95 fld bad blinkers

By relay, do you mean just a standard relay or the actual flasher itself? Usually the flasher looks like a relay but is about twice as tall. Not sure about the Freightliner but some will have 2 flashers. 1 for turn and 1 for 4 ways.

 

It will definitely smoke when power is shorted directly to ground..

This type of diagnostics will cost $$ to fix, Your buddy needs to get the assistance of someone with electrical knowledge..
He is obviously lacking in that department..

.. Philip

 

Smoke is definitely a direct short to ground. Did it smoke when the flasher was installed or just when he jumped it? If it only smoked when he jumped it, is it possible that maybe he jumped power directly to the ground by mistake?

 

One bit of advice I will give from experience is if you are going to jump circuits, use an inline fuse in the jumper lead with the fuse matching the amperage of the circuit you're testing. That way you won't accidentally burn down the truck if you accidentally short power to ground.

 

A better way would be to make a jumper for the fuse socket, with a light bulb instead of a fuse...

The brighter the light, the more of a ground, when the light is off, there is no circuit (to ground or otherwise)

... Philip

 

FLD's do not use a flasher, the flashing is controlled by the warning light panel, which triggers the relay on and off to flash. Most of the time it is just the relay or a bad connection, Terminals 85 and 86 on the relay will be the ones to trigger the relay. I'm pretty sure that the light bar will turn the ground on and off and the other will have constant power. If I'm wrong, 1 will have constant ground and the other will flash power. The 30 terminal on the relay should have power, the 87 is the one that powers the lights through the signal stat. So if you jump the 87 and 30 terminals, your lights should work, but not flash. That will verify if that side of the circuit is working correctly.

If you find that you are not getting a flashing signal to the relay and you've checked the wiring, then the flashing unit in the light bar is bad, you could replace the panel ($$$) or just rewire it for a standard flasher. I have instructions on wiring it for a standard flasher at work, I can dig it up if you need it. You could find a used light bar in a junkyard, but there are a few different indicator light configurations, so make sure that the lights are the same place as what you have. I know someone who got the wrong one and his heated mirror light was is engine warning light and when he turn on the heated mirrors, the load light indicator came on.

 

Here is the service bulletin on bypassing the light bar and adding a regular flasher.
http://ww2.justanswer.com/uploads/gowest/2012-03-17_172933_fld_signals.pdf
It also shows the wiring diagram that may help diagnosing the problem. The light bar does control the ground the the relay. So the 86 terminal should cycle ground/open to activate the relay and make the lights flash. If it doesn't, verify that you don't have a wiring problem by checking for the same thing at pin D13 on the light bar.