electrical problem

[gpete]

My heater blower will not shut off even with ignition turned off. I pulled the fuse and still will not shut off unless I disconnect battery. Could it possibly be a stuck relay? Thanks. Greg

[boyt911sc]

Originally Posted by gpete

My heater blower will not shut off even with ignition turned off. I pulled the fuse and still will not shut off unless I disconnect battery. Could it possibly be a stuck relay? Thanks. Greg

Greg,

What model year car do you have?

Tony

[gpete]

1986 911

[steely]

first let me say I am not a Porsche heating system guru. (It isn't an intuitive system :-)
This is for the heater blower on the engine?
Do you have Autoheat (round dial on console aft of parking brake and no red levers)?
Which fuse did you pull o/o curiosity?

Would any of this help?

blower-fan-engine-compartment-wont-turn-off

911-3-2-how-does-heating-system-work

[T77911S]

you are making think about something I have not thought about in a while. this hurts.

I assume you have the auto heat.
you have 2 fuses. one for L and M and another for hi. you also have a relay for hi.
relays don't usually stick. the hi spd relay is under the passengers foot board. try removing it If the fans are on HI.

if the fans are on low then the main sw in the controls is bad. in the link it would be the top one in the diagram. this is the one that goes bad and runs the fans all the time, although not sure how it runs the fans with the key off. even with the heat on and key off the fans should not run.
sounds like you may have the power to the heat controls wired to something that has power all the time. I would suspect at the fuse block.

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/941050-auto-heat-foot-well-blowers-part-deux.html

is this car new to you?
if not have you recently done some wiring work?

I will have to think about the heat controls some more.

[gpete]

Hey guys. Thanks for your help. I'm guessing I don't have auto heat because I do have the 2 levers coupled with like a 3 speed rotary switch between the seats. Yesterday I pulled every fuse in the fusebox one at a time and the blower still kept running. Pulled the relays one at a time also and that didn't work either. The switch that controls the blower seems to be operating properly as I can still adjust the speed. If you've got any ideas pass them along. Thanks again. Greg

[RDM]

The blower has found some other source of 12V power. I'd look for pinched wires and the like.

[T77911S]

that IS auto heat.

the switch WILL still control the fan speed if the "main" power sw is bad.

the sw goes bad and is ON all the time. this provides power to ALL fan speeds but the default is low.
take a look at the link I posted. the first drawing has a red wire with "12v" on it. that wire is probably wired to direct power and is not fused.

you can try to lift the carpet behind the center console and disconnect the power although I am not sure if you can get to it without removing the console. there may be a cardboard cover over it.

[86 911 Targa]

pm sent.

Gerry