My '87 convertible started surprising me with a dead battery from time to time for no apparent reason. I happened to be working in my garage (not even near the Vette)and suddenly the blower motor started and continued to run until I disconnected the battery. The car had been parked for several days, wasn't running and didn't have keys in it??? Temporarily, I have installed a battery disconnect to prevent this mysterious "uncommanded" blower motor operation. What is needed now is a troubleshooting/fault isolation plan so that I know where to start. I have a service manual and a multimeter and beyond those...no clue about how to trace down the cause of the spurius blower operation.
Any Suggestions Appreciated

Chiz Chisholm
Easton, MD This e-mail address is being protected from spam bots, you need JavaScript enabled to view it

Yes, this is common on them, the blower motor module is bad. It mounts in the top of the heater box. It is expensive from GM though, it is $200 and some change.
Thanks
Justin

Justin
Is the blower motor module the same thing as the "Programmer Unit" that is shown in the service manual?
Chiz