Where do I start

[bertro]

Hello again,
I reworked left backup and tail/stop lights on our 71 safari.The light sockets were shot so I mounted new sockets to a piece of angle and fastened to the back of can w/self tappers.There should not be a ground issue,All wire reconnected the same.2002 suburban w/factory 7 wire.I reworked harness twice,I found male trailer chart on search engine here but no luck with this one.No tail or marker lights,left signal works,right signal blinks the left back up light,left brake light works,emergency flashers light both left lights.I dont know about brakes.Also what is the plastic bulb like thing that is in the center back of the can housed in rubber.If there is a bad bulb anywhere on marker lights will that keep good ones from working.
To many irons in the fire,Thanks

[Ganglin]

One item at a time or you won't get the help you need. If your working with connections from the tow vehicle first - lets get an electronic spray cleaner and treat both ends of the cable (auto parts store). Wiggle the connections after treating.

See what that does first. One bad bulb in a marker will not impact the others.

[LI Pets]

I assume you found the 12V fuse panel.

Even if the fudes are good the voltage may not go thru, test that with a voltmeter (multitester) and spray all that up also.

Then test with the meter

[peegreen]

Originally Posted by bertro

Also what is the plastic bulb like thing that is in the center back of the can housed in rubber.If there is a bad bulb anywhere on marker lights will that keep good ones from working.
To many irons in the fire,Thanks

There is a fiber optic that will transmit the light from the brake/turn/tail to an indicator on the streetside of the trailer. The driver can use the side view mirror to check that the lights are energizing. The indicator is a small white plastic housing protruding from the side of the trailer towards the rear. The indicator moved forward with newer, uh, mid '70's. A marker lamp that is not working will not affect the function of any other lamp - not like old Christmas lights.

[PizzaChop]

Most wiring issues can be addressed with a 12v test light and a lot of patience.

In some cases, it may even be necessary to rearrange wires in the plug. Your back-up light working with the blinker makes me suspect you may have this problem.

Start at the beginning (TV) and work your way back. (I wish I could remember the colors now, as I just did this on my Sovereign not too long ago. I think green is tail lights, brown is left, and red is right, black is back-up, blue is 12v, white is ground, and I can't remember brakes)

Unplug the umbilical cord at the trailer end and check each circuit to make sure you have voltage through the cord.

Next, remove the 12volt cover at the front wall of the trailer (backside of the umbilical cord). The big red wire in the center is your 12v from TV. The big white is ground, the green is tail lights/running lights, brown is left, red is right (or vise versa), yellow is brakes (I think), black is back-up.

(You can verify all of this yourself with a test light!)

I would be very suspect of your ground on the tail lights because of how much trouble I've had with them myself. I finally removed the housings on this one and replaced all four cans. Best thing I ever did. I drilled a 1/2" hole in the back for the fiber optics. (I also replaced every single running light, 5 red, 7 amber, $1.99 a piece at a trucking supply place). Anyway, a bad ground will really mess with your mind!

When I finished, everything (I mean everything) worked perfectly!!

If you're patient and work methodically, you'll get it!



H