Question about tow lights not working

My tow lights aren't working when i connect my trailer. They have never worked since i got the 4Runner used. I checked the fuses and they're all working. There is some sort of wiring harness near the hitch. I disconnected the wiring harness to look for any damage or dirt build up but it looks clean. I used my circuit tester to see if there was any power coming directly from the car, but got nothing. I don't know what else to look for to determine where the issue may be. At this point, I'm assuming there is damage to the wiring within the car that I can't access. Where I live, my 4runner is only worth about $2000 and I'd rather not spend an arm and a leg getting this issue fixed if possible. Any help is much appreciated!!

 

I’m no pro but I’d start figuring out where the wiring was run when it was installed and try to get eyes on as much of it as I can.

 

Did you use an actual meter to test for voltage at the connector?

You should only have voltage on one of the four prongs when the lights are on. One is ground, the other two are for the blinkers/brake lights. Make sure to check it against the frame of the vehicle, not just the ground prong on the connector because if you have a bad ground you won't get a reading.

Usually, if nothing is working, I would check for a bad ground at the vehicle connector, and also a bad ground on the trailer first.

 

i started removing the side panels from the rear to get visibility to the wiring but i was quickly discouraged as nothing was obviously damaged and i didn't feel like i'd be able to fully remove the panel without breaking the plastic, which i started doing....

 

I just used a circuit tester like this one: https://www.autozone.com/test-scan-...er/1330670_0_0?spps.s=2802&new_store_set=true

I checked it against the frame of the vehicle and none of the prongs gave any indication there was power.

 

So where are you located that a 4th Gen is only worth $2000, and what year and engine do you have, 4WD or 2WD???

Unless your 4th Gen has 300,000 miles or more runs badly and has a totally rusted out frame, it's worth more than $2000

So you're using a "test light" to test for power, have you tested your test light at the battery to make sure the bulb is not burned out?

 

I live in bend Oregon. It’s 3.4L 2wd and 235,000 miles. If it’s not 4wd, no one wants it here sadly. I know the bulb on my tool works as I used it to check fuses.

 

I guess all you can do is follow the wiring and look for damage.

 

First an obvious checkpoint, do your brake and turn signal lights on the vehicle work?

I agree, verify grounds first. You'd need a DVM capable of measuring resistance, maybe a local mechanic can help you out with this tool.

Ensure the connector pins are not corroded.

Verify you have a good ground to frame (follow/check the negative battery cable in the engine compartment.)

A 'light' indicator may not tell you the whole story. There could be voltage present but due to voltage drops across 'poor' connections along the way may not be enough to illuminate said bulb indicator on your tool.

 

I took it to the shop and they traced the wires back all the way from the tail to the front. They couldn't find anything. They said they'd need to disassemble the entire wiring harness up front which would take hours. Instead, he's charging me $600 for all the labor they did searching the thing and he's going to add wiring from the fusebox to the tail so i can at least have working tow lights. I am selling this fucking car as soon as i possibly can.

 

Welcome to the forum from North Carolina.

Sounds like you have a plan of attack, Improvise, adapt, overcome.