66 blower motor removal

[darth_linux]

I’ve got the three 7/16” nuts removed and the three 1/4” screws (indicated by the screw driver tip) removed that seem to be holding the retainer/plate to the housing, but the motor and wheel aren’t coming out. Can’t tell if I’ve missed something or it’s just stuck and I need to pull harder. Any thoughts?

 

[darth_linux]

I read a similar thread over on FBBO and the answer was to remove the three screws. I put the three nuts back on so I could get some leverage and then tried to pull. The whole assembly wiggles a lot, but it will not come out. The exploded diagram from the parts manual doesn't help either, as it doesn't even show the three screws . . . stumped, and getting nowhere fast.

 

[Just Carbs]

As I remember it, the nuts stay on, the screws come out, and it's a very tight fit.
I just worried it out there.

 

[darth_linux]

As I remember it, the nuts stay on, the screws come out, and it's a very tight fit.
I just worried it out there.

Yeah, that’s what the folks on FBBO said too. Very tight …

 

[Ross Wooldridge]

Those big bolts and nuts are not what they're talking about. Put them back on.

There are 3 very small sheet metal screws that are on the perimiter of the whole shebang - remove those and the entire motor and squirrel cage inside will come out.

 

[darth_linux]

I’ve already taken those out and it still doesn’t come out. It just wiggles.

Those big bolts and nuts are not what they're talking about. Put them back on.

There are 3 very small sheet metal screws that are on the perimiter of the whole shebang - remove those and the entire motor and squirrel cage inside will come out.

 

[Ross Wooldridge]

Hmmm - it should. It's AC equipped, correct? Non AC comes out under the dash...

 

[darth_linux]

Hmmm - it should. It's AC equipped, correct? Non AC comes out under the dash...

Yes, it's AC. The FSM says to remove the screws and then "remove the blower motor unit" or something, so I've done what I need to do, it just doesn't want to come out. I need more leverage to pull I think, but there are hoses and stuff in the way for the heater core and air conditioning. Nothing really to pry against.

 

[3175375]

Yes, it's AC. The FSM says to remove the screws and then "remove the blower motor unit" or something, so I've done what I need to do, it just doesn't want to come out. I need more leverage to pull I think, but there are hoses and stuff in the way for the heater core and air conditioning. Nothing really to pry against.

There might be a cloth, sock or something else wrapped around the squirrel cage.

I remember my dad helping my uncle fix the air conditioning in their station wagon. They discovered a pair of nylons wrapped up in the squirrel cage blower. They removed it and the system worked perfectly. True story.

 

[darth_linux]

There might be a cloth, sock or something else wrapped around the squirrel cage.

I remember my dad helping my uncle fix the air conditioning in their station wagon. They discovered a pair of nylons wrapped up in the squirrel cage blower. They removed it and the system worked perfectly. True story.

Sounds like a good excuse to get out the borescope camera and take a look inside. Thanks for the suggestion.

 

[darth_linux]

I got the blower motor out. The culprit was a little bit of corrosion around retaining ring where it interfaces with the mounting ring.

I used a 12” ratchet extension to go through the under dash vent up to the ferrule on the squirrel cage, and a hammer to apply some percussive persuasion. A few taps did the trick and the unit popped out.

The new motor I got from rock auto is too shallow, so I’ll have to eliminate the insulated standoffs. I can tell from a few things that this is not the original blower motor, but it is quite old. It had the same resistance as the new unit, so I’m not sure I’ll see much benefit, as I was hoping to increase the air flow, and reduce the current draw I was noticing when turning the fan on high.

I’ve got a new gasket coming from Detroit Muscle and after I clean up, repaint and transfer the wire connectors over, I’ll reinstall the unit and do a test.

The motor I removed does not have the CDPD stamping I’d expect to see, but it does have the original style wiring connectors, so now I’m not sure if it actually is the original or a replacement.

 

[Ross Wooldridge]

Glad to hear it came out finally.

Interestingly, 2 of the three blower motors I have (including the one from in the car) test with the same draw/load/performance, and were showing much higher numbers than I felt were normal, but I spoke to a greybeard auto-electric guy here in town, and he says their performance is right in specs. I was all prepared to replace, and I've come to the conclusion that if it ain't broke, don't fix it.

Instead, I'm going to go through all the wiring and the associated connectors within the circuit - from the pushbutton switch, to the fan speed switch to the blower motor resistor and out to the motor. I suspect that my issues lie within those components, and NOT the fan as I originally suspected.

The blower motor you removed looks suspiciously "factory". If you like, since I have two on the bench, I can easily check to see what stampings are there if any and report back. Let me know.

 

[Just Carbs]

Make sure it's not reverse wired. I've had some that would still blow air if the +/- wires are reversed, but low volume and pressure.
I know, it don't sound possible, but it is.

 

[Ross Wooldridge]

They definitely do NOT put out the same CFM that modern fans do, but they blow pretty darn well when one removes all the extra wiring/connectors and other resistance between a good solid 12V and the motor. On the bench they do pretty darn well!

 

[darth_linux]

Glad to hear it came out finally.

Interestingly, 2 of the three blower motors I have (including the one from in the car) test with the same draw/load/performance, and were showing much higher numbers than I felt were normal, but I spoke to a greybeard auto-electric guy here in town, and he says their performance is right in specs. I was all prepared to replace, and I've come to the conclusion that if it ain't broke, don't fix it.

Instead, I'm going to go through all the wiring and the associated connectors within the circuit - from the pushbutton switch, to the fan speed switch to the blower motor resistor and out to the motor. I suspect that my issues lie within those components, and NOT the fan as I originally suspected.

The blower motor you removed looks suspiciously "factory". If you like, since I have two on the bench, I can easily check to see what stampings are there if any and report back. Let me know.

The only stamping the motor has is "Made in Canada". I agree, it looks like a factory unit. Perhaps it was a factory replacement from dealership 30 years ago? Who knows. The retaining ring has suspicious scratches and marks UNDER the rubber seal that lead me to believe this whole unit was R&R'd at some point in it's life, perhaps with an OEM or NOS motor . . . I'm gonna put the new motor in for excretion and laughter and see if I get more flow than before with less draw. I'll keep the old motor for posterity's sake, or perhaps to give to someone in need if indeed it is original and/or within spec.

 

[darth_linux]

Make sure it's not reverse wired. I've had some that would still blow air if the +/- wires are reversed, but low volume and pressure.
I know, it don't sound possible, but it is.

It's pretty hard to wire it wrong on this unit because the ground wire has an eyelet that bolts to the firewall, and the positive has a single prong female connector .. . thanks for the heads up though!

 

[Just Carbs]

It's pretty hard to wire it wrong on this unit because the ground wire has an eyelet that bolts to the firewall, and the positive has a single prong female connector .. . thanks for the heads up though!

It's only been a thing with motors that have been spliced.

 

[darth_linux]

An update for the benefit of future users searching for similar information:

The new motor seems to draw the same current as the old one did, and with the same flow, as Ross suggested may happen. The new motor is a bit louder at the lowest speed - it could be the brushes breaking in or something, not sure. It gets quieter the faster it spins. I'm gonna check the 3 screws that hold the everything together at the firewall and make sure it's not a resonance of some kind.

The fans seems to put out plenty of air to the HEAT and AC settings, but airflow to the defroster is very low. I'm gonna check for a loose ducting connection as CBODY67 suggested. I do feel some air coming out the bottom of the dash when in DEFROST mode - I think there is a bit of an air-bleed built into the heater box doors, but this seems to be more that just a minor bypass. I think it's a leak. Only way to find out is to lay under the dash with a flashlight, and/or use the bore scope camera down the defroster vents and see if something can be seen.

 

[3175375]

An update for the benefit of future users searching for similar information:

The new motor seems to draw the same current as the old one did, and with the same flow, as Ross suggested may happen. The new motor is a bit louder at the lowest speed - it could be the brushes breaking in or something, not sure. It gets quieter the faster it spins. I'm gonna check the 3 screws that hold the everything together at the firewall and make sure it's not a resonance of some kind.

The fans seems to put out plenty of air to the HEAT and AC settings, but airflow to the defroster is very low. I'm gonna check for a loose ducting connection as CBODY67 suggested. I do feel some air coming out the bottom of the dash when in DEFROST mode - I think there is a bit of an air-bleed built into the heater box doors, but this seems to be more that just a minor bypass. I think it's a leak. Only way to find out is to lay under the dash with a flashlight, and/or use the bore scope camera down the defroster vents and see if something can be seen.

If you are really anal retentive, you could plumb in a smoke machine to see where it goes.