I checked the fuse and it's good. I try to turn on the a/c, heat, vent, defroster, etc. and no air comes out of the vents. The radiator electric fan turns on; but that's about it. I looked in my Haynes manual, but there isn't that much information on the a/c system. I figure since the heater doesn't work the problem isn't the a/c compressor. Is it a switch or a fan motor, etc.?

Any opinions would be greatly appreciated. OH, and please give information on where the culprit is. If it's a motor, where is it located. Pictures would be great, if possible. My thanks in advance.

 

Coach,

The blower requires a power source, a closed fan switch, an operating fan relay, a motor resistor, and a good motor.



You've already checked the fuse. We'll presume that the switch is O.K. for now since it is the most difficult component to access. The next item is the blower relay. This relay has a normally closed pair of contacts that supply power in the three lower blower speeds, and a normally open pair of contacts for the highest speed. Lower speeds are controlled by reducing the voltage to the motor through a resistor array. The resistors need to be intact to pass the current to the motor. If the blower works on the highest speed only, the resistors and the relay are suspect. If the blower works on the lower speeds but not the highest, the relay is suspect. If the blower does not work at all, the switch and motor are suspect.

If you are not getting any blower action on any speed, remove the blower motor electrical connector (purple wire) and test for voltage with the fan controls on. If there is voltage present but the blower doesn't run, the motor is the likely cause. If there is no voltage, the circuit is the problem.

 

Thanks for the info Vader. I can't get around to checking it today, but I will tomorrow. I forgot to mention that the a/c(heater,etc) doesn't work no matter what speed it's on. I guess I have to go buy a voltmeter. Well, I wanted to adjust the fuel pressure and check the fuel mixture anyway, so I needed a voltmeter anyway.

If it is the blower motor, do I ask for a heater blower motor? I'm asking because I didn't know that that motor was also for the a/c.

 

Coach,

Same blower. The last time I bought a "lifetime" replacement blower it was a whole thirty bucks or so.

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Later,
Vader
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Justice and Freedom will Prevail

 

Are you saying that no matter what speed you put your fans on, that it remains the same speed? If so, I suspect it could be the switch for the fans. They tend to fail fairly frequently.

 

Thanks Vader, and Glenn. I was expecting more than $50 for a motor, so around $30 isn't that bad. I need to call the parts stores and ask for prices.

Glenn, it's a little weird. The a/c system stopped working once. I checked it a little while later and it worked normally. Then, the next day and since then it wouldn't work. No matter what speed I put the a/c(heat,vent,defroster,etc.) on, no air comes out.

Oh by the way, I'm looking to get a multitester. There's a local Harbor Freight dealer, that I've bought from before. The only thing is they have several models. What should I look for in a multitester for automotive use. I'm not planning on using it very often, so I don't want to spend a lot of money for one. Of course I don't want junk either. I believe the brand that HF carries is CEN-TECH. The other places I could buy from are Radio Shack, parts stores, etc. What's worked for you guys?

Thanks again for all your input.

 

Most likely, if nothing electrical operates, the problem is that the power supply connector to the control head has burned up.

Take the control head out; find the single brown wire all by itself that goes to the "mode" switch, that's the one that carries power to the head; follow it back into the dash about a foot; there you will find a connector of extremely stupid design. It will basically be a pile of ashes. Cut it off, and replace it with a set of insulated spade connectors, preferably the heaviest, thickest ones you can find.

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

 

I have a problem relating to this. Every time I turn on the blower my engine starts to skip. I unpluged the A/C compressor so I know it is not loading the engine. I have a brand new alternator so I do not belive the blower is robbing electricity from the coil. How are these related? This only happens when I turn on the blower on HIGH.