plastic parts. That's why you find the twist-on yellow things, the bullet self destructed and new ones are basically impossible to find - especially multi-tap females - and the yellow twisties do the job.
To prevent meltdown clean the male ends with some steel wool or a scotchbrite pad and the females with a q-tip or a twist of scotchbrite. You can flush the female end out with contact cleaner or brake cleaner (test the brake cleaner to ensure it does not dissolve anything, some formulas do). Smear some dielectric grease around the male end and push it in. If the female is loose and there's no resistance or snap, tighten it GENTLY with pliers.
(do not read the above paragraph aloud in public)

Connect colour-to-colour. The wires can get dirty and all look brownish black but a wipe with varsol or such will bring the colour back.
The muliticircuit connectors on the electrical panel can be cleaned in a similar fashion and the females tightened a bit with needle nose pliers.

Once the wiring harness connections are all good, you can look for problems effectively; many mysterious electrical woes just disappear.

1) the magnetic switch (solenoid) doesn't affect any lights, it just activates the starter motor.
2) The starter motor does not affect the lights, ignition, anything. It is wired directly to the battery through the solenoid switch.
3) The oil and neutral switches are in the engine. Hammering the solenoid to fix a problem suggests trouble in the electrical panel, the bottom plug goes to the engine and has the alternator and oil/neutral switch wires. There's a control box that keeps you from energizing the starter unless the transmission is in neutral or the clutch is pulled in, that may be a problem too; it's on the electrical panel I think. Disconnect and remove the whole panel, check inside for any loose or broken wires or any evidence of overheating.

- The start button shuts off the headlight while starting, this is a common failure point as the switch guts tend to melt when they get corroded and overheat from the (constant) headlight current. Many headlight woes trace back to the starter switch.
- The kill switch is ONLY in the ignition coil circuit and it has no effect on lighting, starter, horn, etc.

[Harry]

Basically, no, although for a bare bones racer without lights etc. a capicitator may work.

Lloyd (TwoTired) provided the following information:
The CB550 alternator will not make any power unless there is a magnetic field for the stator. There is no permanent magnet in the alternator, so...
This magnetic field is created by the field coil being energized from the battery. Once the field is excited and the engine is spinning, it makes far more power than it uses from the battery.  But, without the magnetic field, to get the process going, it makes no power. The coils need power to make plugs ignite the fuel.

To operate [...] without a battery would require adaptation of a permanent magnet into the alternator where the field coil usually resides.  And, it will have to make way more power than the current design at idle to run all the lighting and the coils.

Lloyd (TwoTired) provided this additional information:
The SOHC4 alternators work by using magnetism created by an electromagnet (the field coil) that only behaves as a magnet when it is provided electricity needed to make a magnetic field.
Our field coils draw about 1.7 amps whenever the alternator is powered by enabling the key switch. (.7 amps if an installed battery is above 14.5V... not likely without the engine turning).

Each ignition coil draws 2.4 amps (5 ohm primaries) whenever its associated point contact is closed.  There are two of them.  Also, note that spark voltage diminishes with input voltage loss.  When supply voltage falls below about 9 V, spark gap arcs are ify, at best.  So, if you can eliminate any additional lighting loads, whenever you turn on the ignition, 4.1 amps at no lower than 9V are needed before the engine or alternator rotor is even turning.  If not a battery, where will this current flow come from and how long?

Not the alternator.
It should be obvious that even a powered alternator will make no power output unless it is spinning.  I've not seen or measured a power output vs, RPM chart.  However, I do note that with lighting circuits enabled, the bike is unable to overcome the system loads and charge the battery, which is draining, at idle speeds of 1000 RPM.

As I understand it, the Bat Pac is simply a capacitor bank.  To my knowledge, a perfect capacitor has yet to created.  They all have series resistance and leakage resistance due to the materials they are created from and their physical properties.  What this means is that they will NOT hold a charge indefinately.  Nor will they give up their stored charge without some loss.  This later property is probably not important for this application, though.  But, the leakage is.  More on this later.

Also, since our alternators can only make power when supplied some power.  The Bat-Pac will have to be precharged to have any hope of starting the bike.  And, there will be a very limited amount of time that the capacitor will have enough charge to start the bike.  It's going to be a race between ignition on and kick start.  And, if the bike has been sitting awhile, forget it, without some external power source.

So, when you kick start the bike, you're going to have to kick it to about 1500 RPM in order to keep the Bat-Pac charged up to a level that will continue to fire the ignition coils and spark plugs.

Capacitor size.
Let's say we start with a fully charged capacitor at an optomistic14 V.  We can use it until it drains to 9V, or about 36% of its total capacity.  This is about one half of a standard capacitor charge or discharge rate. So, we must double the result of the standard 63% formula of  T / R = C, where T is time in seconds.  R is the Resitance of the circuit in ohms and C is the Capacitance in farads.

If we assume 5 seconds between key on to kick start  Then a 0.834 FARAD (834,000 microfarads) capacitor is needed that is also able to withstand, say 20 V without breakdown.

A not very thorough search, finds that Digikey has some Panasonic Electrolyic caps in 100,000 microfarads.  They are $13.36 each and eight of them ought to do it. They are also 40 D x 80 L in size (mm).  These can be wired together in a block about 3x3x6.5 inches.

It's up to you whether this is more attractive on your bike than a battery.  However, I couldn't find a leakage spec.  So, I can't calculate how long they will stay charged after you turn off the running bike.

On bikes with permanent magnet type alternators or generators, each time you kick the bike the capacitor gets recharged.  As long as the power generated from the kick is greater than the draw for the ignition, the bike will start and run.  On such bikes, the capacitor requirement is far less than calculated above.  Probably one or two caps is all you'd need.  Or, a few more smaller, cheaper ones.


And a comment by Bistromath:
There are people out there selling "Battery Eliminators", though, which are just large capacitors to achieve the same effect.

[SteveD CB500F]

Honda sent this out in 1971 to inform everyone about their "new" 3 phase system. It may help answer some of the questions that keep coming up.

Download the 3 Phase Charging Bulletion (6 pages)

Thanks to Bryan Jones.

[SteveD CB500F]

I've often wondered why we advise people to use dielectric grease rather than conductive grease for the wiring..

So I Googled it and here's the answer:

Dielectric vs. Conductive Grease to Protect Connectors and Grounds.

[Query:] You have repeatedly recommended the application of dielectric grease to underhood wire connections. Isn't the insulating property of such grease counter to the goal of IMPROVING the integrity of electrical connections? I would think that a conductive paste (such as Eastwood's Kopr-Shield) would be better. The only potential downside I can think of is that sloppy application could cause short circuits, but care and common sense should preclude this.

[Response:] This is a good question and one that I have received several times. Yes, it is true that the dielectric grease is non-conductive. However, in the context of connections that carry voltages larger than 1 volt, the grease will not result in a bad connection. The male and female connectors will wipe enough of the grease off at the mating surface so that the electricity will flow just fine. The important part is that there is no chance of the grease creating a conductive path between adjacent terminals in a multi-terminal connector. The main purpose of the grease is to seal the terminals against oxidation which creates a high resistance barrier and moisture and dirt which can result in shorts and ground paths.

[SteveD CB500F]

Thanks to Jonesy for this:

[SteveD CB500F]

More from Jonesy:

(I put this together after a few questions about the wiring in these bikes. Some suggested this be put in the FAQ. Hope this is helpful.)

Here’s a general wire guide for the 70’s Honda SOHC/4’s. Some of this may be different for the 650 (I’m mostly familiar with the 350, 400, 500/550 and 750) or bikes factory-equipped with electronic ignition. Consult your manual for specifics.

Main Color/Tracer Stripe Color- Description (Approximate Path, if Applicable)

All Circuits
Red- Constant Hot From Battery (Battery Terminal-Main Fuse-Key Switch)
Black- Switched Power Supply Buss (Throughout motorcycle)
Green- Ground (Throughout motorcycle)

Lighting
Brown- Tail Light Power (Main Switch-Tail Light)
Brown/White- Instrumentation Backlighting (Lighting Switch-Instruments)
Orange- Left Turn Signals (Turn Signal Switch-Front/Rear Signals)
Orange/White- Left Front Marker (Light Switch-Marker Lamp)
Light Blue- Right Turn Signals (Turn Signal Switch-Front/Rear Signals)
Light Blue/White- Right Front Marker (Light Switch-Marker Lamp)
Gray- Pulsing Power for Signals (Flasher Relay-Turn Signal Switch)
Blue- High Beam Power (Hi/Lo Switch-Headlamp/Indicator Lamp)
White- Low Beam Power (Hi/Lo Switch-Headlamp)
Brown/Red- Fused Headlamp Power (Fuse Box-Hi/Lo Switch)

Ignition
Black/White- Coil Power Supply (Cutoff Switch-Coils)
Yellow- Breaker Signal, Cylinders 2&3 (Right Points-2&3 Coil)
Blue- Breaker Signal, Cylinders 1&4 (Left Points-1&4 Coil)

Starting/Safety/Monitoring
Blue/Red- Oil Pressure Signal (Oil Pressure Switch-Indicator Lamp)
Red/Green- Neutral Switch Signal (Neutral Switch-Indicator Lamp-Safety Unit)
Green/Red- Clutch Switch (Safety Unit-Clutch Switch-Starter Button)
Green/White- Horn (Horn Button-Horn)
Yellow/Red- Solenoid Signal (Starter Button-Solenoid/Safety Unit)
Green/Yellow- Brake Light Power (Front Brake Switch/Rear Brake Switch-Brake Light)
Brown/Blue- Turn Signal Pickup (Turn Signal Beeper-Turn Signal Switch)

Charging (3-Phase External Excitation Systems)
Yellow- Stator Coil Output (Stator-Rectifier)
White- Field Coil Supply (Field Coil-Voltage Regulator)
Red/White- Positive Rectifier Output (Rectifier-Battery)

**NOTE- I pieced this together from referring to wiring diagrams I have. This is meant as a general guide and will vary between models/years. If anyone spots an error or omission, please post it and I will correct it. Thanks**

A few more thoughts that may help people:

Another learning I found useful in troubleshooting various circuits was knowing which sides of the circuits are impacted by switches, etc. Typically, most circuits on these bikes can be thought of as having 2 "sides"- a "hot" side (power from the main buss activated by the key switch), and a ground side. For example, the lighting on these bikes (head, tail, gauge, running and turn) is all controlled by a switch (or switches) on the hot side of the circuit, while the ground side of the circuit is always complete.

Basic Circuits controlled (switched) on the HOT side of the circuit:
-Headlight (Both Hi and Lo Beam)
-Tail Light
-Brake Light
-Turn Signals
-Marker Lamps (if equipped)
-Starter Motor (heavy-gage wiring switched by the solenoid)
(Note: while they don't break circuits under normal circumstances, the fuse(s) are all located on the hot sides of their respective circuits.)

Basic Circuits controlled on the GROUND side:
-Neutral Light
-Oil Pressure Light
-Starter Solenoid
-Horn
-Starter Safety Unit (As best I can tell, all sensors are on the ground side)

Special Case: Ignition
Under normal operation, the ignition coils are activated by the breaker points, which are on the ground side of the coil circuits, as the coils are fed constant battery power while the points interrupt the ground side. However, the emergency cutoff switch is located on the hot side of the circuit, coming into play by cutting the battery power to the coils.

And, That Age-Old Question...
...Does it matter which order I connect the yellow wires coming from the alternator to the rectifier? No. There is alternating current being carried by these wires and the diodes in the rectifier take care of sorting out the positive charges from the negative ones.

[Bob Wessner]

Submitted by: Burmashave

At some time, you will want to get acquainted with a multimeter (MM) if you are restoring an SOHC/4 (or working on any vehicle for that matter).  This FAQ should give you a basic introduction to purchasing and using a multimeter.

What Is a Multimeter?
If you're not quite sure what a multimeter is, Wikipedia has an entry for Multimeter explaining what Multimeters do and what features they offer.

Selecting a Multimeter
You can find a good multimeter for under $20.  Multimeters come in two varieties -- analog or digital.  Most MM's are digital, and most users find digital MM's easier to use, although analog meters are entirely sufficient for our purposes.  You can find multimeters in electronics shops or home improvement stores.  One feature provided by more expensive models is the ability to test amperage in ranges beyond milliamps.  A multimeter with a higher amperage range can be useful; however, testing on an SOHC/4 can be done without this feature.

How Do I Use a Multimeter
There are some good (very brief) tutorials on the web:

Electronics Club
The helpful folks at the Electronics Club provide a clear guide to using either a digital or analog MM for basic measurements.

U of Michigan Interactive Guide to MM Use
Check this out: it's an interactive MM demo!  The U of Michigan has an interactive Flash application that teaches you how to use a multimeter by allowing you to connect leads and perform tests.  It's a fun way to get acquainted with a multimeter without leaving your chair.

Basic Electrical Theory for Boaters: Multimeter - The Invaluable Tool
BoatSafe.com has a very good guide that includes hands-on examples and pictures for testing voltage, amperage and resistance.  The BoatSafe guide meshes with their Electricity 101 for Boaters, which is a brief introduction to electrical theory.

What Are Volts, Amps., etc?
For those so inclined, there are also a few guides that quickly explain the theory behind the measurements.  A brief understanding of electrical concepts often helps when troubleshooting components more complex than a bulb or switch.

Electricity 101 for Boaters
As mentioned above, BoatSafe.com has a brief guide to electrical theory.  Their guide uses the Hydraulic Analogy that is often made between basic electrical principles and the movement of water through pipes.

4HV.org: Basic Electrical Theory
4HV.org has a very clear and concise guide to electrical theory. 

How Should I Troubleshoot? (see also Jonesy's Wiring Guide and Bodi's Electrical Fault Finding in this FAQ)
Troubleshooting electronics may seem like voodoo at first; however, it is something that can be learned the same way mechanical troubleshooting is picked up.  I am by no means an electronics expert; however, here are some tips that may be useful:

1) Be patient and as methodical as possible.  Note TwoTired's technique for troubleshooting a set of coils. Flailing will not likely save you time, nor will it provide good information if you ultimately need to post a question.

2) Check the FAQ and search the archives for specific troubleshooting procedures.  Important circuits, such as the charging system, have been extensively covered, while other endemic SOHC/4 problems, such as melting fuseboxes, have been answered numerous times.  When searching, look especially for posts by TwoTired, HondaMan and other experts.

3) I had a prof in business school who would literally yell at us, "Work the numbers! Work 'em backwards!"  The same applies to electronics troubleshooting.  It often helps to start with the component(s) that are not working and work the problem backwards. 

4) If the symptoms involve only a single component, pull it and test it or replace it with a working part.  If that fails to provide a solution, or if the problem involves multiple parts, get the wiring schematics for your model.

5) It is very difficult to do serious troubleshooting without a wiring diagram.  If you are intimidated by wiring diagrams, start with this Simplified Wiring Diagram from hondachopper.com. Next, I always find these Interactive Wiring Diagrams to be helpful.  The year in these diagrams may not match your bike; however, the ability to show and hide circuits makes it easier for me to visualize the problem.  You should refer to the specific wiring diagram for your bike when doing the actual electrical work on it.

6) Now that you have an understanding of the circuit involved, work it backward.  Start with the component you most suspect and work your way, as much as possible, around the circuit.  Use the ohmmeter to check switches, wires and connectors because these are likely points of failure on old bikes.  Worn wires often break connection or wear to the point that they short to ground. 

Electrics may seem like voodoo at first; however, failures are discrete and quantifiable.  Plus, when something does not work, there is a specific chain (circuit) that can be mapped from the positive to negative battery terminal.  Good Luck!

[SteveD CB500F]

Here's a bit of history from Two Tired for those interested in such things.

In the beginning there was a need for electrical power.  So, a battery was placed on the bike, and it was good.  The rider rejoiced with spark for the motor and lights that shown brightly day or night.  Alas, power is elusive and spreading photons throughout the countyside and igniting liquids brought along for the ride, soon depleted the chemical activity in the storage device known as the battery, and the outlook became dim.  Thus the need to replenish the battery was born.  The despirited and highly annoyed rider, now walking, commanded his #$%* (the creator of things rolling) to amend his creation so constant enlightenment could be attained.  The big B scoured many other creations and noted that generators and even more efficient alternators, would supply power to replenish the battery as long as it was provided rotational energy from the motor.  The arranged marriage of devices was consummated, but soon after the nuptials, each declared irreconcilable differences.  Big B then found each of the newlyweds marital aids to create a lasting bond, til death do they part.   For the battery, a rectifier was joined between it and the alternator which made the crude power thrusts from the alternator acceptably steady and firm as received by the battery.  For the alternator, a Voltage Regulator was placed to communicate to the alternator when the battery needed a strong partner or a passive one.  In another story, there would be dancing in the streets.  In this one, the rider noticed that the bike was running again, slapped the big B asside and rode off speading photons and igniting liquids into the sunset.

And that folks is how it really happened..

[SteveD CB500F]

From oldfordguy:

The heat shrink that I use is specifically for waterproof applications (not the junk you buy at the department/auto parts store). 

It is lined with a waterproof, heat activated adhesive that you can see seep out the end of the tubing when it is shrunk with the heat gun. 

Check this link: www.insulationplastics.com/210211.htm 

It is available from electrical supply houses such as Mouser, Digikey, etc.  It is a little thicker walled than the ordinary stuff, but for applications exposed to the elements it really makes a difference.

Matt

[SteveD CB500F]

There's a lot on this in the "General" FAQ:

http://forums.sohc4.net/index.php?topic=2894.msg154100#msg154100