When I turn the A/C and blower on I get no blower operation on high. Low, med.low, med.high work but no High. I have an 87T/A with electronic heat controls. I was told there is a difference between that and manual. What do I look for? I tested power to the red wire at the relay and get power. Thanks.

 

Test for power while the blower switch is in high and everything is hooked up normally. I'd bet it won't be there.

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"So many Mustangs, so little time..."
ICON Motorsports

 

so what are you trying to say is that the switch is bad??

 

Usually the connector in the red wire that feeds battery to the relay burns up.

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"So many Mustangs, so little time..."
ICON Motorsports

 

I have checked old posts regarding that and I have power in and out of that connector. Last night after removing the connector from the relay and plugging it back in I got high fan and low fan but no between settings. I will order a relay today and see if that solves the problem.

 

Check the blower resistor pack. Its mounted atop the evaperator case (Has like 4 wires or so coming out) unplug it and with a 7mm wrench take it out and check to make sure it isn't broken.

 

I checked the resistor pack and it isn't bad but I picked up another one from my parts car and no changes. This is driving me nuts I cant seem to find the problem. I guess I will go to the dealer and order a new switch and start replacing from there.