[87vettconv]

Is anyone familiar with the electroic air conditioning system on an 87 convertible. I recently purchased the car and the evaporator and blower motor come on intermittently when the car is not running. This eventualy runs the battery down.

Is the problem a sensor?

Is it normal for the system to operat when the car is off? If it is could the problem be related to the system no being charged?

any help diganosing the problem would be appreciated.

 

[Patrick]

Welcome to digitalcorvettes! :buhbye:

I'm sure someone will jump in here and help you with your problem.

:thumbsup:

 

[AlfonsoGomez]

Weird your case is, as Master Yoda would say. I'm no expert but it seems the A/C system is taking current even with the engine off. I would start by checking the wiring that feeds into the system. Probably a cable going "live" intermittently. When you find out what is causing this very weird problem post the results for everyone to see. Good Luck.

 

[War Machine]

Do you know how to go into diagnostic mode on the A/C?

If so did you get any error codes?

 

[87vettconv]

I checked the wiring. It looks okay and problem can not be repeated or stopped by wiggling the wires. I thought the control unit might normally run when the car is off to reduce condensation (etc) I know some other cars' electronic tempeture contols do that. I can tell you that the problem occures both with and without the dash contol unit connected and the unit is not tripping codes.

thank you or the suggestions

does anyone have any other ideas?

 

[FiberglasMD]

Electronic AC controller (the thing on the dash) can go bad. Most of the time it is the case that the buttons don't work or work intermitent.

 

[87vettconv]

Finally got around to fixing this problem. It turned out to be the blower contol unit. Just for general knowledge if you have a problem with the blower motor running when the car is turned off it is probably this part.