Heater Blower Motor problem - Electronics - Third Generation F-Body Message Boards

Jim_e_d · 07-07-2008, 03:52 PM

Hey everyone. I have a 87 T/A and I've had problems with the Heater/AC Blower staying on after the ignition is off. I've replaced the switch, and checked the coils in the airbox under the hood. I'm not finding any messed up wiring. It shuts off after pulling the fuse in the fuse box.

When the switch is in the HIGH position, the blower stays on for about 15 seconds, then shuts off, but shuts off immediately on the lower fan speed settings. I'm thinking that this is part of the problem I have with a power drain on the car, causing the battery to die.

Now that I've relayed everything, Can anyone help me out?

Thanks
Jim

BigBabyLou · 07-07-2008, 04:50 PM

On the High setting, the power is sent to the blower through a relay. It sounds like the relay is sticking.
You can try opening the relay and cleaning the contacts with sandpaper, they'll be likely burred and burned.
The blower relay is located under the hood, passenger side. Detailed location in the picture in this thread: http://www.thirdgen.org/techboard/co...er-heater.html (Blower for heater)

Hope this helps.
Lou

Jim_e_d · 07-07-2008, 06:25 PM

Hey Lou, thanks for the info. I checked the relay, and even replaced it and the same problem. The blower motor stays of for about 15 seconds after turning off the key. I pulled the fuse to see if it was isolated on the blower motor circuit...We'll see what happens I guess.

BigBabyLou · 07-07-2008, 07:17 PM

I would put a test light (or voltmeter) on the relay to see what exactly is going on there. Specifically the orange wire and then the purple wire. I'd be curious to know myself.
http://www.austinthirdgen.org/mkport...C60_manual.jpg

Do you have an alarm? Is it possible that it is hooked into the blower system?

Lou