Im looking at purchasing a 2004 C5 that the owner says the headlights & windshield wipers don't work, he said fuses are good, Does anyone have any w=experience with this issue?

 

No I don't have any experience with that. But welcome to the forums. I would first Google the car, year and issue to see what pops up. YouTube might be your best friend on this subject. But right off hand if the fuses are good then its off to wiring, power, grounds, relays, and modules. When checking the fuses check for voltage at the fuses, and check voltage at all fuses, this would be a good start. I'm thinking wipers and lights are closely related to the power source for some reason. Research is going to be the answer, I will look around a bit and see what I can find out.

 

On the C-5s there are drains in the cowling that can get plugged with leaves and debree then back up water around the wiper motor and submerge it. Might be a good idea to check the condition of the motor.

 

If the fuses are good but both the headlights and windshield wipers don’t work on a 2004 C5, the most likely causes are a bad relay, a faulty multifunction switch, or a grounding issue. It is also possible the body control module or its connections are failing. Check the relays and grounds first as they are common points of failure for both systems.