Hi, I have a 91 B2200 carbureted. I bought it recently and notice that the fan blower will only work on the highest setting. Whenever I turn on the A/C, it will not blow cold air when I turn the fan on (position 4). However, if I turn the fan to position 1-3, I will hear the compressor kick on and the idle will drop. If I move it back to 4, the fan will be blowing cold air for about 45 seconds. Basically, what I have to do is flip the fan switch back & forth to manually cycle the compressor. I believe this problem might be linked to the fan speed resistor. I have found those on ebaymotors, however, where is it located, and how hard is it to get to? If replacing that doesn't solve the problem, how can I get the A/C to function correctly? Any help is appreciated.

 

Yes, sounds like a fan resistor issue. The resistor pack is on the outside of the evaporator box, under the dashboard. Take out the glove box to see.

The switch with two wires on the evap housing and a sensing lead is the de-icer thermostat for the evaporator.

 

Thanks for the advice. Ordered a new blower motor resistor for $30, and found the old one behind the glove box. Sure enough, the coils were busted. Put the new one in and I have air conditioning in all 4 fan positions. My friend has A/C gauges, so we hooked those up and I'm good on refrigerant. Thanks again!