Automotive Air Conditioning Information Forum (Archives)

ms4505 on Mon September 01, 2014 8:14 PM

Year: 2003
Make: Mazda
Model: Protege5
Engine Size: 2.0L

With fan on "1" the AC and blower work. AC light is on, compressor is working, and air is cold. Fan blows slowly.

Moving fan speed to 2+ the blower works (fan increases speed) but AC stops working (AC light goes out, compressor shuts off). Cycling the AC button does nothing.

Dropping fan speed back to "1" causes the AC light to come back on and all works fine as long as fan is on "1".
Unfortunately, this low of fan speed doesn't cool the car well in 97 degree summer.

PS: Replacing the blower motor resistor didn't solve anything. Did that based on bum advice.

Thanks in advance for your help and sorry if this is covered elsewhere in the forum. I couldn't pull up anything in search.

GM Tech on Mon September 01, 2014 8:27 PM

Is one of your choices in the fan selection speeds "off"

If so, your fan speed is the master on/off switch for the a/c compressor- and is wired in series with the a/c light- so I'd suggest, that the fan speed selector switch has bad connection on any speed other than "1" and needs replaced.

-------------------------
The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

mk378 on Mon September 01, 2014 8:31 PM

It's probably the blower switch. In the old-fashioned resistor/switch systems, the switch usually has a separate circuit dedicated to enable the compressor on any setting other than off. Also it could be a bad ground.

A bad resistor will not run the blower on low but it will work on high, so that was bad advice.

Edited: Mon September 01, 2014 at 8:32 PM by mk378

ms4505 on Mon September 01, 2014 11:18 PM

Quote
Originally posted by: GM Tech
Is one of your choices in the fan selection speeds "off"

Yes it does.
Sounds like an easy enough fix. We'll see how easy it is when I start into the dash.


Edited: Mon September 01, 2014 at 11:18 PM by ms4505