• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

91' No lights or power to rear of truck


Aaron285

Well-Known Member
Joined
Nov 16, 2017
Messages
108
City
Boynton Beach, FL
Vehicle Year
1989
Transmission
Manual
I have no tail lights, blinkers, or backup lights. Head lights and everything works up front except blinkers. Where should I start testing for voltage?
 
The rear taillamp harness connector.
 
So. Disconnect the harness, turn on lights and test DC, ground to each pin?
Big mistake people make when testing lighting circuits is to unplug the wiring. Try to back probe the connectors leaving everything connected. If you have a poor connection somewhere, it will support the current draw of the meter and give you a false reading. But the poor connection will not support the current draw of all the lights, so then the voltage drops. You want to put the meter in the circuit with the bulb load present. Another alternative to that is to use a testlight. The light in the testlight will draw enough current that the poor connection will not support it and won't make it burn bright.

The most common spot for wiring problems in the rear is a previous owners trailer plug wiring. They usually do not have very good wiring practices and it's pretty wet and dirty back there. Check for any trailer wiring first.
 
check the fuses.
 
I checked them. All good. I have 12v at the pedal switch to ground. I jumped to the back of the truck after that quick test and didn't see a ground wire. Where is it located? I have to check voltage and the plug from frame rail to harness to tail lights. I will test with the harness/ plug attached. Should I test pin to pin or pin to ground, and what color wire(s) and voltage and I'm looking for when pedal is pressed, lights on, etc.
 
Follow the wire looms from each light to the connector, you should have a ground wire come out of the loom to the frame or body crossmember. If it goes to the bed crossmember then check the bed for another ground connection to the frame.

Don't forget the license plate lights also. Do you have a trailer harness on the truck also?
 

Sponsored Ad


Sponsored Ad

TRS Events

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Ranger Adventure Video

TRS Merchandise

Follow TRS On Instagram

TRS Sponsors


Sponsored Ad


Sponsored Ad


Amazon Deals

Sponsored Ad

Back
Top