Granger heat motor

[newman 911]

Hello: I just finished the install of my Granger heater motor and it just don't seem to spool up has hard as the old Porsche heater motor, I am judging it right at the heater fan on a 77 911s. Am I doing something wrong, could it be the wires are on wrong. I think I went red to power and black to the other wire????????

Thanx Chris from Ohio

[david914]

Not sure if it means anything, but I did the Grainger motor install this past Fall. On my car there was almost no noticeable increase in air from before the motor install. Since my factory motor was shot when I bought the car, I don't have anything to compare it to. The factory motor must turn at a higher RPM than the Grainger motor as I can't imagine the factory going through the trouble of installing all of that extra hardware just to gain a mere whisper more air.

[ohecht]

I saw in another post that the motor will spin either way based on the wiring, and that person found that red on motor to brown on the car gave the proper rotation.

I am about to do this fix myself, and you may have the fan rotating in the wrong direction. Based on the design of the cage, it would not move any air at all spinning backwards.

Olivier

[fintstone]

Yes..Oliver is correct...simple DC motors run backwards when you reverse polarity..so you need to be careful when you install any fan motor...especially a nonfactory replacement...be it the footwell blowers, carrera oil cooler fan, A/C condensor or evaporator fans, or the engine heater blower. If the fan is turning the wrong direction it will actually cause the motor/fan to fight the air flow from the shroud reducing both the air flow and the life of the new fan motor.

[ohecht]

Am I the only one that had to replace the through-bolts on the motor to make this work? I ground the plate as thin as I could, but I only had about 2mm of threads showing on the motor bolts, so I had to replace them to get enough to mount it to the factory plate.

Olivier

[Wavey]

Originally posted by fintstone
Yes..Oliver is correct...simple DC motors run backwards when you reverse polarity..so you need to be careful when you install any fan motor...especially a nonfactory replacement...be it the footwell blowers, carrera oil cooler fan, A/C condensor or evaporator fans, or the engine heater blower. If the fan is turning the wrong direction it will actually cause the motor/fan to fight the air flow from the shroud reducing both the air flow and the life of the new fan motor.

Thanks for pointing this out - I just corrected this on the original post!

[3.2 CAB]

Dfink had a really good post on this matter. Tells of red to brown and black to yellow power wire to get the blower to function correctly. Hopefully this is the correct thread: skillet to heater blower

[v9ff]

Do these Grainger motors work better than the factory ones? When mine broke, I got a used motor for $50 and it dropped right in with no hassle.

[fintstone]

Steve
No, just a lot cheaper than a new one and cheaper than most used ones.

[Wavey]

And more durable. The OEM motors are fragile and lightweight.

[newman 911]

I took the advice about the wiring, went up to the hanger over the week end and changed the wires and the granger motor, works great. Also the motor running backwards will put out a little air but nothing like it running the right way.

After I hooked the motor up right I went for a little drive to test. There is an area when I am coming home about 7 miles long I run her pretty hard, well during that run I finished off the Throw-out bearing that has been wining since I bought the 911s 77. Now today I plan on pulling the motor and doing the clucth, pressure plate, bearings, 1st gear syncro, oil cooler seals, etc. I was hoping to get this year out of her so I can finish my plane I have been building for 8 years. To many projects going!!!!!!!!!!!

Chris from Ohio

[yelcab1]

I am hoping my engine or tranny let go to, but no luck. Guess I have to find that road where I can push it a little further.