Climate control relay

SOURCE: Blower Motor problem

Hi,

Sorry but most that I can give would be generic as Pontiac Grand Prix are not that common in my country. I am assuming you are referring to the fan/blowers of the A/C unit.

Based on your description and from what little I know of the circuitry/wiring of current blowers:
1. the clicking sound would be a relay engaging and therefore the speed selector switch could be assumed to be operational since it can trigger the relay;
2. the day time running lights and auto night lights turning off when engaging the fan switch indicates possibly a common supply problem. This could be a wire or terminal in the fuse block. This common B+12 supply logically would be split into several including the fan blower fuse and the lights fuse. It is also possible that said terminal is corroded or has scorched marks preventing full flow of current or be disconnected intermittently;
3. since you have changed the resistor (presumably known and tested to be good) then the problem lies elsewhere possibly back to #2 above;
4. I would discount any ignition problem as it would be more engine related and has nothing to do with the fan/blower except that it share a common IGN B+12 which again points back to possibly #2; and
5. Though am not sure, but I think your car has also a blower motor control processor which also could be at fault.

I believe your best option would be to use a DVM to check for the presence of B+ supply to the fan motor while going through the switch settings (1 to 5). Thereafter trace back until you reach the resistor and its input of +12, go further back and trace it to the fuse holder and eventually to the common supply. You would have three (3) B+12, a) always ON; b) IGN ON; and blower switch ON.

Would appreciate a post back for any developments or results of your voltage checks.

Hope this be of initial help/idea. Again, pls post back how things turned up or should you need additional information.

Good luck and kind regards.

Thank you for using FixYa.

SOURCE: WON'T START..NEW BATTERY ..DEALER CANNOT DIAGNOSE

remove the sparkplugs and clean the heads with a wire brush and test to see if the gap is rite

SOURCE: Does volvo have a recall on ecc climate control for A/C SYSTEM (

I had this problem and this may or may not be the solution. For me it was the drain tube, it was plugged but draining just enough to not overflow onto the passengers feet (actually it did once). What I believe was happening was the fan was throwing water and shorting out the climate control sensor. Once I got the drain cleared and the water drained I have not had the problem since. Side note, I was able to shut the car off then turn it back on to reset the fan and make it run again. This may not be what you are experiencing but at least its something to think about and maybe it might help someone else.

SOURCE: 1999 BMW 328ic Climate Control Problem

There is a fix for this on the web. You have to remove the control unit and replace a resistor or capacitor. I did mine and it worked like a charm. Takes a coupla hours. the resistor is less than a dollar.

SOURCE: Climate control switch does not work in lower modes only in high.

The pontiacs have an issue with the ignition switch, I have a 2001 grand prix that did the same. The ac fan would only work on 5 and the headlights would go off if on 1-4 replace the switch and all is fine.

Testimonial: "Right on, found same info on Gran Prix forum with detailed instructions. Harness assy that is wiring&key switch coupling corroded."