AC fan speed control

In the meantime, I would consider just hot-wiring the fan so it ran at full speed, so at least you have something in the heat.

Yep!! Got them wires twisted together and dangling down to the floorboard. Another thing I had been meaning to do was to change the AC cabin filter as part of the routine maintenance. When I got into this problem, the filter was easily accessible, so I pulled it out. That thing had never been changed!! It's a wonder any air at all got through. Now, on high speed, it will blast you back into the seat.

Larry In the back yard, under the oak.

Hey Larry! Do you mean the stealership guys haven't been changning or cleaning the cabin air filter? I thought they were supposed to do that as part of the $150 oil change. Maybe I will check up on those guys - hard to do though, cause they all eat Kudzu and write in those funny little characters. (Really I like Kudzu - some of my best friends eat it and like it also. As a matter of fact, I have been trying to get the Petunia Club downtown to start planting it in the flower beds, but they are so uptight about some things!)

mcbrue under the bridge in the trailer down by the river

Yea, they must have been ripping the doctor lady that used to own this thing. She gave me stacks of receipts showing how good she maintained the car, always had it serviced on time, rotated the tires, filled the windshield washer fluid.... you know.. all the important stuff. When I got it from her, I had to do the minor stuff like change the radideator hoses and fanner belts and batteries and braking pads and fuel filters (that got rid of that weird hesitation she complained about) and some other unimportant stuff that the dealer guys just couldn't be bother with (or maybe couldn't find). But that's OK... I'm happy. It starts when I turn the key and gets me back home everytime (at least so far) and the girls tell me how pretty it is and the boys all wish they had one. Life is good.

Larry In the back yard, under the oak.

It's Fixed!!!! The junk yard coughed up a good part today and the AC now functions as advertised!! The Blower Motor Control Relay was bad. Plugged in the replacement about half an hour ago and it works perfectly. Just an observation.... when I changed the cabin air filter (the one located behind the glove box) it was clogged!!!! I can't begin to tell you how badly it was stopped up. But now with the new filter, the volume of air flowing out of the vents is tremendous. I can't help but wonder if the restricted air flow somehow caused the Relay to over heat and malfunction (short, open, whatever)?? A five dollar air filter cost me $120 for a used Control and hours of sweating, not to mention the cussing. And, Yea, how come the service guys didn't do the routine replacement when the good doctor lady owned it and took it to them all the time? Huh? How come?

Larry In the back yard, coolly under the oak.

No, unless the air was somehow cooling the relay.

Restricting airflow through a fan makes it draw *less* current, because it is doing less work.

Your intuition is incorrect.

Put a meter on the fan and try it if you don't believe me.

Richard is right, Xplant. If ther airflow is blocked, then the fan will speed up, and draw less current. It has to do real work to push air. If ther air can't be pushed, then all the fan motor has to do is spin the fan against its own internal friction. Less opposing force means less power drawn.

If you don't believe this, take a vacuum cleaner with a hose, start it up, and plug the hose with your hand. Listen to the motor speed up.