Topic: Wiring harness help, part deux, two, sh'tayim, dos, etc...

[SD750F]

I again ditto TwoTired's comments. The battery condition has a major part in a good charging/rectifier system. Also if you remember if the bike was running in both instances you mentioned above Medic09? If you have a bad diode in your rectifier and the reverse leakage is higher than spec, you could be dumping some of your battery back into the alternator coil and ground...

The non-active static test should have much different results than what you described. Please review your meter's instructions on the section for diode check and make sure that all wires have been disconnected. If they are not, the diode check will have alternative current paths and cause erroneous readings.

Also a internal crack in the rectifier assembly could provide the good one time, bad another condition you described.


Scott

[medic09]

I again ditto TwoTired's comments. The battery condition has a major part in a good charging/rectifier system. Also if you remember if the bike was running in both instances you mentioned above Medic09? If you have a bad diode in your rectifier and the reverse leakage is higher than spec, you could be dumping some of your battery back into the alternator coil and ground...

Well, battery was charged when I started.  Having said that, the battery's condition is suspect.  I had neglected it, and the electrolyte was down in two cells.  Added distilled water last week, but the battery still takes longer to charge on the charger than our other bikes', and it draws down faster.  After today's testing, I had to put it on the charger as it was struggling to start the bike this evening, and showing only 11 volts across the posts.

The non-active static test should have much different results than what you described. Please review your meter's instructions on the section for diode check and make sure that all wires have been disconnected. If they are not, the diode check will have alternative current paths and cause erroneous readings.

Inexpensive meter=next to no instructions.  The meter produces 1mV for diode test.  I removed the rectifier from the bike, so it is certainly disconnected.   BUT, I reread your instructions, and I goofed a little.  Not knowing anything about a rectifier's anatomy, I had checked just the three wires going in to the rectifier.  This time I notice that those branch off to six little post doodads.  Diodes? I ask.  So this time I did the test on where the wire goes into each of those six little post doodads.  With red test lead at the red wire, all give no reading (meter starts at 1 and stays there).  When I reverse the test leads, I get values between 516 and 523, I presume that's mV.

So, whatever else we find out, I'm thinking the battery is suspect in any case.  I can't see if crud is building up starting at the bottom of the cells, but I did let it run low on 'lyte as I noted.  Also, the fried wires leading right into the rectifier are still problematic even after my repair.  I may have to replace this just to have stable wiring.   

Thanks, as always.

Also a internal crack in the rectifier assembly could provide the good one time, bad another condition you described.


Scott

[medic09]

Bump.

Continuation about my previous comment/question re: battery condition.

How easily should a battery run down?  How long should it take to recharge on a Battery Tender Jr.?

This battery ran down after starting and running the bike at low rpm maybe 4 or 5 times over two days.  It's been 12 hours on the battery charger, and the charger is still showing it not fully charged.  (When I put the multimeter on it, it show 13+ volts.  )  Our other bike batteries seem to charge up faster, using the charger indicator light as a guide.  So, when I ran it with the electrolyte down (I don't know for how long), did I kill the battery?  It's not that big a deal to run down to the local Batteries Plus and get a new one; I just need to know how to make the decision.

Similarly, some of the wiring running right into the rectifier is still pretty brittle.  I've repaired as close up to it as I can.  A new one from the Oregon guy is about $45.  I don't have money to burn, but I need my daily ride to be reliable come spring; especially since we're planning on doing some short tours as well.

Suggestions?

BTW, I wrote earlier that my meter didn't show decimals when checking voltage.  I guess I have to set it to the correct range, eh?  Just figured that out this morning.     In my novice defence, the instructions for  this meter are really useless.

Thanks!

[TwoTired]

While I have a tendency to believe that your battery is weakened.  It is very hard to tell without knowing your charger specifics (Brand/model number or its charge specifications), and/or performing a load test on the battery.  Knowing the specific gravity of the electrolyte would help, too.

Does your bike have the stock electrical loads?  Halogen HI watt headlight?  Dyna coils?

To restore a good battery to full charge state takes about 120% of the energy removed.  The chemical to electrical conversion is not 100% efficient in either direction.  So, you have to put in more than you take out.  A deeply discharged battery will take much longer to peak up than a partially discharged battery.  I have a yuasa smart charger that will take 2 days to charge up to the 14.5v peak when my 550 batteries are run down deeply.  However, if I boost it first with a 6 Amp charger for 15-20 minutes, it only takes a few hour for the Yuasa Charger to finish the peak up job.  WARNING!  I can cheat this way because I know what voltages to look for and what signs the battery/meter gives during the charging process.  If you do this fast charging wrong, you can damage the battery permanently.

The stock battery is rated at 12V - 14AH (amp hours)  This roughly means it will supply a 14 amp load for 1 hour.  The stock bike, at idle draws about 6.5 amps from the battery.  So, in theory the bike with all its lights on can sit and idle for a bit over an hour before the battery drains enough that the voltage is too low to fire the spark plugs.  Obviously, a weakened battery won't last that long.  Further, the electric starter draws 150 amps while it is engaged, and that takes a bunch of the battery capacity away with it's use.  The alternator has to run above 2k RPM about 10-20 times longer than the starter was used, just to put back the energy used by the electric starter.  (again assuming the stock electrical components)

Without knowing how long or how deeply you operated your battery in depletion mode, or how much energy you have put back into the battery, it isn't easy to predict with certainty if your battery is damaged.

Cheers,

[SD750F]

Medic09,

Here is a way to look at the charging circuit and the battery...

You have a small water container, lets say a 1 gallon container with a 1/8 inch diameter hose attached. The bucket is attached to a wind mill pump and has an output that is just above your gardens water requirements. Now this hose can supply all the water your garden needs in normal circumstances and only requires a secondary supply of water when there is a period of drought. But you do have a secondary supply of water lets say in a 55 gallon drum with a 1 inch diameter line attached. Now both are capable of suppling your garden's need but are controlled by a spigot that only opens when you have a deficient or a need for more water.

So you are going along with your garden only needing a small stream of water and your 1 gallon supply (alternator) services the need. Now you enter a dry period (low alternator output/idle speed or extremal high operating power requirements that is above original design specifications or due to bad equipment) and you have the secondary supply (battery) provide the extra water required to maintain your garden (normal bike operating functions). This is good for a short period of time without causing a long lasting impact on the secondary supply. Your wind mill pump is working but now you have taxed it and relying on the secondary water supply (battery).

Okay the drought continues and the secondary water supply is damaged and actually contains only 25% of the original 55 gallons. Now how long can you maintain your garden with it's current water needs? And what if the water needs should increase due to a much greater demand? Now here is the worst condition. The secondary supply is dry. So now your wind mill powered supply of water with it's 1 gallon reserve is dumping all the water into a large 55 gallon drum. Does your garden get any water?

This is a simple way to look at the whole power generation and consumption system. I hope it helps to provide another perspective...

Scott

[medic09]

Scott,

Lovely metaphor.  You should have gone into English Lit instead of/along with electronics!

That said, your comparison leads me to think that the battery (which suffered undetermined damage being run on low 'lytes for an undetermined time) may well do with replacing.

Hey, on another note, I hope we never get grounded in South Dakota; but in my business you never know.  Are you at one of the airports there?

Mordechai

[SD750F]

Mordechai,

Well yes and no... I am close to the largest (besides Elsworth AFB in Rapid City) airport in South Dakota. Sioux Falls is my town and I do not think I will ever get grounded, well I hope not...

I own part of and fly three different airplanes. Skyhawk 172, Piper Archer III, and a Piper Dakota. I also own a Hot Air Balloon and have flown gliders/sailplanes in my younger days. Next I want to try helicopters!

Please let me know if there is anything I or we here on the forum can do to help. I wish that your meter was a little better, but I think that all is okay with the readings your described.

I too think you have a battery situation going on...

Scott

[medic09]

It's a poor workman who blames his tools...the meter isn't the problem; it's the user who didn't know to set it for the appropriate range.  In the end, our conclusion is probably unchanged.  Batteries Plus, here I come!  I may even splurge for an AGM battery ($50).

Thanks a million.  I got a lot accomplished, and learned a ton!  I have wiring that I can rely more on now that I've been through it.  Next task, carbs and tuning! Woohoo!   

(When, I hear someone ask, are you going to get your schoolwork done? Hmmm....)

[angeldeville]

Mordie,
You are now officially the CB750 electrician for the Santa Fe/ ABQ area..

[SD750F]

Mordie,

I had too many things going on in my office at the same time. Sure if you are ever in the area, look me up.

Scott

[medic09]

Mordie,
You are now officially the CB750 electrician for the Santa Fe/ ABQ area..

Oh yeah?  Does that mean you'll let me muck around the electrics on YOUR bikes?    

[medic09]

Thanks all.  After a long, tortuous thread and all your patience I officially retire this thread! 

Don't worry.  Just wait till I start on something else. There'll be plenty of annoying, naive newbie questions! 

Scott, if MedFlight ever gets stuck up your way, I'll give you a call.

[SD750F]

And I will look you up the next time I am in Albuquerque flying my balloon in the Fiesta in October...

Have fun and enjoy!

Scott

[angeldeville]

Mordie,
You are now officially the CB750 electrician for the Santa Fe/ ABQ area..

Oh yeah?  Does that mean you'll let me muck around the electrics on YOUR bikes?    

unfortunately all mine function, and don't need any "mucking".... 

[seaweb11]

can I borow your meter....mines Fu&ked..or is it the user

[750goes]

Seaweb,

I believe the good meters are called Fluke - although I think you meant to mispel  the brand of yours

[medic09]

Seaweb,

I believe the good meters are called Fluke - although I think you meant to mispel  the brand of yours

 

Hey Derek,

We know in my case it was the user...

[seaweb11]

Ya that's it. Mines Fluked    .....it would be a fluke if I pulled it out of the drawer

[TomC]

Hi medic09
     A cheap ball type battery tester would tell you if you have a bad cell or two in your battery. They should be cheap at a chain discount auto parts store.
     TomC

[medic09]

Thanks, TomC.

I was trying to get a hydrometer that would give me an idea of actual specific gravity.  As it is, I decided to just go ahead and replace the battery.  All the other culprits had been pretty much ruled out.  I'm just glad we all survived the ordeal of getting me through Motorcycle Electics 101.