This is the story as it goes.

1996 or 1997 ram 2500 , v10 gas , auto , blah blah... with a 20' tag car hauler.

It is our service truck at work, they recently bought a 12 000 lb warn winch for our trailer, and i got the job of mounting it. I fabbed up some nice heavy duty mounts and bolted it down. For power we put a truck battery on the front of the trailer and wired the winch to that.

For charging the battery from the truck i used the red wire w/white stripe (had constant 12v , almost 14 when the truck was running) that was hooked to nothing , i assumed it was for charging RV batteries. i wired it through the center pin on the 7 pin RV harness , it was unused.

Now we only have park/driving lights on the truck/trailer. No turn signals , 4 ways , or brake lights..

this problem was discovered several days after the wire hookup was complete.

Even with the trailer unhooked still no lights on the truck.

Relays and fuses under the hood all appear fine. in the fuse block in the cab , the fuse for turn signals and the fuse for brake lights were both blown, replaced them , STILL no lights , and the fuses did not blow again..

A little more history, a couple weeks ago the dash was apart in the truck because the high beam indiacator was not working. I know at least the turn signals worked since then , because when i was doing the wiring i used my test light on the 7 pin plug to see what contacts were unused.

As far as troubleshooting i have power all the way to both the brake and turn signal fuses , and the fuses are good. makes no difference if the trailer is connected to the truck or not, there is still no turn signals , 4 ways , or brake lights.

What the heck can i check next

 

Did you check the bulbs?

 

NO i did not , but here is why... if all the bulbs are burnt out in the trailer and in the truck, would the indiactors on the dash still work? Because they do not. The 3rd brake light does not function either.

I just find it very highly unlikely that every blub could be blown , and if they were , something caused it.

 

How about the flashers that plug into the fuse box?
Therrs one for the 4 ways and one for the turn signals I believe.

 

Id say check your fuses..

If you are overloading the little fuse that blows, IE trailer lamps, replace it, check under the engine power pack, i dont member what color it is, or anything like that though, but i know its there, if that fails try engine control, man thats a tough one u got..

Tx

 

The fuses in the dash are both good , i put new ones in , and they did not blow again , the fuse the the power center under he hood is also fine , all of them , i tried swapping relays with ones that i knew worked , and no change.

I have constant 12v to the fuses in the cab, so the problem is downstream from there, the problem , is i don't know whats downstream , between that fuse and the actual lights , what is inbetween? multifunction switch , but why would it take out brake lights...

A service manual would help me greatly , but they will not spring for one at work. Even just a wiring diagram would help immensly.

I just don't know what is common between the stop lights and the turn signals, it is something common to both of them. I thought about a ground , but why would that blow fuses , and the park lights wouldn't work if there was a bad ground , i don't think.

 

Did you check the the turn signal switch wiring and the harness for the 4 way flashers. You said someone had the dash apart previously, maybe the 2 incidents have nothing to do with each other.
Also is the 7 way connector factory installed or spliced in by the owner, I thought the factory tow package had relays to switch the loads.
If you use a test lead with a breaker inline, connect to the battery wire you are charging the trailer battery with and with the feee end, touch it to the stop, left and right terminals in the trailer socket and see if the lights work from here.
I think it might be in the turn signal or 4 way harness somewhere under the dash.
Something might have got pulled loose when the cluster was pulled out.
BTW did you take the 7 way recieptle apart? lots of wires to short out in there.
Good Luck. Jim

 

I would start the headlight sw. thatw the single most comin ckt. those lite are all on then go to the foasher relay for both the turn and 4way , but scince there both not working I would still lean torwds the begining of that ckt. , I've read that thats anouther weak point is the headlight sw. not hndling the load of the trailer.

 

Theheadlights , and park lights work , so i ruled out the headlight switch , and i think if the flashers were bad i would still have brake lights.

the 7 pin connector was origionaly on the truck , but it has been rewired and relocated since the shop took ownership of the truck. most wires were unused and actually not even wired to the 7 way , there was only 4 , maybe 5 wires inside the connector , on both ends.

I am leaning towards the multifunction switch myself, since i have heard that the brakelights are wired through it also. that would give me something common between everything. It may also solve the problem with the high beam indicator , which is why the dash was apart before.

 

Seeing as you are in Canada - If your daytime running light module has been disconnected your high beam indicator in the instrument cluster will not work. The daytime running light module is a square box located on the drivers side front fender. Do your daytime running lights work?

 

What we need is to be able to look over the posts so to be able to make particular comments Or at least I do!!!!!

First comment is that any company that won't buy a maintenance manual is Nuts!Far too expensive in wasted time!
Since you have access to the net try www.etrailer.com for trailer wiring they do have the 7 pin as well.
Sounds like you took out a switch somewhere, daytime running lights box. Lights would stay on if it was bad. sounds like you have a multi meter check voltages at the lights in the truck and on the pins for the trailer.
As for power for the winch 15,000 lb these will draw a lot of current probably (400 to 500 amps) so you would be better with the 2 plug for the winch.It is good that you have a battery there but it will need to be resupplied. You should put in an (isolator) by the batteries for mechanical isolation if it needs it. A fuse for that might be hard to guage. leave hood open when you use it and turn it off when you are done with it each time. I would put that clear hose over it for better protection.

 

The high beam indicator works sometimes , that's not the issue i am dealing with.

There is no voltage for any of the turn signals/flashers/brake lights anywhere, checking plugs will get me nowhere.


the multifuction switch is fine, all lights working momentarily , as soon as the trailer is connected BAM no lights.

What is the red wire w/white stripe for? where does it go?

 

If you want the wiring diagram for the trailer connections check this out:

http://dodgeram.info/tsb/1996/08-33-96.htm

 

OK, I had a problem like this on my new gooseneck trailer, the old one worked great on the truck, but when we put the new one on it burnt out the turn and running and stop lights. PROBLEM, more lights on the trailer, and the DODGE truck electrical is NOT set up for that amount of current through the turn switches, blinker unit and fuses.

After replacing several components (blinker unit, fuses, etc) ....... and getting the truck back to normal again...........

We did the following:

1. Made sure a #10 guage 12+ lead was installed on the 7 pin plug to the trailer. Fused it at the front fuse block (in engine compartment) with a good size fuse (30 amp)

2. Installed 2 relays, Bosch type (you can install the socket/relay combo or the relay with the mounting tab on it) , rated at 35 amps each. Contact pins are going to in line Fuses on the 12+ lead at about 15 amps each, and then to the appropriate turn signal lamp lines on the trailer. The coil side goes to the turn signal leads from the truck, and the other side to the negative.

3. Installed 2 relays, Bosch type, one to the Running lights on the trailer, and then fused to the constant 12+ lead (fuse 15 amps), the coil to the Running lamp lead on the truck. Second relay went to some backup lights we mounted on the trailer, and the relay went to the AUX lead on the truck connector.

You can put all these in a little waterproof box on the side of the trailer.

We now have full turn signal, running lights, stop, and backup lights, without burning out the trucks system. And it does not matter what truck is used to tow the trailer, as long as the truck supplies the 12+ lead, and uses the 7 pin connector it is the same.

One additional item, we bought the "charger unit" for the emergency break away trailer brakes battery. It goes on the 12+ lead and re-charges the break away battery as long as the truck is plugged into the trailer.

All above was not more than $100 bucks.