Heater motor volume

Chinook · 10-18-2020, 10:14 PM

Has anyone done any type of modification or replaced their heater blower motor with something that moves a larger volume of air? in the winter it seems theres not enough air flow to move the heat, and in the summer its the same with cold air from the AC.

Im hoping i dont have to disect the dash to yank the heater plenum out for inspection as winter has set in.

carringb · 10-19-2020, 12:05 AM

If the fan motor is in good condition, and nothing is blocked, it moves A LOT of air. Like enough to using high is annoying.

That said... over the last year mine got weaker, and eventually stopped working a couple weeks ago. I could get it moving for a trip with a good thump, until a couple days ago.

Your fan motor might be on its way out, or the A/C evaporator might be plugged with debris. Anything that enters the windshield cowling ends up here. And all air passes through the evaporator before being split through the blend door for heat. To clean this out, you have to remove the blower anyways. Which requires pulling the battery and tray, and unbolting the ac filter-drier to push it out of the way.

Chinook · 10-19-2020, 12:30 AM

Oh my, so i can clean it out by just removing the fan from the plenum in the engine compartment? What im thinking is that dog hair maybe got sucked in there and plugged it up? Do you think thats possible? I have two blue heelers that shed alot in the warmer months. They travel with me always, its a full time job to keep up with the shed hair.

I took the cover off of the heater core inside under the dash but it wasnt plugged up from what i could see. But i was looking for the source of water getting in the cab floor at that time and not so much looking to fix the air problem. The blower motor seems to spin properly and doesnt make any weird noises, (not that it means its good i guess).

Do you think it could be clogged up with dog hair? I have never had one apart so i dont know how it goes about ingesting and circulating the air. I know if you set it to "vent" it circulates fresh outside air into the cab on most vehicles. But doesnt it recirculate interior air when its on heat or AC..??

Seems if it was ingesting fresh outside air constantly when running the AC it would never be able to effectively catch up and cool the interior of the cab, same with the heater??

Chinook · 10-19-2020, 12:57 AM

I will yank the fan and see if its clogged up in there. I wonder where it pulls interior air from when its recirculating interior air to heat or cool. Maybe i can install a screen over it to prevent dog hair from being pulled in.... ??

carringb · 10-19-2020, 10:20 AM

Yup. Dog hair will definitively get in there if you use MAX A/C, since MAX is A/C + recirc. The return register is under the passenger dash, and is a straight shot into the blower motor. Actually, besides the A/C evaporator, dog hair hair could easily wrap around the squirrel cage. The heater core is relatively protected, since all the air goes through the evaporator first. I was surprised how many pine needles were in my evaporator, considering I only park under evergreens when I'm camped. I don't have any at my house. A small vacuum hose can be stuck through the blower opening to vacuum that out. While the blower is out, you can inspect the motor itself though the vent-port on the bottom. My brushes were simply worn out. Once the battery out, it might not be too much trouble to crack open the clamshell plenum holding the evaporator, but I was able to get enough debris out, so I didn't try.

Chinook · 10-19-2020, 10:29 AM

Yes i run it on max ac all the time because it doesnt seem to blow enough air unless its on max. Ok thanks man, i will take that blower motor out as soon as i get another warm day here. Its gotta be dog hair clogging things up. I will try to fabricate some kind of screen to catch the hair before it gets pulled into the plenum once i locate the intake duct.

Orv · 10-21-2020, 01:25 AM

It's not so much a duct as just an opening into the fan intake with a movable door to seal it. It's been a while since I looked under there, but if you can move the lever between MAX and NORM while you look you'll probably see and hear the door moving.

JWA · 10-21-2020, 04:45 AM

Here's a short video of the Max A/C function showing how the recirculating door works:

https://www.youtube.com/watch?v=v_DUDkEZHYo

You can see the blower motor squirrel cage spinning so could be easy to see if there's any dog hair etc in there before removing the motor?