Fan Switch BR wire fried, no blower

[jamesmadconductor]

I hope someone can help me out here, and here is the order of events: a/c has been working fine, with the fan high speed occasionally cutting out, but now I have no fan at all. I have already read over the million threads outlining the situations where only low and medium work, and how the blower relay is only for high speed. I get that, but since I have no fan anymore, and the relay still clicks when the switch is turned to high, I think the relay is not my problem. I am assuming that it is my resistor, but I am wanting to hear any other thoughts before I open up the box to get at the resistor.

With the attached pics, would a failed resistor cause the extreme heat at the brown lead wire?

[snipescastle2]

Perhaps the blower resistor has a broken element or the fan motor has been damaged.its possible the actual fan switch could be bad as well. If you can check the switch in the dash controls for continuity in all three fan speeds you can eliminate that from the problem.if you haven't already done it, I'd change the fan relay and blower resistor, then the fan motor for last. One more thing, if your fan switch connector got melted because of that resistor, I'd be examining that a/c harness for burnt wires,possibly shorted together. I'd hate to see youu damage anything else before finding the root cause.
Good luck
Ben

[davepl]

Mine looked like that too when I did my restoration, though yours is a little worse. I bought a new connector and rewired it (they're available, I should have a part number somewhere if you can't find one) and the problem has not recurred.

And that's with the same resistor, relay, and blower motor. Nothing else changed. So I don't know what caused it originally. Wish I knew!

[jamesmadconductor]

Thanks guys, I appreciate the feedback. I got the resistor out, haven't bench tested yet, but it appears unbroken and only a little obvious heat wear, which I expect. I did look over the rest of the harness and couldn't find any other hot spots, so I think the burn is from something else: the lamp socket that someone had previously not secured and was hanging very close to the plug. The more I think about this, and with the other factors, it seems to be a reasonable hypothesis that the lamp heat has been slowly damaging the plug and switch.

I am replacing those little 1895 bulbs with LEDs as well as a new switch and plug. I also figure that I ought to replace the relay and resistor since everything is apart anyway. I'll update when I'm done.

-James-

[Gromit]

One other possibility - if there is debris in your blower box creating a drag on the motor, it could increase the effective current draw through the blower connector.

My connector looked like that too and when I opened up the blower box it was full of little rolled up balls of nesting material where a mouse had set up house..

Those rodent nests are Valley Fever city so be careful and google it before opening things up without a respirator and some Lysol at least.


p.s. I just noticed you are in NC; I think Valley Fever is a western thing... but still check because it is no joke..