Trailer wiring HELP needed.

[LHaven]

Test continuity between brown (3) at the end of your plug and brown in the junction box to see if you have a bad cable.

If you have continuity, switch to volts, plug into the truck, put the running lights on, and check for 12V on brown in the junction box. If you don't have it, check to see if you are parked on an Indian gravesite. If you do, check for rat chews downstream in the trailer.

[rev500ss]

Back again and still no change.
Checked ALL connections for continuity and everything is good. Checked my truck again with my digital clamp meter and everything is good there just like my tester said. I'm ready to give up

[Steveo57]

If your truck is testing good and you were able to get all the lights working by connecting power to them at the junction box then I believe the only thing left is the cable and plug from the truck to the junction box. Have you checked continuity or voltage on each wire coming from the truck to the junction box?

[rev500ss]

I just check all wires going from the 7pin male end to the junction box on my trailer and continuity was good.
I re checked the truck end just to be sure and it was still good.

The male end was also replaced last year when I first got the trailer. All wires have been removed, terminals cleaned and re assembled in the last 2 days.

Again this whole package worked in May when I brought the trailer home. Nothing has changed between then and now. The trailer has been in my driveway since May.

[LHaven]

Continuity is fine, but nothing says "working" like lights going lighty.

I'd still hang a temporary wire from battery +, then touch it to 1) the brown junction in the junction box, then 2) pin 3 of the trailer cable, and see which, if either, make the running lights light up. It beats shotgunning the problem.

[Steveo57]

If your plug is wired like the diagram John provided earlier I would take a jumper from battery - to pin 1 on the trailer plug, Then a jumper from battery + to each of the other pins and verify the corresponding lights come on. That would eliminate the trailer.

[Pinto]

IMO you have a bad ground somewhere. That is the only common thing to all connections.

[wiredgeorge]

Originally Posted by rjniles

Buy a 7 pin test light from Walmart and check to see if the truck wiring is working.

https://www.walmart.com/ip/Truck-Tra...EaAoDNEALw_wcB

You owe me $11!!! That is a neat tester and I couldn't resist when I saw the darn thing and bought it on my wife's account! YOU ARE AT FAULT!!!

[Hamlej]

Not sure if you have a single battery or multiple batteries set up. Are they connected properly? While installing the battery if reverse connected you will blow the fuses in your electrical panel thus having no 12v power.

[Callie Spillane]

Hi, It may be your negative wire to the frame either on the plug or the trailer that is missing or not hooked up. With out that wire nothing will work.

[RobSwaney]

take a booster cable attach to truck frame and then to trailer frame. Make sure connection is good and clean no paint. Check you lights and see if they are coming on. Lots of time it will test fine and then when you put a load on the ground will go away.

[rev500ss]

Hi folks, back again after testing, more testing and even more testing. I tried everything everyone suggested and still nothing.
Fast forward to yesterday, I ordered a new harness, plug and junction box. Amazon shipped to my door and after finishing work within about 20 min my lights were going lighty! My brakes were making noise so (haven't road tested) my brakes were braking!
I really don't know what it was, but I'm glad I got it sorted out!
Thanks again for all the help and suggestions.
Greatly appreciated.