Dash AC blower motor

[PeterH-350LE]

After driving 30-45 min with the Dash AC on, the blower motor slows down to a point that hardly any air is moving. I still can hear the switching to the three stages, lo med and hi,
but no air. After an hour or so turned off, the cycle starts again.
Motor going south???

[71tradewind]

Peter i have had similar problems with GM blower motors and have been able to remedy it by drilling a 1/16 or smaller hole"only drill deep enough to go thru the sheet metal" on the bearing end "ie" the bump on the end of the blower motor housing, opposite end from the the fan itself, then I put a few drops of 3in1 oil into the hole in hopes of lubing the bearing /bushing. then clean the hole with a degreaser and put a dab of RTV to cover the hole. I hope this works for you. Tom

[thenewkid64]

Peter.

I experienced the same thing on the way home form Dallas in MH #2. I belive it was the evaporator freezing over and not allowing air to pass. I turned the temp down so the compressor would not cycle and the air flow slowly got better and came back to normal. I have a weird groan in the motor when it starts or is on low, so I am going to need to replace it but it worked for the trip home just fine.

[71tradewind]

Good point Brett ! My tow vehicle was doing that last week.

[PeterH-350LE]

Thanx for the replies.
Tom, I went in there a few weeks ago and "injected" some lithium grease on both ends (two shafts coming out of this motor) with a make-shift tube extension for the spray can. That did not fix it, if the bearings really are the problem. I may have to dig deeper, as you suggested.
Brett's comment got me thinking. When this happened the first time I noticed water running out of the AC drain pipe long after I shut the motor and the AC of. Kinda puzzled me. The freezing over would explain it.
Brett, the groan you hear could be the fan(s)
hitting the fan housing. I had the same problem and fixed it by unscrewing the motormount and slightly moving the motor to one side. It's extremely hard to reach.

[PeterH-350LE]

hmmm, hanging at the local Airstream lounge, I overheard 59toaster saying to thenewkid64:
>>The A/C may be over charged. Take it to a local place and probably looking at just a few bucks to fix that up.<<

I drove 1200 miles with the AC blasting and then when leaving Lubbock, Texas the problem started a few hours into the trip.
Simple logic would indicate that freezing over may not be my problem....

[Chas]

Peter,

Sounds to me like it is freezing up which is a symptom of it being either undercharged or a loss of airflow. Fans will make strange noises whenever they can't move air, running in a stalled environment as with a blocked evaporator core. I don't like messing with auto a/c's myself, for the most part I will only do my personal vehicles and that's it, they are just plain frustrating to work on, too many variables. But, if you need some help on it just drop me a line.

Chas