Automotive Air Conditioning Information Forum (Archives)

Provided by www.ACkits.com

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

AC blower

ldj1002 on Mon May 28, 2012 9:59 AM User is offline

Year: 2002
Make: Ford
Model: Crown Victoria
Engine Size: 4.6?
Country of Origin: United States

Yesterday AC wouldn't come on. I raised hood and compressor was running and lines were froze up. So I knew it was the blower not working. I checked fuse, it is good. Put fuse back in, still no blower. I messed with controls a little and the blower started working. A couple times past few months AC wouldn't come on right away but in a few seconds it would start, I suppose that was blower then. Yesterday was by far the longest it took for it to come on. Any ideas? Car has the Automatic AC

GM Tech on Mon May 28, 2012 12:10 PM User is offline

Do the whaaaaap test-- next time it won't come on-- whaaaaaap it with your foot, hammer, fist whatever-- if it comes on, you need a new blower motor..DC motors do this, the bearing/bushings wear and armature gets off center and brushes don't contact right and then the whaaaaaap centers everything and it starts running again-- until you shut it off. I've had customers whaaaaap for 6 months or more until they finally cough up the funds for a new motor...

-------------------------
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 May 28, 2012 2:31 PM User is offline

Yeah what GM Tech said. Same thing works for starters by the way. If you want to be more scientific about it, you can measure the voltage at the motor when it is supposed to be on. When there is 12 volts but the motor is not turning, it is bad.

Edited: Mon May 28, 2012 at 2:40 PM by mk378

ldj1002 on Mon May 28, 2012 3:22 PM User is offline

OK, next time it stops I will check voltage. However if the motor had voltage but not turning because it was stuck binding or what ever, wouldn't that fuse had blown? It had been on a good while without blowing. Since that fuse didn't blow then isn't fuse is to heavy of something?

GM Tech on Mon May 28, 2012 4:10 PM User is offline

Quote
Originally posted by: mk378
Yeah what GM Tech said. Same thing works for starters by the way.
\
Don't forget fuel pumps-- I've whaaaaaped many a fuel tank to kick one on- right before the tow truck got there.....

No voltage is bad too!


-------------------------
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 May 28, 2012 5:18 PM User is offline

When the brushes wear out the motor will become an open circuit -- intermittently at first. You're right that if the bearings seized the fuse would probably blow, but that's a different problem.

ldj1002 on Sat June 16, 2012 10:25 AM User is offline

OK, now 3 weeks later blower motor quit again. I pulled the plug and checked voltage. It has voltage. Next I used jumper wires and went to blower motor straight from battery and it runs. So what now, hook up a wire to the motor with a toggle switch and use it that way? Since I have voltage at the plug maybe the ground is bad?

mk378 on Sat June 16, 2012 11:06 AM User is offline

Measure voltage with the motor plugged in. Push the meter probes into the back of the plug.

Something about the system (most likely the motor) is intermittent, so it is not surprising that it can stop and then start working again when you do something else. Don't jury rig the wiring, troubleshoot and fix it right.

GM Tech on Sat June 16, 2012 11:57 AM User is offline

Problemo is intermittent- you bumped it when you tested it....wait till it don't work- leave ignition on- and whaaaaaap it-- if it comes on- replace blower motor and quit fooling around....I've done 50 or more this way.....true test of a worn out motor is the whaaaaap test-- of course you have voltage to blower- the brushes are not square to the armature- they are worn out plain and simple

-------------------------
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......

ldj1002 on Sat June 16, 2012 1:13 PM User is offline

I have whapped the motor. As of yesterday when blower quit only time it has run is with 12v applied to motor from battery. It runs that way every time. I disconnect jump wires, plug motor in and it won't run, undo plug do jumper wire again and motor runs. I ask question and want to be sure I have ask correctly before I get another motor. Sure seems like that motor is good. I have jumped it a dozen times and it never fails. Whapping it doesn't make it run with it plugged in or make it not run with jumpers. IE hitting with a hammer has no affect.

mk378 on Sat June 16, 2012 1:29 PM User is offline

If there is zero volts across the motor with everything plugged in, the problem is that the car is not powering up the motor. Measuring with the motor not plugged in is inconclusive, as there may be some current path through the car but not enough to flow the motor current.

Edited: Sat June 16, 2012 at 1:30 PM by mk378

Garry123 on Tue June 19, 2012 3:21 AM User is offline

Ac blower are most important part in a AC.Adjustment cooling depend up on Ac blower.
commercial air conditioning sydney

ldj1002 on Tue June 19, 2012 11:57 AM User is offline

UPDATE on AC blower.

New blower, still it won't blow, what the *!#. I googled Crown Victoria AC blower not working. I got a lot of hits and they all said it was very common for the blower resister to go out. Also said when you get old resister out to look at the plug real good. When motor is going out that it will have evidence of burning or arching at the plug causing resister to go out. If plug is good then motor is good. I bought new resister and now I have blower working. Wasted money on blower motor.

GM Tech on Tue June 19, 2012 10:59 PM User is offline

The old worn out blower would have smoked that new resistor-- you did right by replacing blower along with resistor....old motors pull more amps than new ones- then they fry resistors-- simple as that-- if you don't believe me- then return the new blower motor and see for yourself....

-------------------------
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......

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.