Anyone have some wiring diagrams for Merc Topaz heater controls? These things are notorious for burning push button switches. I have a factory shop manual and can you believe not ONE wire color or useful drawing. 100 bucks for nothing. They refer you to a EVTM manual for those drawings. Which is not included in the shop manual of course. And the dealer doesn't have access to anything older than 1994 on his computer system.
Geez.
TIA
Hello, I think i can look for old wiring diagram maybe 92's if that's fine with you
Hello, I think i can look for old wiring diagram maybe 92's if that's fine with you
Sure. Would appreciate it. I did find a bit of info on Autozone and was able to temporarily bypass the defective switch so I can get the heater fan running. It still does strange things like start the rad cooling fan when the windshield is set to defrost. This is really weird. Is it possible to somehow be connected with air conditioning? Is it standard to have the rad fan cut in when the air conditioner is started? I know the assembly is somewhat charred so perhaps there is a short across from air conditioning to defrost.
Anyway there is heat again so this isn't a panic situation any longer. Eventually I hope to find a good used part in spring when I browse the junk yards. I haven't got the wiring figured out for the rear window defrost but that is less important. I will be away for next two weeks too.
For the rad cooling fan.... whenever any heater position that has air blowing on glass is selected, the AC cycles to act as a dehumidifier to reduce/eliminate fogging. Whenever AC is commanded, the radiator fan will come on in order to draw air across the AC condenser (without this airflow, the AC would be ineffective since the refrigerant wouldn't condense to a liquid).
In my '97 Contour, the A/C would come on in defrost mode only below a certain temp, about 10 or 11 C. So the A/C might not come on at certain temps on the Topaz, as well.
Jeff
Wow. I didn't think of that. It seemed odd but it sure makes sense now.
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