My 05 equinox ac works fine at fan speed 1 and 2. When I switch to speed 3 the fan keeps blowing but the ac light goes off. The fan still blows at 4 I think. The compressor is off at 3-4. Is this a typical blower resistor issue? It’s easy enough to change resistor. Could it be hvac control? It is not auto control. Just basic system.
I would pull the resistor and check the pigtail, the plug could be burnt, if so replace both…
I also would check the blower motor plug for the same thing…
I only had a bad blower motor resistor on one occasion, many years ago, and the symptom was that the blower would work on only the highest speed. As soon as I mentioned this to my mechanic, his instant diagnosis was a bad blower motor resistor, and it turned out that he was right.
Sounds like an open circuit in the blower switch/control panel. The compressor circuit is sometimes routed through the blower switch so that “OFF” on the blower switch shuts off both the fan and compressor.
I had similar issues with my 07 Silverado. The resistor was actually OK, but the main power wire to the resistor had melted along with the two wires next to it. I replaced the resistor and the pigtail but I am concerned that it won’t last. The wires that had melted their insulation were a heavier gauge than the wires that came with the pigtail. It has lasted about three years so far.
There are a couple of possibilities for the melted wires. One is that it’s just too hot in the area where the wires reside. Until you find the source of heat and deal with it, you could insulate the wires. The other is too much power going through the wires, causing excess power dissipation as heat and melting the insulation. You already dealt with that by using larger gauge wires.