A/C won't turn off. Stuck on full blast
 

Over the weekend, my A/C was set on number 3. Its the manual kind. While driving it just stopped blowing. I moved the knob and it came back on. A little while later it went to full blast and I couldnt turn it off. Even when I manually put the knob in the off position.

I unplugged and removed the blower resistor and it made no difference. Only way to get the A/C to stop was to turn the car off. I still have full control over the temp controls.

I took out the Climate Control unit and unplugged it from the back. This stopped the A/C from blowing. When I plugged it back in, it went back to full blast and I was not able to control it.

When I took the CC unit out, the part behind the manual control knob was BLAZING hot, as was that long connector that I unplugged.

Is the CC unit my problem?

Thanks,
Matt

The switch may have shorted out. Check continuity with a multi meter.

Not big into electrical stuff, though I have a multi meter. Where is this switch that should be checked?

Prefacing this with the confession of having next to NO knowledge on AC dash components and stuff. However I did read somewhere way back in the day that the AC fan's natural state is full blast, and that somewhere in the electronics it uses resistors to make the settings 1,2,3. That coupled with the fact that you can't turn it off leads me to believe what NJmax said to check the switch controlling the different states.

As far as the location, I don't have my FSM PDF on my work machine but I know you can find it from Boredmder

yeah, I have a copy of the FSM. I'll try to find it in there.

The fan switch bypasses the resistor for high speed, so you can unplug/remove the resistor and the fan keeps running. If the fan shorts out internally, you will get the situation that you have.

The fan switch is part number 27660-65E00, List price $48.32, on-line $36.44 + shipping, which may make about the same price. I don't know if you can get the switch at auto part stores or not.

http://www.nissanpartszone.com/Page_...mponentsNo=272

yeah, I looked at that diagram and that fan switch is the part that was incredibly hot. It would have burned my finger. Thank you!!