My teenage son has a 1987 Mazda B2000 pickup. It recently developed a problem with the A/C. Starting at the fan speed in the off position and the A/C dash buton pushed "On": turn the fan speed up 1 notch. A/C compressor turns on, but fan doesn't run. Turn fan speed up to the next notch, AC compressor still on, still no fan. Turn fan speed up one more notch, fan comes on but A/C compressor turns OFF! Turn up one more notch (high speed), fan runs but A/C is still off. I replaced thefan speed controller switch (the switch attached to the dash ****)but it still does the exact same thing...so I'm assuming the problem isn't in fan speed switch. What else could make the fan not run on 2 notches, and the A/C not run on 2 notches??? Any help anyone could give would be GREATLY appreciated! Thanks.

 

There's a resistor pack under the dash, attached to the evaporator box.

 

Thanks. I'd have never guessed that one. I'll pick one up tomorrow!

 

also sounds like freaon might be low

 

Refrigerant amount will not affect blower fan off/on/speeds.

 

I have a similar problem. I have a 2002 Protege5. My problem is as follows:
AC Switch on, Fan setting 1: AC and fan work
AC switch on, Fan setting 2: Fan works, AC does not.
AC switch on, Fan setting 3: Fan works, AC does not.
AC switch on, Fan setting 4: AC and fan work.

The AC used to work on fan setting 2, though it would take several minutes of the car running before the AC would start working. The problem has gotten worse over time. Sometimes I can make the AC and fan work concurrently by carefully turning the fan **** to a spot between settings (ie, between 2 and 3).

After taking apart the control unit and re-connecting the switches to the AC and fan switches the problem was remedied... for about a day and a half.

 

I have a 1992 b2200 carb.If I have my fan in position 1 the fan and a/c work.If I move the switch to 2,3.ect.. the fan keeps running but the compressor turns off.Sound like we all have the same problem.
Has anyone found the answer yet?

THANKS
JOEY

 

There's a resistor pack under the dash, attached to the evaporator box.

I posted this above.

 

Are you talking about the blower motor resistor?It is the only resistor I can find on a parts list.

http://www.autozone.com/autozone/cat...hText=resistor

 

Yep. From others here I learned that these go bad sometimes. I'm still on my original.