'96 Freightliner Turn Signal Problem...Help

Hey if anyone could give me some advice i'd really appreciate it. I am a fairly new tech. I was an electrician before hand but im kinda lost now that I have exhausted all of my ideas.

The problem I'm having is with the turn signals on this rig. Everything seems to have power as it should and there doesn't seem to be any shorts to ground or anything but as soon as I go to turn the turn signal switch on the relay will start buzzing with the incriments that sounds like a turn signal but the lights don't come on. I have changed relays, switches added a flasher canister to the system...and nothing. One thing I have found though is when I put a jumper wire across the relay the lights will come on for a time and then go out(im assuming they go out because a breaker is tripping but I dont know from where cause I dont hear one). None of the relays, bulbs or breakers that I have tested are bad.

What it comes down to is I think it may be a component in the indicator light panel that could be out but I can;t be sure and my supervisor does not want to buy an indicator panel for $300 just on a hunch(understandable) but I am coming to my wits end and I have no idea where else to look. Can anyone help?
 

boone315

SPACE TRUCKING
It might be right in the signal switch itself(I own a '96 fld, it is retired) They had a recall on the signal switch a number of years back because a short in the housing. I had mine replaced due to something similar, I would have to jiggle the lever to get the signal to come on.
 
It might be right in the signal switch itself(I own a '96 fld, it is retired) They had a recall on the signal switch a number of years back because a short in the housing. I had mine replaced due to something similar, I would have to jiggle the lever to get the signal to come on.
Hey thanks for the reply. I will take another look at the switch, but because it is engaging the relay I just assumed that it works. I did change it out already but the one I switched it out with is a used one. Another thing that I have found interesting about this problem is that the breaker protecting the circuit is really hot and constantly receiving full circuit voltage, does that sound peculiar to you?
 

boone315

SPACE TRUCKING
If the trucks recall has not been updated, the signal housing will be metal(going by memory here so not sure) and be made by signal stat, if it has been replaced it will be a plastic housing.
 
Which part of the signal housing are you referring to? As far as I can tell the circuit doesn't has a flasher in it, so I'm wondering if it's the indicator panel(a circuit panel) that has a faulty component in it.
 

boone315

SPACE TRUCKING
On the left side of the column, the flasher is the little bar you pull out under the signal handle.
 
Does your turn signal switch look something like this:



It may be that there is a short to ground inside of the switch housing. That would explain why things would work for a bit when you put in the jumper, then quit. (then the breaker opens, and they quit)

Look for a short to ground.

I used to have a test light that would actually test for shorts to ground and help find them. It had different colored lights for positive and negative circuit flow, and an accessory that you could use to "sound" along a harness to find an open or short to ground. My MAC tool guy sold it to me.
 

boone315

SPACE TRUCKING
Yep, that is the one that needed to be replaced, three little wires in there, they will break off/wear out due to poor design and short out. Mine actually had one big screw I think, been a few years.
 

bigyellowpete

Town Bike
Supporter
Another place to check for a short is in the wires coming from the switch down the steering column and where any trim pieces may have pinched/rubbed them through. I had that happen to me after removing the cover once around the steering column.
 

pop

Well-Known Member
most of the time the wire for the light in the switch brakes off. take the bottom cover off an pull the wire down an cut it off at the board.
 
Try to replace the light cord on back of the cab and replace the relay ts.you can first test by unhooking the cord and putting new relays in. the light cord for trailer may have a short from guys grabing the cord instead of pig tail its self.burns up relays by grounding out.
 

Duck

Quack
Supporter
On the left side of the column, the flasher is the little bar you pull out under the signal handle.
That's what the problem was. The original poster only has 3 posts, and he asked his last question right before Boone said where to find that flasher. No more replies from the guy so I'm guessing Boone solved it and the guy forgot to come back and say thanks and post pictures of beer.
 

boone315

SPACE TRUCKING
That's what the problem was. The original poster only has 3 posts, and he asked his last question right before Boone said where to find that flasher. No more replies from the guy so I'm guessing Boone solved it and the guy forgot to come back and say thanks and post pictures of beer.
And yet no gratuity for the help. what's up with that?
 
And yet no gratuity for the help. what's up with that?
All the stuff I've helped with in my days, and I never even got a batch of brownies for my efforts. That's all I really want is a decent batch of brownies.
 

boone315

SPACE TRUCKING
I sold my '96 fld last weekend, kinda regretting it.
 
Can someone please help to shed some light on a few issues we've been having with our truck. We have a 2002 Freightliner Century and we've been having problems with the windshield wipers constantly blowing a fuse once the truck gets on the road. As long as it sits they work fine. We changed out the engine harness. Also the turn signal lights and the marker lights work when they want.
 
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