Trouble with tail lights not working in 89 Chevy S10, please read on for more detail...help

Question

There are no tail lights at all when the headlights are on. When I give a signal, both sides blink very dim. Also when I hit the brake lights, while the signal lights are on, they come on very dimly. When I hit the brakes, both tail light blink on & off slowly (when signal light is on). No fuses or bulbs are blown. What could be causing this?

Answer 1

Almost certainly a ground problem, especially for the latter symptoms. Check underneath for a ground strap that goes from the bed to the frame that's broken, or is rusty or loose at one end or the other. As far as the first problem, if your front marker lights work OK, it's probably the same reason for all of it.

The other possibility is that the wiring to all that stuff was damaged, like being melted by a tailpipe, or somebody doing a poor job of installing some trailer lights, and they're all shorting out against each other. But check the ground connection first, it's very common on pickups with frame on body construction.

Answer 2

the whole thing sounds like you have a lot of bad grounding connections. On an 89 chevy the cars were still made out of steel. Consequently all the grounding was done on the frame of the vehicle.

(todays cars have a lot of plastic so they use more wires now).

The car probably has rust where the grounds are connected.

Get a spray can of wd40 and spray all the connecting points for the grounds. I know that this is just a temporary measure but it helps to locate the problem points that u can either sand down or add ground wires to,