Dually fender clearence lights on???

[6.9poweredscout]

I went to get in my truck before and I thought I left my markers on, I walked around the truck and ONLY the 4 clearance lights on the dually fenders were on. it's been pouring rain out for about an hour. I turned the lights on and off and they flickered then went out. they work fine with the switch now. any idea what might be going on here?

 

[lindstromjd]

Headlight switch maybe?

 

[LCAM-01XA]

It wasn't only the dually markers, your rear ICC lights under the tailgate were also on, you just didn't see them. And if you had a trailer hooked up, the entire trailer would be glowing too

Check the trailer running lights relay, it's one of the two next to the coffee can vacuum reservoir - one is for the E4OD that you no longer have, and the other is for the trailer lights and the dually markers and the ICC lights. Unplug them one at a time till you get the one that kills your lights, then replace it.

 

[6.9poweredscout]

It wasn't only the dually markers, your rear ICC lights under the tailgate were also on, you just didn't see them. And if you had a trailer hooked up, the entire trailer would be glowing too

dude... are you stalking me???? how many wires/colors are in that harness?

 

[6.9poweredscout]

Headlight switch maybe?

wouldn't that leave on the markers too? it was JUST those 4 on the dually fenders.

 

[LCAM-01XA]

dude... are you stalking me???? how many wires/colors are in that harness?

not stalking no one, just after spending hours tracing and fixing some creative wiring some previous owner of my truck had done I know all too well how the truck is wired (or at least how it was wired from the factory).

Which harness are you asking about? The one for the relay has 4 wires:
- yellow, battery feed for the relay, constant hot
- white/red, power out to dually lights (4 fender markers and 3 under tailgate) and trailer marker lights
- brown, pull coil trigger, spliced into the front marker lights harness, hot when you pull the main switch
- black, pull coil ground.

The dually markers are all spliced into the white/red wire at the same spot, their grounds are also spliced all together. So if the fenders got power so did the ICC lights. And since the same red/white wire also powers the trailer connector, and said connector at least from the factory was grounded to the same spot on the frame as the dually markers, it stands to reason that if you had a trailer connected its lights would also power up.

 

[6.9poweredscout]

Is it a common thing that they had the ICC lights? I figured it was something a po did. I didnt think about it but as soon as you said it I went and looked and it was also on... Unless you picked it up in one of my pictures I never said anything about that light being on my truck. freaky.

 

[LCAM-01XA]

Factory equipment on dually trucks AFAIK. If you have 3 individual markers right next to each other that's the factory setup still. If instead you have 3 markers on one light bar then some PO ditched the factory setup and replaced it with the bar (likely cause it's cheaper to buy a $10 bar instead of three $5 markers, sealed connections be damned).

Now, if only they worked as ICC lights in function too, not just in nickname...

 

[6.9poweredscout]

it's a 3 led bar. any idea what causes them to come on?

 

[freebird01]

i also wouldnt understate the obvious.... the duallys from what I understand have an issue with the pigtail connector thats up inside the dually fenders corroding. mine has this issue...so typically my pass side only work when they get wet right now...

also if your trailer draws too much current it will fry that relay under the hood for the tow harness like a potato chip...dont ask me how I know that one...scotch locks be damned!!!

 

[6.9poweredscout]

Yeah I pulled a handful of those damn things off. They spliced the wires in front of the fuel tank to mount the plug for the fifth wheel.

 

[freebird01]

i borrowed a trailer from my moms fiance to move some of my stuff out here....his trailer shorted and fried that relay and about a foot of the wiring to it...literally fried it...like the relay crumbled in my hand when i pulled it out...did it on hour 2 of what was supposed to be a 10hr trip...turned into 14hr trip

ended up having to fix that and rewire the entire trailer before i came home with it again...and found 15 of those stupid things through out the trailer harness,..

 

[6.9poweredscout]

I took all them off the trailer and used water tight butt connectors.

 

[LCAM-01XA]

it's a 3 led bar. any idea what causes them to come on?

A corroded connection in the fenders will cause your markers to not work, but it will not cause them to light up on their own - that's power supply issue, relay got corroded internally probably. I had the same thing happen to me with the driving lights, replaced relay and problem went away. Cut the old relay apart and it was quite nasty inside.

 

[6.9poweredscout]

You sir are more than helpful. When I did my 6637 filter I just laid the harness next to it, probably full of water....