A/C fan problem

[RDusch]

My A/C fan will run for a while then slow down, then speed up, then down ect.

finally it will just quit.

Sometimes it will run a while then when i shut the truck off, when i restart it the fan will not run.



After searching i found no clear cut answer, anybody else having this problem

or fixed this problem??



Rick

 

[B.G. Smith]

I would guess you have either a loose connection to the motor or the motor is worn out. I believe you can get to the motor without removing the A/C housing, If so I would suggest disconnecting the wires to the motor and hooking up directly to a 12 volt supply and see if it still acts up, is so then the motor is defective. The first place I would look for bad connection would be the resistor block, it is mounted to the A/C housing under the dash on passenger side of truck. bg

 

[RDusch]

I replaced the ignition switch today, the original was burnt pretty bad, took the truck for a test drive and worked great for half a block then the fan slowed down again.
I went and ordered a new fan and resistor, i'll install them this week and see what happens.

 

[BDaugherty]

It sounds like a fan motor to me. It could be in the control switch, but it mostly sounds like a motor. You could test it by piggybacking a volt meter to the wires going to the motor and watch the voltage while the motor is acting up. If the voltage stays fairly constant while the motor speeds up and slows down, then it's a bad motor. If the voltage fluctuates with the motor, then you may have a control problem.

 

[RDusch]

I piked up the fan and resistor today got it home and the fan was broken, so installed just the new resistor and ran the fan back to the store. to my suprise the old fan worked perfectly, this thing will blow some serious air now, worked fine for a 30 min ride.

The old resistor was dark and burnt looking and the casing material was cracked.

Looks like between the ignition switch and resistor fan is back to normal.

Rick