Last week I noticed that my tail lights and license plate lights don't work when the headlight switch is on. Rear turn signals work, flashers work, back-up lights work so the lamps are good. Fuses are good, relay is good. Here's the thing: I had installed a Hoppy trailer-lighting harness about 6 mos. ago. Even after removing it, my rear running lights and license plate lights still don't work. What should I try next?

 

My bad, '02 Ram 1500, 4.7L, V8.

 

I helped my buddy put on a trailer wiring kit and he had probelems with his truck later too. Except when he stepped on the brakes, the brake lights wouldn't work. The running lights and blinkers would work fine. I checked all the bulbs, all the fuses, all the wiring, and even uninstalled the harness and nothing fixed the brake light problem. His was a '00 5.9, though.

 

I had the same problem last year, I had to replace the whole fuse box. It cost about $500. I tried everything else, i even tried to get into the fuse box but couldn't. I didn't have any mods done to the truck either. Hope that helps

 

Having same problem here - does anyone have a suggestion within reasonable accomplishability?
I have checked the bulbs, fuses, relays, and wire harness, but to no avail. need help as I'm trying to move out of state and don't want to have to travel solely during the day. thanks

 

OK Thank you for the informations...

 

Hi all!

I am having the same issue with my park lamps Front and Rear. Checked everything (relays, fuses, etc.) park lamps only work if I jump the relay.

Fraenkyboy indicated that the FCM was the problem but I did not see a reply or update since the post. Can anyone advise? I am out of ideas here so do I change the FCM?

TO DATE I HAVE:
Changed headlight switch
Checked all relays
Checked all fuses
Checked all bulbs
Checked all connectors
Ckecked all chassis grounds
Verified 12v to relay (30, 86)
Verifiy relay working by applying ground to (85) and lights work


HELP!

 

Had the same problem here. Had to replace the under hood fuse box.

With this many problems all of a sudden (dealers actually have the boxes on back-order) you'd think a recall would be issued.

 

Definately DEFINATELY...............it's the fuse box.
Do a search for the many items and replys I have made to describe and fix the "running lamp problems".
Replace the whole Power Distribution Module...............fuse box to you and I and your problem WILL be solved!
There are corrosion problems seated deep within the fuse box, where the printed circuit board paths connect the FCM to the fuse box internally. These corroded paths, cause high resistance to ground, which the FCM uses to turn on the Park Lamp Relay. The FCMcannot switch on the Park Lamp Relay because of this high resistance.
There is a description of how to jumper the Park Lamp relay, to temporarily force the rear lights to work as AlexisRamdid, when he connected pin 85 to ground of the park lamp relay.
This emulates what the pathways embeded deep in the fuse box do.
My posts have a long and thourough "How to" on that, along with decriptions of the fault etc.
I replaced my fuse box 18mnths ago, and no more problems. Instant fix.
It really is a VERY frustrating fault that is easy to cure but costs $ in a new fuse box/PDM.

Hope this helps?
Al.

 

I appreciate all the feedback! I will pick up the fuse box today and let you know...keeping my fingers crossed!