Just bought my daughter a 1991 Cherokee Laredo. Anyways, the air works(was converted to R134)but the fan speed when placed on high, varies from medium to high. One second it will be blowing strong, the a few seconds latter it slows down. Any ideas on what needs to be done to fix it. TIA

 

been searching on here for over an hour and came across this info. The thread mentions a "blower resistor" located behind the glove box. It states if the blower doesn't work at all or works only in high, that it may need replacing. Mine works at all speeds but when set to high it goes from strong to weak and visa versa. Any help once again appreciated.

 

saw several mentions of the blower fan motor made so I went out and took a look. Mine is not under the coolant reseivor tank but instead is completely visible. Not sure if it is the original or not. The sticker on it says Siemens. There is some foam sticking out on one side but not the other, which leads me to believe it has been replaced at one time. Heck, the old girl is over 20 years old. I'm searching for some answers, but I am not over mechanically inclined so once again any help is appreciated.

 

ahh come on people....no one has ever run into this....am i in the correct forum?

 

Sorry I can't help you but the response you have received is typical of this forum.

 

Do u mean the fan speed actually changes from strong to weak (fast/slow) or do u mean the airflow at the dash vent goes from strong to weak? Is it weak when accelerating and strong when decelerating?

What does that mean?

 

[QUOTE=djb383;1802032]Do u mean the fan speed actually changes from strong to weak (fast/slow) or do u mean the airflow at the dash vent goes from strong to weak? Is it weak when accelerating and strong when decelerating?



Thank you for a response. Now that you ask I am not sure if the fan changes speed or the air flow varies. I am leaning towards the second. She has only had it a few days, but if I remember correctly it gets weaker as she accelerates and stronger when she is slowing down. But even just cruising down the highway, it will go from strong to weak then back again. The reason I mentioned the fan speed was the seller told me that the "fan changes speeds at random". But then again he might not have known for sure. When I put it on heat the fan seems plenty strong. If it is the second, what can I do? Thanks again for your response.

 

Could be a vacuum leak....under acceleration vacuum is reduced, under decel vacuum increases. The vent selector is vacuum controlled....when vacuum is lost, the vent position goes to the factory default which is top of the dash vents thus drastically reducing airflow out the middle dash vents. There's a vacuum canister/ball behind the front bumper.....start there looking for vacuum leaks, working your way back to the dash.