AC/Heater fan only works on high fuses and relays are good thinking switch?

SOURCE: heater/ac only works on high...and on high it's extreamly noisy

Hi. If you haven't figured this out yet, the issue with the blower only working on high is caused by a faulty blower resistor module. You can get these from the dealer or NAPA. The issue with the loud noise is most likely caused by either bad bearings in the blower motor or the impeller (fan blade) on the motor. The resistor module will probably run you $40.00. The motor assembly, about $150.00.

SOURCE: Heater/AC blower will not operate

Replace the blower resistor.

SOURCE: 1983 Chevrolet Suburban Heater fan not working

check relay and blower resistor...likely the relay is bad.

Jun Magno

• 175 Answers
• Posted on Jun 02, 2009

SOURCE: Need Fuse Map Diagram BMW 318i 1993

check the internet for a bmw e36 ETM ( electronic troubleshooting manual) everything you need is there.

SOURCE: can some post the 1999 gmc sierra wiring diagram

you don't have enough pressure in your system. odds are you have a leak someplace and the factory installed a saftey switch to keep the ac from running when there is no pressure. This way you don't end up burning up your compressor.