Can someone smarter tell me whats going on with my 2002 Chevy Trailblazer LTZ 4.2l turning signals. So the problem is that all of the turn signals blink rapidly when turned on (hyperflashing is it?) but in the rear they blink very dim. When the truck is on, rear blinkers won't blink at all.
Hazards do work just fine. Also all the other rear lights work.

I have replaced the flasher relay, bulbs and the rear light circuit boards on both sides. Also I have cleaned the connectors and checked the fuses.

Could the problem be in grounding? I tried to google the locations of the right grounding points, but didn't find the right ones.

 

i would be incline to think it is a grounding issue. poor grounds can cause all sorts of weird issues. i cant say where theyre at on the trailblazer, so i cant help you there but i do believe youre on the right path

 

The tail light housings in the rear of these vehicles are not sealed too well. If moisture got in there, you could have a corrosion problem and all kinds of funky things can happen.

 

I used to have a 2003 Trailblazer and it had problems with the taillight assemblies. The bulbs kept burning out. Chevrolet had a recall on it and replaced both circuit boards and bulbs. It helped but still burned out bulbs occasionally.