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post #2 of (permalink) Old 12-10-2017, 04:45 PM
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Location: Yadkin valley, NC
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Re: 1979 Thunderbird Landau Not Blowing heat or AC. Help?

I'm unfamiliar with your particular model year so can only give you some general guidelines.

"Something moving around" is probably the various vent doors and such. These are vacuum controlled and therefore independent of any electrical.

The fuse panels for these cars can be troublesome as the contacts can corrode. Always check fuses using a voltmeter at each fuse output. Typically there are two sides to the panel, one side is "always hot", while the other is "hot at key on". Remove each fuse and clean the contact areas with electrical contact cleaner (spray can) and a handful of Q-tips.

The fuse panel feeds some kind of multi-position switch, which in turn feeds the motor. So check voltage at the switch input side (usually one "hot" wire, and maybe a second ground), then again at the output side (usually three "hot" wires corresponding to the fan speeds). This way you can isolate what is broken, a fuse powering the switch, the switch itself, or the motor.

1964 Thunderbird 390 V8, AOD, F.A.S.T. EZ EFI 1.0, Victor intake, MSD Ignition.
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