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1993 MX-3
The vent fan only comes on in position "4"
I have checked the voltage to the fan and the voltage readout confirms that the
blower is getting around 12-13 volts in "4" but next to nothing in any other position
(like 3 volts in any other).

If you turn on the AC, the light for AC will only come on in positions "1,2,3"
If you put it to position "4" the AC light goes out. As above, the fan will only come on in "4."

I was reading a earlier post that someone thought it would have to do with the fan switch in the control cluster. I pulled the entire instrument panel and swapped the fan switch out for another one and this one is doing the exact same thing!

I can't see anything on these switches that would look like it contains resistors which could be bad, it looks like a simple switch board. Plus I already swapped it out. Has anyone else had this issue or an idea where else I could check?

It seems to me that the problem may be further down the line from the switch. Somewhere between the switch and the fan.


Thanks.

GRX

Here's the wiring diagram for 93 AC controls -
http://img150.imageshack.us/img150/9364/1993acsq7.jpg" onclick="window.open(this.href);return false;

Thanks, found it.

Bad soldier connection on the ceramic resistor.
Well, least it doesn't have to be replaced.

usually when this happens its the thermal fuse that burns up or the solders to it.