C3 blower motor help please

[David W.]

I have read many forum posts on this subject but still need help please.

I have a 69 AC car. Blower fan weak, only runs on high speed setting.

From what I have read, that should mean the blower motor resistor or connections. I have removed my resistor and both it and the connections look good.

1. If the metal, springs and connections on the resistor look intact, does that mean it is ok, or should I still replace? (see picture)

2. Also, there are 2 cut wires connected to something that looks like a capacitor attached to the top of my blower motor, can anyone tell me what this is, where the wires should be attached and if this may be my problem? (see picture)

3. I have read that upgrading the ground wire can help. Can someone show me a labeled pic or diagram of which is the ground wire coming from my blower motor?

4. I have also read to clean debris from plenum. Is this the hollow box under my resistor? If so, mine looks good.

And my inline fuse towards the passenger side also looks good (I assume the correct one for blower fan but from what I have read the fan would not run on high unless fuses good).

Any and all help greatly appreciated.
Thanks

[Greg S.]

Re: C3 blower motor help please

I am not sure how your fan works at all. The cut wire you show is the power wire to the motor. The picture attached shows a 75 motor. The purple wire from the harness attaches to the rubber connector. The cut end of your wire should have a connector that plugs into the spade connector on the motor. The black wire from the harness is the ground. Those recommending improving the ground usually mean to add a ground wire from any good ground on the frame to any of the bolts that mount the fan. I don't know how to check the resistor other than you could check for continuity on the contacts.

[David W.]

Re: C3 blower motor help please

I am not sure how your fan works at all. The cut wire you show is the power wire to the motor. The picture attached shows a 75 motor. The purple wire from the harness attaches to the rubber connector. The cut end of your wire should have a connector that plugs into the spade connector on the motor. The black wire from the harness is the ground. Those recommending improving the ground usually mean to add a ground wire from any good ground on the frame to any of the bolts that mount the fan. I don't know how to check the resistor other than you could check for continuity on the contacts.

Thanks. From what I can determine, the capacitor and cut wires on the blower motor are related to the radio noise suppression system with AC cars, and is clearly now disconnected. I did find another ground connection to the motor which was loose. By just cleaning my resistor and contacts, tightening the ground connection and adding a second thicker gauge wire ground, my fan is now blowing on all speeds and is pretty darn good. The AC may not be terribly cold, but my C3 blower is fixed and should be adequate as I dread trying to access it to upgrade it to a C4 motor and/or fan cage. Done for now. Next an r134 retrofit and recharge and hopefully decent AC.

[Greg S.]

Re: C3 blower motor help please

The C4 motor upgrade is not too difficult. If you do it order a 84-5 C4 fan motor as it is very close. You will need to slightly enlarge the hole for the cooling tube to fit. I ordered a 12 inch square 3/4 inch piece of black plastic for the spacer. A router with a straight bit will cut the round hole for fan. Use the new motor as a template. Get some 1 1/4 bolts from Lowes to replace shorter ones. I used strip caulk for seal but others will work. When done the increase in air flow is noticeable.

[Greg S.]

Re: C3 blower motor help please

Forgot to mention to check that fan has clearance and will turn. You can use jumper wires or use clay in plenum for test fit. I had to sand the edge of fan slightly. You could also use another thinner shim.