New Fan Motor is possible Solution to no low or medium air blowing.

[McCann]

Hi All,

A few months back I mentioned that Sonny Boy's 94 Cherokee did not have any low or medium fan motor speeds and only worked on high.
(and you should have heard mama whine when she had to drive it on a hot day!)

I asked mechanic # 1 what was wrong and he said to replace the resistor under the dash on the passenger side...so I did for about $30. It worked good (as I reported on the forum) for about 1 week and then quit working again. Mechanic # 1 did not mention a possible cause for it reblowing.

Last week I took the truck to a different mechanic for a different issue and mechanic #2 said it was probably the blower motor and that the brushes in the motor were probably bad...probably pulling to many amps and I would keep blowing the resistor because it gets too hot running that many amps.

I asked him what amps it should be pulling and he said about 10 amps. I had him test it and it was pulling 20 amps. (I think those are the right numbers but if someone knows them for sure...please post).

We (mechanic) replaced the motor and the resistor and now it sounds better and is working correctly. Of course it has only been a week. Not sure on price yet but suspect it will be about $110 total.

For those of you that are having this problem...I would have the blower motor tested before you throw away money for the resisitor just so it can blow out again.

Oh yeah...when I was in the mechanic # 2 shop I saw a resistor for a different model vehicle laying on his desk and he said that he replaces a lot of resistors and blower motors as they will wear out on all vehicles if the fans are used all the time. He said the vast majority need blower motors replaced.

I supose the same logic would probably apply to any electric motors on the vehicle. Later Mike

[MT-2500]

Originally Posted by McCann

Hi All,

A few months back I mentioned that Sonny Boy's 94 Cherokee did not have any low or medium fan motor speeds and only worked on high.
(and you should have heard mama whine when she had to drive it on a hot day!)

I asked mechanic # 1 what was wrong and he said to replace the resistor under the dash on the passenger side...so I did for about $30. It worked good (as I reported on the forum) for about 1 week and then quit working again. Mechanic # 1 did not mention a possible cause for it reblowing.

Last week I took the truck to a different mechanic for a different issue and mechanic #2 said it was probably the blower motor and that the brushes in the motor were probably bad...probably pulling to many amps and I would keep blowing the resistor because it gets too hot running that many amps.

I asked him what amps it should be pulling and he said about 10 amps. I had him test it and it was pulling 20 amps. (I think those are the right numbers but if someone knows them for sure...please post).

We (mechanic) replaced the motor and the resistor and now it sounds better and is working correctly. Of course it has only been a week. Not sure on price yet but suspect it will be about $110 total.

For those of you that are having this problem...I would have the blower motor tested before you throw away money for the resisitor just so it can blow out again.

Oh yeah...when I was in the mechanic # 2 shop I saw a resistor for a different model vehicle laying on his desk and he said that he replaces a lot of resistors and blower motors as they will wear out on all vehicles if the fans are used all the time. He said the vast majority need blower motors replaced.

I supose the same logic would probably apply to any electric motors on the vehicle. Later Mike

Each car is different but the fan motor amp draw needs checked when you have resistor problems.
Sometimes it is a motor problem and sonmetimes it is not.
But all need proper testing.
MT

[McCann]

Hi MT-2500

I absolutely agree that testing is vital.

Sometimes you get comfortable in the world with people and know they are giving you good advice.

Sometimes that advice is accurate and sometimes that advice needs to be backed up by technology...that is where I dropped the ball...I was in a comfort zone with what the mechanic told me and it cost me an extra $30 (plus time to drive to get the part and replace the first time) for something that would have taken about 2 minutes of the mechanics time.

The sad part is...after it blew out again...mechanic # 1 said "oh yeah, it is probably the blower motor"...wish he would have said that before I replaced the resisitor.

I won't make that mistake again. Later Mike

[MT-2500]

Originally Posted by McCann

Hi MT-2500

I absolutely agree that testing is vital.

Sometimes you get comfortable in the world with people and know they are giving you good advice.

Sometimes that advice is accurate and sometimes that advice needs to be backed up by technology...that is where I dropped the ball...I was in a comfort zone with what the mechanic told me and it cost me an extra $30 (plus time to drive to get the part and replace the first time) for something that would have taken about 2 minutes of the mechanics time.

The sad part is...after it blew out again...mechanic # 1 said "oh yeah, it is probably the blower motor"...wish he would have said that before I replaced the resisitor.

I won't make that mistake again. Later Mike

10-4 on that McCann
When you have a problem always look for what caused it.
MT