electrical diagnosis help, please

[lowrange]

dash right turn indicator stays on

right turn signal doesn't work (front, rear and trailer)

flashers don't seem to work, or work sporadically

left turn signal works just fine

Multi-switch? Something a little cheaper...maybe...?

It's a Freightliner.

[allan5oh]

Try changing the relay.

Edit:

You may also have a burnt bulb. It will do exactly as you described.

[lowrange]

Try changing the relay.

Edit:

You may also have a burnt bulb. It will do exactly as you described.

Ah, so there is hope for something cheaper than a multi-switch! That's good, because I've been working off all the little bugs, but thats still like $500 to replace a window tray and to replace a window washer pump. I could use so revenue before fixing something new.

I'm curious about the bulb, though, since the turn signal won't work on the front, back or on the trailer.

[mike3fan]

sounds like a short,does it do it when not plugged into the trailer? if not then you may have a wire shorting out in the pig tail take it apart and rewire the pigtail,this just happened to me 2 weeks ago.The shor tmay be in the trailer,but start by unplugging it on your end first.

[lowrange]

sounds like a short,does it do it when not plugged into the trailer? if not then you may have a wire shorting out in the pig tail take it apart and rewire the pigtail,this just happened to me 2 weeks ago.The shor tmay be in the trailer,but start by unplugging it on your end first.

Huh? Now, that's interesting, too. What I did, I went to sleep, and now it's working again! I'm a mechanical genius!

That's a good point though, I just picked this trailer up. Maybe it's related to the trailer somehow. Either way, sounds like it's not the mult-switch- happy, happy, joy, joy... I'll keep watching it, maybe jiggle the pigtail if it does it again, unplug it, maybe I'll pop in a relay. There're a few things to try.

[partssman]

Check your bulbs on that side.......some vehicles use the steady light to indicate a burnt out bulb.

You know the 1157 bulb has 2 elements .... so check 'em close

[flood]

dash right turn indicator stays on

right turn signal doesn't work (front, rear and trailer)

flashers don't seem to work, or work sporadically

left turn signal works just fine

Multi-switch? Something a little cheaper...maybe...?

It's a Freightliner.

a bad ground or light socket will also do all of this. if you have a bad ground or bad light socket the power from you daytime running lights will back flow into the turn signal system on that side. (power will always look for a ground)

when it's doing it just unplug the front turn signal bulb and see if the dash light goes out, if not do the same with the side marker/flasher then the tail light on that side.

if the dash light goes out then you know which one is bad, then just check to see if the ground is bad. if it's not the ground then changing the light socket should fix it.

also check and make sure you have the RIGHT bulb..! my CADDY uses the same taillight bulb as a freightliner side marker/flasher but if i use the wrong one (looks the same) my turn signal on that side will only work when it wants to and yes the dashlight will stay on when i have the parking/head lights on.

[Larry Heyns]

If both dash lights came on with the markers, I would have suggested improving the ground between the fifth wheel and tractor frame, etc. Juice is trying to get back to the batteries and traveling through the light cord when it should be traveling back through the frame.

[Kranky]

If both dash lights came on with the markers, I would have suggested improving the ground between the fifth wheel and tractor frame, etc. Juice is trying to get back to the batteries and traveling through the light cord when it should be traveling back through the frame.

That's what the ground wire (that 10 gauge fat white wire) in the trailer cord is for.

The trailer isn't supposed to have to "pull a ground" through the 5th wheel, nor would the 5th wheel be a reliable ground with the grease at the 5th wheel/trailer interface, and the random relative movement between the 5th wheel plate and the trailer.

Now, along that line of thought, a problem with the ground circuit in the trailer cord or elsewhere could cause a voltage "feedback" issue which could result in undesired operation of other lights when turn signals are on, as the voltage seeks a return to ground through the filaments of other light bulbs on the trailer or tractor.

[lowrange]

As I said, when I woke up the next morning the problem was gone. Somebody smarter than me might have realized that 1) I had just picked up this trailer and 2) my turn signal only failed to work when the headlights are on....

Drum roll please...I got it into the TA and the problem ended up being the way one of the side marker lights was wired- I forget if it was also a blinker- again, my failing, but I went to Taco Bell instead of standing there trying to see the exact problem. All I know, TA fixed it, the company paid for it, and my tractor ain't broke! I see many of you were on the right track, too.

[heavyhaulerss]

All I know, TA fixed it, the company paid for it, and my tractor ain't broke



AND I was just going to tell you how to fix it.