No turn signals or brake lights - STILL

[liljohn]

Ok, here's the situation. I have no turn signals or brake lights. It's not an uncommon problem I know, so I've read all the threads I can find here (and have started a couple of my own).

Up to this point I have:
A) Checked the ground and the wires at the flasher module, including re-mounting the thing with new bolts.
B) Disassembled, cleaned and tested the multiswitch
C) Dissasembled, cleaned and tested the turn signal switch, including sanding and cleaning the grounding area on the steering wheel tube

NOTHIN.

I've got all my Deuce manuals back in Ohio, not here in Michigan where my Deuce is. Anyone have the appropriate wiring diagram they could post so I can check this stuff out?

Can a shot flasher unit cause the brakelights to not work, too? Is there any way to test the flasher unit to see if it's working?

I'm reaching for straws here... I need to have this thing legally on the road at the end of December, and I'm not home much to work on it....

Thanks in advance, guys!

 

[Recovry4x4]

The flasher unit can cause you to have no brake lights as well. Looking like its the unit.

 

[liljohn]

Ok. I'll start poking around for a replacement.

 

[Recovry4x4]

Also, try this link. Its for a PDF of the wiring harnes.
http://www.steelsoldiers.com/index.php?name=PNphpBB2&file=download&id=1573

 

[cranetruck]

This is from a 5-ton truck, but should generally apply to your deuce.

You can test the flasher on the work bench by connecting 24vdc to "B", ground "C" and hook a light bulb from "A" to ground.
As long as the 24vdc is applied, the bulb should flash about 80 times/minute.

 

[liljohn]

Awesome, thanks Cranetruck...

You know I think when I finally get this thing solved I'm gonna write an article bringing together all the great info I've gotten on this problem. A front-to-back diagnosis and repair guide for this situation.

 

[cranetruck]

It would help to know what IS working and in what position your 3-lever switch is in.

 

[liljohn]

Everything else works properly (including marker lights when set). No bulbs are burnt out. But left and right turn signals, hazard lights, and brake lights do not function.

I've tested the turn signals and brake lights in literally every configuration possible on the 3-lever switch.

Anyway I just got done testing the flasher unit. This is what I found:

I have 24volts out to the unit, so everything up to there looks fine.

With 24V applied to B and C grounded, I put a voltmeter from A to ground and got a reading of 11.24 volts, steady. Now granted a voltmeter isn't very good at picking up something like flashing, but if there were any variation in the current I wouldn't get a steady signal like that.

But the interesting thing is when I connected a lightbulb, I get: Nothing. It doesn't light up at all. I tried it with two seperate bulbs with the same result. I also tested the second lightbulb on another 12V source both before and after testing the flasher unit, and it worked fine, so I know I didn't burn it out.

So anyway, looks to me like the flasher unit is shot. It's putting out 11V, but basically 0A. Sounds like a short...

 

[liljohn]

SUCESS!!

I was thinking, and it stood to reason that if I shorted B & A together, then flipping the turn signal switch would result in the appropriate signals being solid on. I gave it a shot and it worked! Brake lights, too!

So now I know for sure what the problem is. I also have a nice little tidbit of info if this ever happens again. Shorting those pins together will at least give you brake lights, which, if combined with hand signals, can keep you legal enough to drive it home safely if needed.

I am now officially one happy camper. Thanks, guys.

 

[Recovry4x4]

Good troubleshooting Brian! Glad its been solved.

 

[ONTOS66]

And THAT folks, is what we call TEAM WORK! Great job all around, especially those that didn't actually get their hands dirty ... just their minds (?)

 

[liljohn]

SUCC.... CRAP!!!!!

Got my new flasher unit from Saturn Surplus (great dealing with them as always).

Plugged it in, turned on the left turn signal, flash flash flash, awesome.

Turn on the right turn signal.... funny noise... funny smell... flasher unit is very warm and now instead of A broken flasher unit, I have TWO broken flasher units.

!@#$(&&*!@#%(*!@#

If I weren't such a friggen moron I would have thought ahead of time that maybe, just maybe there was a short in the system that fried the first one, instead of just assuming it went out due to old age and abuse.

Anyone want a nice looking paperweight? I'll give it to you at cost... only $50....

*sigh*

 

[Uglyranger]

New flasher on ebay with a buy-it-now price of $35
http://cgi.ebay.com/ebaymotors/M715...egoryZ46093QQihZ019QQitemZ290064205054QQrdZ1w

I just put one in my M151A along with the 3 lever llight switch I fried at the same time. My short was in the left rear tail light.
Oh, well
Ralph

 

[liljohn]

Thanks, but already have a new one on the way.

Did what I SHOULD have done before I hooked the new one up, and plugged my little cheapie radio shack multi-tester up to the flasher unit plug. Hit the left side - 2A. Ok. Hit the right side.... went off the scale at 20A....

Now comes the ever-so-fun task of finding the dead short I seem to have. *sigh*

The good news is when I get the NEW new flasher unit I can drive the truck, so long as I don't turn right...

 

[liljohn]

Well it appears the culprit has been found - and that my first assumption that the signal unit just died may not have been wrong.

After a bunch of troubleshooting, I tracked the short down to the turn signal switch. Opened it up and viola! It wasn't hard to see - a wire pinched in the case, with the insulation scraped off and shorting straight to ground.

However, back before I knew my first flasher module was shot, I had that turn signal open, cleaned it out and checked it, then re-assembled. This problem was obvious enough so that I KNOW I would have caught it if it had been like that before... which, sadly, means I did it....

But the good news is the problem is really, truly found this time!

Also, in the process of getting this fixed, I've done a lot of work on coming up with some handy references for diagnosing electrical problems, throughout the deuce. I will post them here when I'm completely done, but I can say I think you will all like them.

 

[rampli]

What a great thread! The turn signal on my m35 has never flashed. However you could move the lever back and forth to "Manually" flash the lamps. I had convinced myself that this was the intended operation. This works well until you try to brake, shift, turn, and flash at the same time. I'll have to check it out. I bet the previous owner jumped A and B together instead of replacing the flasher. Thanks!

 

[mangus580]

Rampli... the twice that my flasher broke... it would allow me to do just that. I would suspect you have a bad flasher. (although I have seen other bad ones that dont come on at all)

 

[jkelly66]

OK heres my problem: I have turn signals tail lights ect. no brake lights. I do not have any juice going to my brake light switch and I seem to in and out of the flasher. Could it have anything to do with the 3 lever switch?
Any help is apriciated
John

 

[gimpyrobb]

JK66, When I had your exact problem, it was the brake light switch. Pull the plug out of it, connect a DMM to each lug and check continuity(sp?). Thats how I figured out it was bad. If you have no continuity(with the brake pedal pressed), its bad.

 

[jkelly66]

ok thank Ill try that tomorrow