Heater/AC blower motor upgrade option on 85 6.2L???

[jawjadawg]

I've got a pretty weak blower motor, especially at the lower fan settings. I don't think I've got a resistor problem. Are there any bolt in options from other vehicles or later years which will produce better air flow? I found a thread where someone says to use a later model year for better air flow. The poster says he uses a 94 pickup, but that's the same part #.

 

[diesel4me]

It used to be the older 73-79 trucks had a bigger motor and fan if it had A/C...not sure if they are different after 1980 or so or not..or if the A/C motor and fan fits in a non A/C heater box...

I think they'll fit,I remember putting a heater motor and fan from a 73 Malibu with A/C that had a steel fan that was longer than the plastic one on the original in my '77 GMC..heater worked a lot better with that one..that motor had permanent magnets and the original had regular windings too..

My "81 G-10 van had a "hi-output heater" but no A'C ,and that things blower motor cranks compared to the one in my '82 GMC with no A/C ..that one on hi speed sounds like mediuim on the van's blower..

It could be aftermarket motors are "consolidated" now,if they know one fits all,to reduce inventory..

 

[kennyw]

Are you sure it isn't just worn out?

 

[jawjadawg]

It might be, but my (limited) experience with electrical motors has been that they don't lose their speed as they age. For me at has usually been that one will just quit, wear out a bearing (which can be heard), something else breaks, or something burns up (which can be smelled). This is the first time I've diddled around with a blower motor, so maybe they do lose speed or torque with age.

I'd be interested in hearing from someone who had this problem and fixed it by replacing with the same motor. They aren't real expensive, so it would be nice if that's all it takes.

 

[diesel4me]

I'd try jumping it right off the battery,to ensure the resistor has not increased in resistance or the switch has poor contacts,etc,before pulling it out and replacing it...if its never been out before,you may find the heater box full of mouse nests too,one truck I had I took the blower motor out to replace it when it failed to work and blew the fuse,ended up having so much of the jute padding from under the rug packed in there by mickey and his friends the blower wheel could beraly spin!...

I used the shop vac to suck it all out,then blew compressed air into the defroster and floor ducts to get ALL the crap out!...then douched the heater box with lysol and bleach to kill the stench and germs..I only had to oil the motor bushings with a few drops of 3 in 1 oil and put it back in,and it was like night and day!...

I was surprised the resistor had not set the stuff on fire ,really.....I "fixed" my wiring so when the blower switch says "OFF" it IS "OFF",it used to stay on low speed constantly the way the factory designed it,and it would start screeching sometimes...a quick snip of the wire going to low speed on the resistor plug cured that annyoying problem!..

 

[kennyw]

It might be, but my (limited) experience with electrical motors has been that they don't lose their speed as they age.

I just proved that wrong fixing my wiper motor. The delay wipers would stop halfway up and then complete the cycle on the next pulse. I replaced the switch and pulse module first with out any change. It ended up being the motor was weak and not pulling itself up far enough before the pulse timer kicked off.

They can slow down due to wear or corrosion.

 

[diesel4me]

I noticed a spare blower motor I kept from another 73 Malibu with A/C that was the engine donor for my van, has a plastic spacer about 3/4" thick under the motors mounting flange,which is probably needed to allow for the longer blower fan on it to clear the heater box...this one has a plastic blower wheel,the other one I mentioned had a metal one,that was the same size I'm pretty sure..

 

[Maverick4x4]

Old thread but I'm dealing with similar issues. Often the blower won't turn on, but after driving for a while, it randomly starts blowing.

And I do have a resident mouse. Well fed on peanut butter, I might add.

 

[MrSchaeferPants]

Check all connections, including ground. Randomly while driving (bumps, vibration) tells me wiring. Easiest place to start is bench testing the motor. Then physically remove each connection, inspect for corrosion/tightness, then re install.

 

[Mullet]

Old thread but I'm dealing with similar issues. Often the blower won't turn on, but after driving for a while, it randomly starts blowing.

And I do have a resident mouse. Well fed on peanut butter, I might add.

I have the exact same thing happening. Time to troubleshoot the connections and hopefully find the problem.