How do I troubleshoot blower switch relay problems in my car?

Answer by  bug57 (1048)

Obtain a electrical diagram for your car, and test for voltage on specified wires while operating the switch. Test the relay for continuity between ground and 12v- none should exist.

Answer by  hwht25 (441)

Well if the switch is not working properly, you can try rewiring it and see if it works. Just clean the part. Sometimes there is something clogged or jammed in there and that is why it is malfunctioning. Worst comes to worst you can just replace the parts as needed.

Answer by  kennethjgoodson (4903)

You are going to want to take a test light and make sure that in your fuse box you have power going to the relay. If you do you may want to replace the relay.

Answer by  Jenny30 (161)

Easiest way to see if you have a bad relay is to switch it out with a known good relay. IF that fixes your problem; then you have found that you had a bad relay. Otherwise test for resistance at blower switch to see if you have a bad switch.

Answer by  iowatech (78)

the resistor is most likely faulty. it is located by the firewall, at the front of the floor on the passenger side.

Answer by  doc325 (454)

You first have to obtain a wiring diagram for the circuit. Then just check for power at the blower when the switch is on the various positions.

Answer by  mb (5482)

You probably have either a hose connection problem in your car (just check the air hoses entering the dash from the engine side. Or you have an electrical problem that will need special diagnostic computers.

Answer by  japratt (1687)

When you are having relay problems within your car you will need to replace the switch and not worry about repairing.