Trailer harness from car acting up

[Raycaster]

Trailer lights are acting up and everything points to the trailer harness (uhaul install) being the culprit. Trailer wiring perfect but all I get is brake lights on 100%.

No running lights or signals.

Checked power to module fuse - good.

Checked ground - good.

My crappy Dodge Caravan 2012 lights work perfect and checked fuses.

The 3ft cable from module is not cut, checked at module and its not supplying signal lights etc.

 

While not an electrician I still consider myself pretty adept at electrical circuits and a 4 wire loom for a trailer isn’t rocket science.

I’m ready to just replace the module/harness and see CURT brands sold everywhere. Anyone have suggestions or something Im missing? As mentioned, the trailer is not in the equation, its not connected. The 4 wire connector has led indicators and they also show no signals.

 

 

[Terry]

If you have a meter check if there is power at each stage of the wiring 

if not take the bulb out of the tail light add a little piece of wire and test at the car and trailer to see what power is there 

[Wallyman]

Go around your trailer.  Loosen all ground wires and then tighten them back up.  Just a small bit of corrosion can make them act funny.

 

good luck.

[Wallyman]

Sorry my bad.  Did not read about the trailer not hooked up.  My other guess would be in the fuse panel.

 

Regards

[OhioFisherman]

https://www.curtmfg.com/part/56331

https://www.draw-tite.com/product/119178_taillight-converter

The bigger black object is the module? I am assuming it is your problem, on the Curt one the only review indicates a short lifespan? I don't see how power goes into it, but if it's working properly power should be coming out properly?

 

[Raycaster]

Just to clarify, the trailer is working 100%. The wire harness tapped into the vans electrical is the problem as it isnt providing proper voltage to the trailer.
 

The module is a basic relay setup avoiding any problems with trail light setup’s interfering with the cars electrical.

I know I should purchase a new wire connection module but my empty wallet is leaning towards just splicing into the old 2012 Caravan tail lights and making for a quick job 30 minute job. 

[Fisherman]

33 minutes ago, Raycaster said:

I know I should purchase a new wire connection module but my empty wallet is leaning towards just splicing into the old 2012 Caravan tail lights and making for a quick job 30 minute job. 

As long as you have brake and signal lights together on each side.  If you have separate brake and signal lights, it's either a module or 1 more light on each side.

[AKRISONER]

I think you’ve already answered your question yourself but it sounds like the connection on the van is the problem.

multimeter at the outlet is the easiest way to see what’s going on.

[OhioFisherman]

https://www.etrailer.com/question-96080.html

https://www.etrailer.com/t1-2012_Dodge_Grand+Caravan.htm

Top link gives an explanation on why the module - converter is there, seems to me I had a vehicle that used one.

 

 

 

 

 

 

 

 

 

 

 

 

[Fisherman]

57 minutes ago, OhioFisherman said:

https://www.etrailer.com/question-96080.https://www.etrailer.com/t1-2012_Dodge_Grand+Caravan.htm

Top link gives an explanation on why the module - converter is there, seems to me I had a vehicle that used one

My '78 Rabbit was like that, separate turn and brake lights.

[DanD]

If you have the 5 inputs (right & left turn, brake, tail lights and ground) going into the converter/module from the vehicle and not having the proper output signals. Then it has to be the module. Your next question should be why did the module take a dump? An intermittent connection on the trailer will take these boxes out every time. Even though you know the trailer lights all seem to work normally while you check them sitting still. Doesn't mean you don’t have an intermittent connection bouncing down the road. To try and check this you could try what Ford motor company still considers a viable test. They call it a wiggle test. LOL Turn your tail and brake lights on and literally wiggle and jiggle the wiring harness, connectors, where the harness goes into the light assembles and the actual bulbs. All the while watching if either of the bulbs flicker. Not saying that is what has happened to your rig; but it wouldn’t hurt to be sure it isn’t. 
 

Dan.