Trailer light issues, help me not make it worse

[krindgen]

A few weeks ago I got an indication in the truck that there was an issue with the LH turn signal. That rear LED turn signal was not working. Without doing anything else (mistake) I ordered a new light. The trailer would still light up and I made a couple trips. Still got the indication int he cab. In the meantime while waiting for the new light, I took the old one out. So the trailer sat in the driveway with the two connectors hanging loose.

This morning I went out, popped the new light in, and now none of the lights work in the back. But I don't get the indication in the cab that the turn signal is not working. I've checked fuses and will check again.

I first plugged the trailer in without having it hitched. Then I put it on the ball. I've taken apart all of the connections around the license plate. I did see the little round red light flickering a little. Also noticed the right side light, turn signal, was working but real faint.

So I'm guessing the light wasn't the problem. I've put a meter on the truck side plug and the LH turn signal is getting power.

I've peered into the jointed tongue and everything seems OK.

I'm going to hook everything up and see if I'm getting power at the back - what I should have done first! I also see a connection on the trailer frame for the yellow (LH turn) wire behind the logo light. It's rusted and I may take that apart and brush it up thinking maybe it's not a good connection.

Anything else I should be checking???

I can't imagine what went so wrong in the time the trailer sat here in the driveway that's nothing's working now.

[krindgen]

Put it all back together and nothing's changed. Rear light works but no turn signal. Have the trailer light fault indication in the truck. I'm thinking of taking the tongue plug apart and tracing the yellow wire.

[grazingrhino]

I had a similar issue with the 618 that I had, and just had the same issue with my 721 that I bought last October. On mine the pins on the connector that the trailer plugs into on the vehicle were not making a good connection. I bent the plugs eve so slightly to increase the contact and it solved the problem both times. You can check it by having the turn signal on and having someone stand at the back of the trailer while you wiggle the plug around and push and pull on it slightly.

[FD209]

Not sure if you already checked it but make sure it’s grounded good at the light/trailer connection. You may need to remove to scrape a little paint or coating off behind the ground wire connectors at the back of the trailer.

[krindgen]

I'm hoping it's that ground back by the license plate. The screw was all corroded and may have lost contact with the trailer frame. That worries me going forward with this gatorhyde coating. The LH blade on the connector was bent out more than others. Maybe I should bend them all. Now the lights aren't working at all. I may have to take it for a spin. Thinking maybe the ball/hitch is corroded too.

[Tom Edwards]

The ball/hitch shouldn't make a difference, the ground is thru the white wire in the trailer to truck connection/connector. Everything should work WITHOUT the trailer hitched to the truck, and not even close to touching tongue to ball. Check grounds, all of them. When you turn on the left blinker, do any running lights slightly blink? If so it is a bad ground, and the turn signal is trying to ground thru the other lights.

[krindgen]

The ball/hitch shouldn't make a difference, the ground is thru the white wire in the trailer to truck connection/connector. Everything should work WITHOUT the trailer hitched to the truck, and not even close to touching tongue to ball. Check grounds, all of them. When you turn on the left blinker, do any running lights slightly blink? If so it is a bad ground, and the turn signal is trying to ground thru the other lights.

Yeah, noticed the running lights weren't as bright. When I was messing around in the back I noticed the little red running light blinking a bit as a moved the connections around. Right next to where all the ground are connected to the frame. I'm gonna take that ground apart and scrape the gatorhyde off and reconnect. The ground screw was really corroded so thinking there's no ground at that spot.

[krindgen]

Ground ire up at the tongue. I think it was the one attached to the bottom of the solenoid. I do need the tongue hooked up. I think it's because that ground wire is at the end of the tongue, with the joint in the middle. With no weight on the tongue the joint is like an open circuit.

[haus9393]

I’ve been battling mine but the right side for 2 years. I get the warning in my f150 90% of the time I hook up. It’s all grounding issues in my opinion. I got a new ball and it helped for a bit. I think a lot of it is in my safety chains also and I have the bed liner under coating under my truck so that probably affects it as well.

[neo]

Take a pair of jumper cables or simular clip one end to the ground wire (white) from the actuator take the other end and find a good spot to ground to on your truck, then test.
That should tell you if its a ground fault problem.

[john721]

I unhooked the white ground ran it back to the marker light ground haven’t had a issue since

[krindgen]

Couple things I see. One being the gatorhyde. Some of the grounds are attached to the frame with clips on top of the gatorhyde. So the ground has to go through the threads instead through the clip. After the threads get corroded, and everything I took apart was rusted, the ground path is lost. I scraped away the gatorhyde and reattached everything and coated everything with the liquid electrical tape. I worry about the trailer rusting underneath the gatorhyde. I have a couple nicks in the bottom of the cross members I noticed today.

[Moneyshot]

My trailer will definitely not light without it being hitched and at least one safety cable hooked up. It seems as if my issues always come through the cables. I have new ones ordered.

[krindgen]

My trailer will definitely not light without it being hitched and at least one safety cable hooked up. It seems as if my issues always come through the cables. I have new ones ordered.

My experience too. I also see that my harness on the trailer tongue, the spring wound black cable goes tot he connector, is all cracked and open from the sun I guess. One more reason to build a garage.

[fishin couillon]

is all cracked and open from the sun I guess. One more reason to build a garage.

Garage wont help but a great excuse to build one .......mine stays in my closed up shop and it still cracked and peeled.....replaced it a about year or so ago......

[krindgen]

Garage wont help but a great excuse to build one .......mine stays in my closed up shop and it still cracked and peeled.....replaced it a about year or so ago......

Tit's all about rationalization.

[BroWhoop]

First I ran a ground from the connector wiring to the trailer, no lights flickering or any issue. When troubling shooting vdc wiring get test light. It's much easier to diagnose with it than a volt meter. I've been using meters all of my life on everything from milliamp circuits to 480 volts. 12 vdc is easier with a test light. There are times for a meter but on a trailer I'll take the test light 10 to 1 over meter. Plus find the problems easier.