Hi All:
I am in a quandry, (and without heat or AC), about this problem.

A few weeks ago the control unit, (button unit), started smoking and melted it's cover while the circuit board burned out.

I secured a new one and it worked fine for two days until this morning when it also "Melted Down". I did notice a high pitched noise from the unit as it smoked away.

The major damage is the circuit board totally burning up below the "Overall Ventilation" push button. The case melted and actually burnt a hole below the circuit board failure.
All the buttons melted internally and are now frozen.

Does anyone have experience with this problem? Any thoughts or suggestions?

I really appreciate any help you may offer.

Thanks, Ron Young

I have been told that a dragging blower motor can draw enough current to melt down the push button unit. I believe the only other high current device powered though the unit is the auxiliary water pump. Did you have the correct fuse installed?

That reminds me I wanted to check all my fuse values in both my cars' fuseboxes.
Anyone ever take the time to color code the little chart in the lid of their fuse boxes so as to quickly verify visually that the right fuses are in?

These fuses are weird in these cars; they seem to protect not only against catastrophic failures like a shorted motor, but also against that seasonal "pull" or something.
My 1991 300TE's blower motor fuse melted on its own this spring.
I'm thinking, wow expensive part, and here it's a $1.50 fuse link; they call it a strip fuse.

__________________
Bob Roe
Lehigh Valley PA USA
1973 Olds 88, 1972 MB 280SE, 1978 Datsun 280Z, 1971 Ford T-Bird, 1972 Olds 88, 1983 Nissan Sentra, 1985 Sentra, 1973 230.6, 1990 Acura Integra, 1991 Volvo 940GLE wagon, 1983 300SD, 1984 300SD, 1995 Subaru Legacy L wagon, 2002 Mountaineer, 1991 300TE wagon, 2008 Murano, 2007 R320CDI 4Matic 52K, some Hyundai, 2008 BMW 535xi wagon, all gone... currently
2007 Honda Odyssey Touring, 2014 E350 4matic

Thanks for the inputs. The blower seemed fine, but I will check it out. I was wondering about the auxillary pump. I had the temperature control set to max cool until this morning and maybe the unit tried to run the pump.
I never checked the fuses for size. I will do this tomorrow for all of the fuses. Who knows what a PO put in there.

I was looking at the description of the control unit and there appears top be what is refered to as a sloid state unit. I need to locate it and inspect it also.

I fear this may become a very expensive problem with two costly button units melted already.

Thanks again,
Ron Y