I'm in the process of checking out my newly purchased 2004 2500 CTD Ram.
I did a quick check of the factory wiring for the trailer lights and both the 7 pin plug at the bumper and the 4 wire pigtail on the harness.
On both I have no power for the right side turn signal/brake light.
All the tail lights and turn signals on the truck itself appear to be working properly.
I took the 7 pin plug at the bumper apart and it looked fine, no corrosion, but still no right side turn signal/brake light
In doing a search here I've notcied a number of people with similar problems needing a new power distribution box
So I guess i'm going to check this box out tomorrow.
Are there any fuses in this box or anywhere else?
Would there be a specific fuse just for the right side trailer lights?
If I need a power distribution box I see some are buying it and installing it themselves.
How difficult of an install is it?
Anyone have a part number?

Thanks.

 

There should be a fuse, usually in the engine compartment fuse block, that will be a fuse for the trailer right turn. This fuse is ONLY for the trailer wiring, which is why your truck's tail light still works.

 

i second that, if your trucks lights work, then the control module is fine, i just replaced mine to find out that i had a break in the wire just above the fuel tank, where you can get at it, unless you drop the tank. how i found my problem, is i did a volt test along the wire that i wasn't getting a full 12 volts to. just infront of the fuel tank was 12 volts, but just behind it and all the way back to the plug was 2 volts. so i spliced into that wire a new one, everything is good now. i had a couple wires that were broken in behind the drivers head light for some reason, might be a common problem, not sure, but it was my problem.check fuses, and buy good ones if replacing.

 

Yeah.... check the fuse in the box... if the fuse is good then ... yes... unfortunately it will be the box... I have gone through 2 boxes so far.... They are about $250-300 new... Last one I got was used for $25 at the junkyard... They are easy to install... Unplug the battery and then remove the PDB out and unplug the harnesses from the bottom... Plug them into the new one and reinstall....transfer fuses and your done...
I am thinking of making a relay box that plugs into the back of the bumper and uses the regular trailer wiring as a trigger for the relays... That way if you loan out your trailer and it comes back with a short like I did... You will only blow a fuse or relay and the PDB survives.

Oilguy

 

Thanks for the responses.

It must be my lucky day, after looking into it I found a blow fuse in the PDC.
I replaced the fuse and all apears to be working properly

 

There is a fuse. I have had the same problem.

 

So where did you find the blown fuse? I have a 2006 2500 with the same problem.only mine is left turn on the trailer only. Everything else on the truck and trailer works fine I have check the fuses in the power box but they appear to be OK. Any help would be great,

 

I know the OP has fixed his issue, but like others, it's not likely to be the last issue.

There are also relays in the PDB that, at least for the 03-05 trucks, are not serviceable. To correct, the entire box must be replaced at a ridiculously high cost. This past summer I also had a trailer light issue and traced it back to the box, but all fuses were good.

The fix? See here: http://www.etrailer.com/Wiring/Tow-Ready/119190KIT.html

This kit gets its trailer light signal from the truck's brake lights, but gets power from the truck's battery. Thus, no loss in juice which would result in a LAMP OUT message. AND it works perfectly.

Here's a thread of another member installing the Modulite:

https://www.dieseltruckresource.com/...light=modulite

 

I had the same problem with my 03. Read all the forums posts regarding that problem. Same answers regarding the fuse if not the Integrated Power Supply relays. Well I'm here to say the problem could lay in the factory wiring between the front of the truck IPS & the plugs in the back. I too checked the the wiring under the PDB as the whole thing unblots rather easy & you can pull the whole thing up. The plugs are all different so you can unplug them, remove the factory tape on the bottom of the connectors & check for burnt or corroded cables. If not you can pull the IPS & if so inclined you can take it apart & check for corrosion. Why not if you are going to replace it. I even checked the infamous relays under the board. Guess what they work. I purchased a used one for $250 here in Ontario. So someone before me hacked the wiring under the truck & put in a non powered modulite of some sort. I had no choice as the wiring from the IPS had been hack somewhere else as I said between the IPS & the connector split. So I put in a powered modulite as big as I could get which simulates what the truck would have if working. I put the IPS back together & coating the bottom of the board which is exposed a bit on the bottom & it works fine. I now have a $250 back up.