Heater motor keeps going?

mickey356 · 01-23-2010, 05:50 PM

I got out of my car tonight and I noticed a sound coming from the engine compartment after I'd turn the car off. I popped the lid and it was my heater blower motor. Drove around a bit more hoping it was just a fluke thing, but it wasn't so I took the engine compartment fuse box cover off and pulled the fuse, which stopped it of course, and popped it back in. It seems to have solved the problem for now, but can anyone help me out here? What would cause that?

Hendog · Hendog's Garage

[QUOTE=mickey356;5143152] and pulled the fuse, which stopped it of course, and popped it back in. It seems to have solved the problem for nowQUOTE]

So, to be clear, you removed the fuse (which one?) and the fan stopped. Then you put the fuse back in and the fan did not start up? is this correct?

My Bentley maual doesn't cover 1983, but in the '84 the brown wire from the ingine fan goes into the alternator then to ground. The other side to the fan has a yel/red wire going to the fresh air blower switch. The manual does not indicate a fuse (I'm looking at an '84). You must have a current leak, obviously, but can't help more than that for now.

VaSteve · 01-23-2010, 06:49 PM

It runs if the heater levers are pulled up a bit. It's supposed to stop if they key's removed. Did it still run after you removed the key?

mickey356 · 01-23-2010, 07:29 PM

Hendog,
I pulled the bottom fuse (yellow) and yes, it stopped and did not start up again after I put the fuse back in.

VaSteve,
I did not remove the key but I did push the heat levers down to see if that would stop it and it did not, the motor keep going. That said it could be that I never pulled the keys out. I'll see if I can get it to do it again and see if removing the keys stops it.

Thanks for your help.

cary · 01-24-2010, 07:24 AM

Should only have power with the key ON. Levers have micro switches on them.
Has someone tinkered with the wiring?
I use mine to cool down the engine after AX runs. Keeps it from heat sinking.

RShepHorse · RShepHorse's Garage

I've been trouble shooting the nonworking heat system on a new to me '84. I finally figured the problem had to be inside the Engine Compartment Heater Control Unit. I found a bit of a surprise. The circuitry involves a jumper on the back side of the circuit board that carries juice from the main engine compartment blower relay over to the spiral around the reed switch... suffice it to say, this thing had nearly melted off, had swung down and had come in contact with another part of the circuit. Maybe you have something like that going on? I believe there may be always-on power going into that controller.

[I'll post a shot of the fried board.

RShepHorse · RShepHorse's Garage

Red Bar is where it should be, green arrow was where it headed.

86 911 Targa · 08:05 PM

Are your footwell blowers also running?

For some reason, one of the relays in the Heater Controler is latching up.

And, do you have a source for a replacement relay?

Changing out the relay from another car might might
resolve the issue.

The '86 P/N with Auto Heat, is 911-618-153-00

Good luck,

Gerry

DRACO A5OG · DRACO A5OG's Garage

So did you ever find the ghost in the Heater Blower?

I too have intermittent running of the blower after shut down but key in the "on" position with out levers being activated.

DRACO A5OG · DRACO A5OG's Garage

Found my culprit:

Here: Running fan after engine is turned off?

When cold she she would stay on for couple of minutes then shuts off