Some years ago I took my 1989 Mazda 626 to an airconditioning repair shop and they removed the fan resistor and lost it. New ones were about US$60 but I managed to buy a secondhand one at half the price. Now that one has packed up.
A few of questions:
Where is the damn fan resistor located? I can't remember where it went last time. The workshop manual I consulted shows it only on the wiring diagram.
What are the specs for the fan resistor? (Ohms, wattage) Since the one I have doesn't work it's no use measuring it.
Why are they so expensive? Surely they are just glorified resistors, which I could buy from my local electronics shop for a few dollars, if I knew the specs for it. Since Google shows 13,500 references for "fan resistor", this is obviously a very common problem. Why don't they make them a bit more robust? (excuse the rant... :)
In that part, you got took. They lost it, they buy it. End of discussion there. You allowed them to charge you for their negligence. When a mechanic screws up and loses/breaks/otherwise "forces" a replacement, it's the shop's responsibility to put things right. But, that's "some few years ago", as you say, so probably not worth trying to pursue.
In the 79-82 626s, it's inside the ductwork, on the plate just above the blower motor itself. (good design, IMO - If thy're in use, they get hot. Having them right there in the airstream, before anything that's going to raise/lower the temperature, they get the blast of air to help keep them from burning up.) There are three of them (corresponding to "low", "medium" and "high") and unless things are different than the quick glance indicates, they must all be replaced as a unit.
You say the replacement has "packed up"... That's not exactly the most detailed or helpful trouble report I've encountered. Does the fan work on one speed, but not another? Does it not work on one speed, but the others are fine? Does it just plain not work at all?
You may not be (and I tend to think this is the case, based on the severely limited information you've given) looking at a failed resistor at all - possibly nothing more than a connector has come loose somewhere. What's the evidence/behavior that points you at the resistor (resistors, actually) as the source of trouble? Without that, I'm just shooting in the dark.
Assuming you even knew where it was, eh? :)
No clue for ohms. Ballpark figure for wattage: LOTS.
No, they're not your typical electronics resistors. Once you get to them, you'll find that they look like three sizes of spring - just naked coils of stiff wire riveted to their connectors, and standing there in space. The question is, what kind of wire, to achieve how much resistance. The answer, at least from me, is "dunno".
For an '89 it's under the dash, on the passenger side towards the kick panel. Should be four bolts and drop down.
It's resistor wire. I got some extra life out of one by soldering the breaks back together. But this was fairly short lived as the other wires started breaking and then the same ones in different locations.
mazda part. Only answer I can give.
It has coils of resistor wire for each setting. My guess is all you would need is resistor wire of the same gage to refurb one.
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