Heater fan inop

71 MGB---Heater fan motor inop. Switch seems OK according to continuity check. I plan on direct hook up of battery to black and green/yellow leads from fan motor. ?--If I need to trace wiring, where do the wires from blower motor terminate and also where do the wires from the fan switch terminate? I think there are 3 of these. I have not seen any inline fuses, nor do I see one in wiring diagrams. I don't want to unwrap the harnesses for sure. I don't plan on driving this in cold weather but I would like to have it working properly if feasible. Thanks.

Dwight

Dwight, this is one of the easier systems to troubleshoot and repair. The motor leads hook to the harness right at the heater box; there are a couple of bullets and snap connectors right there. There should be a green w/yellow trace wire and a black wire. The colors are probably not visible from being in the engine room for 38 years.

You can check for voltage at the snap connector against a good ground. If the voltage is there then remove the motor and pull it out to see if it spins freely. If it doesn't spin freely then you need to service it. No big deal, it involves pulling the squirrel cage off, remove the end caps and lube where the armature shafts go throught the end cap bushings with lithium grease. If you have a bench with a power supply it makes it even easier. A small battery charger would be acceptable to test the motor.

Wray, thanks for your rapid input. I have been unable to pull the connector apart for the black lead coming from the blower motor so far, however I confirmed that the blower motor works by hooking a battery up to the green/yellow lead from the motor and then found a ground.
Problem is I have been unable to get power from the engine side of the green/yellow connector. Do you know the routing of this wire to it's power source and where does the power come from. IE, does it share a fuse with something else for power? Also the wires from the switch has to be involved somehow. I sure hate to tear the car apart to trace wires if you or anyone has a better idea. Nothing is ever easy for me it seems. Must be that little black cloud overhead or the ghost of the lucas electrical gods.

Dwight

You need to download a colour wiring diagram from here. Look for your cars year (?71) and you can trace the wiring of the fan motor.

http://www.advanceautowire.com/mgb.pdf

Kent,

Those prints were very helpful. Thanks a bunch. Actually, I found that someone had used electrical take to tape two green bullet ended ended wires located behind and right side of the center panel, to right of my radio. contact was not being made. I fabricated a new connetor and all is well now. I have no idea why it was lke that. Thanks again to all that offered help. Hope you all have a great Christmas!

Dwight