Tail Lights Acting Funny

[ezroder83]

I have a 97 GMC Z-71 with the towing package and when i turn on either one of my blinkers it works fine until i hit the brakes and then the opposite tail light begins to flash rapidly. Also sometimes my tail lights do not work at all but if I go and wiggle the t-block around they will then turn on. Any ideas?

[VMax2007]

Check your grounds.

[bigredmariner]

Check your grounds.

 

+1 and Welcome to the forum.

[bill190]

What is a "t-block"?

 

If it is the connection for the trailer jack wiring and this is outside under the truck, I would disconnect it and clean the connections.

 

Does the flashing opposite light problem happen when a trailer is connected or without a trailer connected?

 

This could be improper trailer wiring if a trailer connected. Then I'm not familiar with your specific model, but in some models there is switching which occurs in the brake switch (When brake pedal is pressed.) This switching turns off a connection at the same time it connects another connection.

 

Also there is switching on some models in the turn signal switch for the brake lights and the hazard lights are related to this. So check your hazard lights to see if they are working for additional clues to this problem.

 

Most likely this type of problem would be mis-wiring of add on stuff (like add-on non-factory trailer wiring). Or mis-wired trailer. Or dirty mud caked connector(s) under vehicle.

 

If these things are not the problem and it is something wrong with the factory wiring or switches, I would not be able to find the problem without a factory wiring diagram.

[ezroder83]

I have a 97 GMC Z-71 with the towing package and when i turn on either one of my blinkers it works fine until i hit the brakes and then the opposite tail light begins to flash rapidly. Also sometimes my tail lights do not work at all but if I go and wiggle the t-block around they will then turn on. Any ideas?

 

Turns out it was the ground thanks guys. I had been messing with that for a week and completely over looked the ground I guess. Anyways thanks again.