1989 Reatta Blower Fan won't cut off

[Posti]

My 1989 Reatta heater blower fan stays on even when the ignition is turned off.  You have to unplug it on the firewall connection.  Is there a relay that controls this?  I suspect it is stuck open.  I have ordered a shop manual and owner's manual, but it will be a week or so before they arrive.  Any assistance would be appreciated!

[DAVES89]

There is a blower control module on top of the firewall taht has two connectors going to it. In Ronnie's tutorial section it discusses that. He also has the replacement units in his store.

[Ronnie]

I agree with Dave. The Blower Motor Control Module is probably the problem. What you describe is a common failure mode. It is labeled as a Power Module in the photo below.

[Posti]

Thanks for the information. I'll put that ont he list of things to buy! At least the car was cheap. :grin

[Ronnie]

Thanks for the information.  I'll put that ont he list of things to buy!  At least the car was cheap.  :grin

 

They are expensive. If you like to rummage through salvage yards you might find a good used one. I think other Buicks with automatic climate control used the same blower module but I don't know which ones.

 

There is a Reatta owner working on a way to rebuild the modules but I don't think he has perfect the process yet.

[Posti]

I picked up the module today for $6 at a local Pick n' Pull self-service yard. Turns out most big GM cars with electronic climate control used the module from 1985-1993. Mine came out of a 1987 Cadillac DeVille and worked great. One problem down!