C2 heater and A/C blower motor

[Larry S.]

I need to repair/replace the heater and A/C blower motor on my '67 SB with A/T and A/C. The shop manual says to remove the coolant expansion tank straps, move the tank out of the way, and then simply take the blower motor out. But I can't even see the blower motor. How do I get it out? Thanks.

[Joe R.]

Re: C2 heater and A/C blower motor

The blower motor is tucked up inside the fender. As you face the firewall, the blower is located to the left of the A/C evaporator housing and behind the expansion tank. I think the shop manual is correct that you can remove the blower motor once the expansion tank is out of the way.

By the way, are you sure that the motor is the problem? If it's running but has bearing noise, then clearly the motor has to come out. However, if it simply isn't running, the cause may be in the switches or wiring.

[Larry S.]

Re: C2 heater and A/C blower motor

Joe, it's simply not running. I just 'assumed' that the motor had died, but I will now check the switch and wiring. Thank you for the tip.

[Jack H.]

Re: C2 heater and A/C blower motor

Also, because the blower motor assy screws into a FIBERGLASS firewall panel (vs. stamped steel on passenger cars) it HAS to have a discrete ground wire... If that's unplugged (and/or with a radio equipped car, the RF noise capacitor is defective), you wind up with an incomplete circuit path--hence no blower motor operation.

Last, since this is a DC motor, there are internal carbon brushes that naturally wear as the motor spins. There's only so much life in the brushes.

So, an add-on to what's already been posted, you do NOT have to hear bearing noise to detect a need for the blower motor's overhaul! If the carbon brushes have expired, the spring that holds them in contact to the motor's armature begins to 'bite' into the armature. The good ole boyos call this 'throwing lead'...and rotational friction goes WAY up with continued operation resulting in destruction of the armature shaft...

JUST before you reach the point of no-return, these motors will either 'stall' on start-up and/or run VERY slowly. That's the telltale that it's time to either replace or repair the motor....

[Joe R.]

Re: C2 heater and A/C blower motor

Hi Larry:

I checked my car tonight and the connection to the blower motor is located right behind the expansion tank and can be accessed without removing the tank if your arms aren't too big. You can disconnect the power lead and check for 12 volts at that point when the blower is switched on.

Before you do that, though, try checking the heater fuse in the fuse block. Also, for A/C cars only, there is another fuse in the red wire that runs along the drivers' side fender. I would have to study the wiring diagram for a while to determine whether either or both of these fuses could cause the blower motor to quit, but its pretty easy to simply check the fuses.

The wiring for A/C is a bit complicated, since portions of the power are routed through two fuses, the blower switch on the dash, the A/C switch behind the glove box, the A/C relay mounted to the evaporator housing, and the resistor used to set the fan speed. I don't think that all of these can cause the blower to quit, but it would take a little time to sort out the wiring diagram and figure out which of these could keep power from the blower.

So, maybe the way to start is to first check the two fuses, then check to see if power is being provided to the blower motor when it is supposed to be on. That will point to what needs to be checked next.

[Mark H.]

Re: C2 heater and A/C blower motor

I've got a C2 with A/C too, and although I never have taken the blower assy out I believe there is a housing (with screws around the perimeter) just behind (towards the firewall) that the blower resides in. It's raining here so I can't (too lazy) get to my car or owners manual. If you need me to look Mon, email me back and I'll check it for you.

Mark

[Allan J. Wicklund]

Re: C2 heater and A/C blower motor

Is there a more efficient Fan and Motor that is a direct replacement? Al W.

[Joe R.]

Re: C2 heater and A/C blower motor

Hi Allan:

I recall reading an article that showed different versions of the squirrel cage fan that was used during the C2-C3 era. The author felt that some versions would move more air than others. It is possible that the article was in an old Restorer, but I can't recall for certain.