I have a U.S. 2011 Volkswagen GTI. After the car wouldn't start (starter would crank but engine would not turn on) I decided it's probably time to replace the battery, and did.
Car starts fine, but now the AC blower won't turn on at any setting. All the normal AC lights come on on the dash, and I can hear the engine revs changing when the compressor kicks in, but no air comes from the vents at any of the 4 fan settings.
Here's what I've done so far
- Checked every single fuse (under the hood and under the dash) both visually and with a non-powered fuse checker.
- Disconnected the battery for about an hour and reconnected it (I read something online about allowing the system to reset, probably hogwash)
- Visually inspected the blower's resistor pack which is located under the passenger glove box. It appears OK but I'm not sure how to actually test it with my multimeter, or if I should even try at this point.
A couple other details:
- When I connected the new battery, the negative terminal arced upon connection. Could this indicate a bad ground somewhere else in the wiring?
- I have a custom stereo system with a 600W amp connected to the battery which has worked fine for a few years now.
- When I went for a drive earlier today, the windows would roll down but the automatic rolldown function (when pressing fully on the button) wouldn't work. When I started the car again later it worked again.
The above makes me suspect a bad ground, but I'm just now learning how to diagnose electrical problems! I'm a complete novice at maintaining my own vehicle but am eager to learn, especially since I'm now out of warranty :)
What steps would you take to diagnose this problem?