Topic: Figuring out electrical nuances

[Laminar]

I got my cafe project all wired up on Saturday, but there are a couple issues I'm trying to figure out. Some of the wiring is non-stock, so I'll try and describe what I've done to the best of my ability.

I'm running an aftermarket HID kit that I wired in, and I'm using LED turn signals at all four corners.

Both systems are giving me trouble.

Starting with turn signals:

Four LED 2-wire turn signals. I'm using a two prong electronic flasher that worked on my '77 CB750. The O/W and LB/W connectors in the main harness are unused. The positive wire from each turn signal goes to either O or LB, and the negative wire from the turn signal goes to G (green). In its normal state, all four turn signals are off. When I flip the turn signal switch either direction, all four signals come on and stay steady until I flip the switch off.

Here's how I understand the stock turn signal system:

+12v comes from the battery (R), through the main fuse(R), through the ignition switch (Bk), into the headlight bucket (Bk), into the turn signal buzzer (Bk), out of the turn signal buzzer (Br/B), into the left hand control "B," as designated by the manual.

+12v also comes from the headlight bucket (Bk), into the winker relay (Bk), out of the winker relay (Gr), into the headlight bucket (Gr), and then into the left hand control "WR."

Left hand control designation "L" goes to the headlight bucket (O), then to the positive connector of each left blinker and to one side of the turn signal indicator light.

Left hand control designation "R" goes to the headlight bucket (LB), then to the positive connector of each right blinker and to the other side of the turn signal indicator light.

The negative side of each blinker connects to ground (G) in the headlight bucket, which is grounded to the frame above the coils.

The manual lists what I assume are switch positions: L2, L1, N, R1, R2.



What is the difference between L1 and L2? It appears from the diagram that for L1, the winker relay is connected to the turn signal positive. In L2, the winker relay connects to both the turn signal and negative side of the buzzer, so I would assume the buzzer completes its circuit through the turn signal.

Since I'm not using the turn signal buzzer anymore, would it be necessary to connect Br/B to Bk? I did that when I wired it up, but in retrospect I don't think I need to, as that would seem to give +12V to the blinkers, regardless of what the winker relay is doing.


****end of part 1****


Part 2: Headlight

The kit I bought has a relay box. The box has several connections:
- Battery +
- Ground
- Ballast
- Headlight bulb "high" switch
- H4-style plug (three wires: Common - black, Low - white, High - red)

The first four were simple. The H4 plug is where it got tricky. It's designed so that you can connect your factory H4 plug directly into the kit. Since I don't have that, I had to improvise.

When I bench tested the kit, I found that putting +12V to the white wire (with black grounded) turned the light on. Keeping +12V on white and adding +12V to the red wire activated High mode <-INCORRECT - there is an electromagnet in the bulb's shield that, when activated, moves the shield to change the beam pattern.

Here's my understanding of how the headlight wiring works:

+12V from a black connector in the headlight bucket goes into the starter button (Bk) then out of the starter button (Bk/R), then into the headlight bucket (Bk/R), then to the fuse box (Br/R), back to the headlight bucket (Br/R w/ yellow tube), then to the left hand control (Br/R). At this point, the hi/low switch directs power to either white (low) or blue (high). There's a splitter in the headlight bucket that directs power to both the headlight and the high beam indicator, each of which grounds at the same green multi-connector in the bucket.

Here's what I did - the Bk/R wire to the right hand control was eliminated, because I don't want the HID flashing on and off, as that shortens the life of the bulb. I connected the black (ground) HID wire to the unused green multi-connector in the headlight bucket. I connected the red (high) HID wire to the blue splitter in the headlight bucket. I connected the white (low) HID wire to a switch on the bike. The other end of the switch connects to a black multi-connector in the headlight bucket.

The white wire from the left hand control was taped off and unused.

The Bk/R to the fuse box was connected to a black multi-connector in the headlight bucket to provide +12V when the key is turned on.

Here's the problem I'm having; with the high/low switch in low, the headlight is off. When I turn my new switch on, the headlight comes on low just as it should. When I turn the high/low switch to high, the headlight switches to high, but then randomly jumps back and forth between high and low. This happens without any disturbances to the wires - I'm not moving or shaking anything, it just flickers back and forth between high and low.

Also, with my new switch turned off and the high/low switch in high, the headlight will turn on in high mode (with the same flickering problem as before).

And the high beam indicator doesn't turn on in either case. This could just be a bad bulb, that's something I need to check out.

Any ideas on where I might have gone wrong on either issue?

[Nikkisixx]

Man, that is a lot of 411!  Off the bat I think you have a  blinker relay problem unless your '77 has led turn signals?
"I'm using a two prong electronic flasher that worked on my '77 CB750"

LEDs prefer a specific type of relay such as:
http://forums.sohc4.net/index.php?topic=45092.msg471304#msg471304


Now the headlight?   

[Laminar]

Man, that is a lot of 411!  Off the bat I think you have a  blinker relay problem unless your '77 has led turn signals?
"I'm using a two prong electronic flasher that worked on my '77 CB750"

LEDs prefer a specific type of relay such as:
http://forums.sohc4.net/index.php?topic=45092.msg471304#msg471304

Everything I've read in the past said that LEDs prefer an electronic flasher. I've never heard (until now) that LEDs require a 3-prong flasher.

[Nikkisixx]

I just sifted through about 6 threads on the subject and it seems the 3 prong with the third to ground is the SOP for LEDs.  LEDs don't pull enough to trip the "thermal" type relay, so you need an electronic version.  Of course, individual results may vary.

I think you said all four signals are comming on at once and you have the buzzer hooked up somehow?  Nix that, just unhook the buzer completely and see if you still get a 4 way light show.

[Laminar]

I'm using a two prong electronic flasher

...

Since I'm not using the turn signal buzzer anymore, would it be necessary to connect Br/B to Bk? I did that when I wired it up, but in retrospect I don't think I need to, as that would seem to give +12V to the blinkers, regardless of what the winker relay is doing.

[Nikkisixx]

"I'm using a two prong electronic flasher"

Yup, too much 411 
And the buzzer?  Is it potentially backfeeding the circuit and turning on all the lights at once?

[Laminar]

No buzzer installed, so I connected Br/B to Bk. I'm thinking that might be the problem. We'll see tonight when I get a chance to take a look at it.

[Laminar]

Update:

I believe the headlight problem was two things. First, when I was bench testing the headlight, I messed up, and all that's needed for brights is +12V on the red (high) wire, not on both white (low) and red (high).

Second, I opened up the left control and gave the switch a good cleaning, and it has stopped flickering between bright and not.


As far as the blinkers go, I'm still stumped. I disconnected the brown/blue wire from +12V but the same thing happens - when I flip the turn signal switch either direction, all four lights turn on and stay on steady. If I unplug the flasher, no lights turn on.

If it was just a bad flasher, I'm assuming only the two lights I want to turn on would turn on, but instead all four do.

EXCEPT

I just had a thought - although all four turn signal lights come on, the turn signal indicator doesn't. I unhooked one end of the turn signal indicator, and now when I switch the switch left, both left signals come on steady, and the same is true for the right side. So the bulb might be bad, but the blinkers still aren't blinking.

Thoughts?

[Laminar]

Any other ideas?

[HondaMan]

Here's a turn signal circuit for a 2-prong flasher, stock, from the Book.
The 3-prong electronic flashers are needed for the LEDs because they do not flow enough current to charge most 2-prong types, even if they are electronic. The low-current flasher needs its own ground.

[Laminar]

Here's a turn signal circuit for a 2-prong flasher, stock, from the Book.
The 3-prong electronic flashers are needed for the LEDs because they do not flow enough current to charge most 2-prong types, even if they are electronic. The low-current flasher needs its own ground.

Perfect, that's what I needed to know.

Thanks.

[scubes]

Here is what I found on my 74 cb550 when I did an led upgrade. For one yes you need a 3 prong electronic flasher as stated above. But also the original system was designed so that when one side was on the turn signal indicator would backfeed through the signals on the other side as a ground for itself. Now for a normal incandescent bulb this backfeed was so minimal that the lights would not light. However LEDs work on milliamps and it is enough to cause the other side to light. If you look at your turn signal indicator it probably has the orange wire and the light blue wire going to it but no ground. What you have to do is cut the wires and add a diode that has 2 inputs and one output and hook that to one side. Then just hook the other side to ground. Kuryakyn offers a kit http://www.kuryakyn.com/index.cfm/go/Home.ProductDetail/catID/16/scID/114/IMID/719 Basically on the diode you hook up the orange and light blue wires from the turn signals to the input, and the output of the diode to just one of the input wires to the turn signal indicator. Then like I said you turn the other side of the indicator into a ground. This and unhooking the signal buzzer solved this same problem on my 550. The buzzer would cause a similar problem and I think it is do to a similar problem with factory wiring design but I haven't bothered yet to really figure out the issue. I don't worry about it at inspection because most guys don't even know they are there anymore.

[Laminar]

Here is what I found on my 74 cb550 when I did an led upgrade. For one yes you need a 3 prong electronic flasher as stated above. But also the original system was designed so that when one side was on the turn signal indicator would backfeed through the signals on the other side as a ground for itself. Now for a normal incandescent bulb this backfeed was so minimal that the lights would not light. However LEDs work on milliamps and it is enough to cause the other side to light. If you look at your turn signal indicator it probably has the orange wire and the light blue wire going to it but no ground. What you have to do is cut the wires and add a diode that has 2 inputs and one output and hook that to one side. Then just hook the other side to ground. Kuryakyn offers a kit http://www.kuryakyn.com/index.cfm/go/Home.ProductDetail/catID/16/scID/114/IMID/719 Basically on the diode you hook up the orange and light blue wires from the turn signals to the input, and the output of the diode to just one of the input wires to the turn signal indicator. Then like I said you turn the other side of the indicator into a ground. This and unhooking the signal buzzer solved this same problem on my 550. The buzzer would cause a similar problem and I think it is do to a similar problem with factory wiring design but I haven't bothered yet to really figure out the issue. I don't worry about it at inspection because most guys don't even know they are there anymore.

Specifically, what electronic flasher did you use? I picked up a three prong unit designed for two bulbs per side, but that's incandescent. Now the turn signals come on VERY dimly, and they still don't blink. Further research tells me I need either an LED-specific flasher, or I need to add resistors to my LEDs. I'm not worried about the power savings, so I'll probably go the resistor route. I'll pick up some resistors and diodes tonight and see if I can't get this figured out.

[HondaMan]

Here is what I found on my 74 cb550 when I did an led upgrade. For one yes you need a 3 prong electronic flasher as stated above. But also the original system was designed so that when one side was on the turn signal indicator would backfeed through the signals on the other side as a ground for itself. Now for a normal incandescent bulb this backfeed was so minimal that the lights would not light. However LEDs work on milliamps and it is enough to cause the other side to light. If you look at your turn signal indicator it probably has the orange wire and the light blue wire going to it but no ground. What you have to do is cut the wires and add a diode that has 2 inputs and one output and hook that to one side. Then just hook the other side to ground. Kuryakyn offers a kit http://www.kuryakyn.com/index.cfm/go/Home.ProductDetail/catID/16/scID/114/IMID/719 Basically on the diode you hook up the orange and light blue wires from the turn signals to the input, and the output of the diode to just one of the input wires to the turn signal indicator. Then like I said you turn the other side of the indicator into a ground. This and unhooking the signal buzzer solved this same problem on my 550. The buzzer would cause a similar problem and I think it is do to a similar problem with factory wiring design but I haven't bothered yet to really figure out the issue. I don't worry about it at inspection because most guys don't even know they are there anymore.

Specifically, what electronic flasher did you use? I picked up a three prong unit designed for two bulbs per side, but that's incandescent. Now the turn signals come on VERY dimly, and they still don't blink. Further research tells me I need either an LED-specific flasher, or I need to add resistors to my LEDs. I'm not worried about the power savings, so I'll probably go the resistor route. I'll pick up some resistors and diodes tonight and see if I can't get this figured out.

It sounds like that flasher is not hooked up right. The contacts that go to the LEDs will be full battery volts. The flasher will flash without the LEDs even connected if t's connected right. 

[scubes]

I ordered mine from superbrightleds.com where I bought my led bulbs also. But from what I read on the DOHC sites guys have had good luck with Grote #44893 flasher relay. It's about $13 from NAPA I believe. I wish I could remember the terminal hookups on it.

[Laminar]

It sounds like that flasher is not hooked up right. The contacts that go to the LEDs will be full battery volts. The flasher will flash without the LEDs even connected if t's connected right. 

The package had a diagram showing +, -, and L. I hooked black to plus, gray to L, and the spare green connection to -.

I tried switching + and - (and this time heard the relay click when turning the power on) but still no lights or blinking. If you have another suggestion I'm all ears.

[Laminar]

I ran by Radio Shack last night and picked a couple things up.

I got 2x 8 ohm 20W resistors and a couple 1W diodes. I put one of the resistors in parallels with one of the rear turn signal and voilà, that side works.

[Laminar]

Dang. I wired up a couple diodes and connected up the turn signal indicator like scubes said, and all of a sudden both sides blinked, even without any resistors connected. Guess I should have done that first.

[fastbroshi]

Laminar's quote from first post:

The O/W and LB/W connectors in the main harness are unused. The positive wire from each turn signal goes to either O or LB, and the negative wire from the turn signal goes to G (green). In its normal state, all four turn signals are off.

I don't know about that bud. You're trying to have running lights and the turn signals right?  With regular bulb signals, all three wires are used.  Is that not the case with LED's?

Oh and I just got into that box of carb parts you sent me.  Whoever let those carbs get like that deserves to be flogged after I run over their feet with the 550 a couple of times.  Holy moly those things had a serious cocaine problem in the bowls!!

I did get that one throttle valve out, there were a couple burrs on it for some reason. Maybe a ham handed rider snapping the throttle shut.  Luckily the same thing happened on my last set and I knew what to do.

[brandon]

I ran by Radio Shack last night and picked a couple things up.

I got 2x 8 ohm 20W resistors and a couple 1W diodes. I put one of the resistors in parallels with one of the rear turn signal and voilà, that side works.

This may be a cheaper alternative for most people. Would you mind posting a couple clear photos of exactly what you did here? Thanks!

[Laminar]

Laminar's quote from first post:

The O/W and LB/W connectors in the main harness are unused. The positive wire from each turn signal goes to either O or LB, and the negative wire from the turn signal goes to G (green). In its normal state, all four turn signals are off.

I don't know about that bud. You're trying to have running lights and the turn signals right?

No.

[scubes]

I ran by Radio Shack last night and picked a couple things up.

I got 2x 8 ohm 20W resistors and a couple 1W diodes. I put one of the resistors in parallels with one of the rear turn signal and voilà, that side works.

This may be a cheaper alternative for most people. Would you mind posting a couple clear photos of exactly what you did here? Thanks!

If you're talking about installing the resistors, I personally wouldn't do it. By connecting them in parallel on the turn signal wires it creates a load similar to that of an incandescent bulb making the blinker work right. But in doing this the resistors get hot, very hot if you forget to turn the blinker off. If they are soldered on it can get hot enough to melt the solder bringing you back to sqaure one of having no signals, or possibly causing damage to the wiring or something else if they are placed where they don't get any go ventilation.

[fastbroshi]

I'm pretty sure that's what resistors are designed to do.  They soak up the extra power.  They designed to do this and not fail. 

[scubes]

Actually capacitors absorb power and then discharge it. A resistor does exactly what it's name describes, it "resists" the flow of electricity. When placed in series in a circuit it usually just cuts down current flow. But when you place it in parallel like a ballast resistor used in led lights, it creates a minor short simlulating the current draw of an incandescent bulb. Shorts create heat, which anyone who has worked on a corroded electrical connector can usually tell you because the wire isulation is usually distorted at the connector. Take a look at this load resistor kit from superbrightleds.com http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Ftail-brake-turn.html#Table5 it's towards the bottom of the page. As you can see it is encased in a large heat sink. I'm not trying to cause trouble or stir the pot or sound like a know it all for that matter. I'm just trying to share my past experiences with electronics, as well as what I've found throughout my internet searching.

[Laminar]

Some of the specific LED load-creating resistors available come inside of a nice aluminum heatsink. I did find a how-to elesewhere that used these same Radio Shack resistors, it was recommended that they be attached to the frame with some heatsink compound in between to help disperse the heat.

Of course, this is 100 percent armchair engineering (aka worthless conjecture) and it will remain as such until somebody actually tests it. Now if only I had LED turn signals, Radio Shack resistors, and a fancy new infrared thermometer. Oh wait...