My 99 Jimmy SLT will not illuminate the license plate lamps at night unless the trailer harness is plugged into a trailer.

Just recently, possibly due to the crappy Wisconsin weather, my right turn signal blinks really fast. On the tail light, the top bulb illuminates, but the next one down doesnt. Here's the kicker...that second bulb down will illuminate when I press the brakes.

Where should I start with these two, is the ground located in the same place where the trailer wiring is?

I also have a "t-one" connector like this.....

http://www.hitchcorner.com/t1conect.gif

not the same female connectors on it, but will it work on the Jimmy? I bought it for a Chevy S10, 95' and it plugged right in.

Thanks guys

 

Start with replacing the bulb that does not blink, when it is flashing fast means bulb is burnt out.

 

I already swapped it with a good bulb and it still did the same thing. If it was burned out, it wouldn't illuminate when the brake comes on, which it does. Possibly a bad ground?

 

You might have two problems going on back there. For the tail light, it could be a bad ground in the socket, (which requires a new socket). The license light definitely sounds like a bad ground, or shorting out with the trailer wiring.

EDIT: Little trick from way back..... turn on the parking lights and the 4 way flashers. Watch the lights in back, you can usually see which one is messed up by comparing it to the other side, gotta blink in sync.