Hi, I've done quite a bit of searching for this issue and it seems some people have somewhat common issues as I am. I've got an 89 pickup 4x4, and a few months ago my left taillight stopped working. The brake light, indicator, and reverse light still works. The right taillight works as it should. Fuses are all good. I thought maybe it was a bad ground, so I put the volt meter to the socket to test for voltage, but didn't get anything. I should mention that the bulb is fine as well. Is there anything else I should be checking for? I'm puzzled. Thanks!

 

Socket corroded ??

Physical damage to the wire for the tail light circuit

Your sure the bulb is good and the correct one??

 

Thanks for the reply Wyoming,
The socket is rusted on the outside, but the inside doesn't have any corrosion. I also made sure it's an 1157 however there is definitely damage to the circuit under closer inspection. The trailer harness has been sloppily installed, and there are a number of wires that have been cut- one being the tail light wire. Of course I can't get a reliable wiring diagram for this year either! So I'll have to get back under it after work today with my test light... I'll make a post if I solve it

 

Do yourself a favor get yourself a multi meter and don`t look back.

I would venture I have not used a test light in 30 years .

The second color is the stripe!!

White/black is the ground

Tail lights and marker lights should be green with license plate lights green/blue

brake lights are green/white

left turn is green /black

right turn is green/ yellow

back up lights red/black