GMC Repair: backup lights, gmc sonoma, lighting work

Question
QUESTION: OK the backup lights in my 2002 GMC sonoma flicker but mostly do not work. I checked the fuses they were ok. Then I checked the bulbs, and they were ok. Everything is pointing at a possible short, but all the other types of lighting work. What would be the easiest way to resolve this issue with my backup (reverse lights)?

ANSWER: Hi
Standard trans or automatic?????
Pawl

---------- FOLLOW-UP ----------

QUESTION: OK the backup lights in my 2002 GMC sonoma flicker but mostly do not work. I checked the fuses they were ok. Then I checked the bulbs, and they were ok. Everything is pointing at a possible short, but all the other types of lighting work. What would be the easiest way to resolve this issue with my backup (reverse lights)? its a standard tranny.

Answer
Hi
I would check the reverse lamp switch, located in the side of the tranny.
It is a small switch with 2 wires.
You can jump it with a fused jumper and see if they on steady. This will also check the integurity of all the related wiring.
If do not flicker with switch jumpered, I would suspect high resistance in the switch.
I hope this helps.
Follow back post, if needed.
Pawl