Hello, I finally installed the heater in my car. I have the non ac heat control in the dash . How do you shut off the blower fan? Nothing on the control shuts it off. just low, med & high speeds. Yes i replaced the resistor, fan motor & used the factory wiring. Nothing on the slide selectors shuts it off either. I have to be missing something.
non ac control head
- Thread starter carl
- Start date
- Status
What year is your car?
Our 78 Cutlass is the same, no option to shut the fan off.
In summer I unplug the blower motor under the hood right on the heater box.
I'm sure it wouldn't be too difficult to wire in a power switch to the motor.
Our 78 Cutlass is the same, no option to shut the fan off.
In summer I unplug the blower motor under the hood right on the heater box.
I'm sure it wouldn't be too difficult to wire in a power switch to the motor.
The ignition is your only factory on/off switch for the blower motor in your car.
I had heard from a crusty old mechanic at my old GM service garage that they kept the blower motor on to minimize starts/stops of the fan for electrical reasons. Starting/stopping is hard on electric motors. This is true, at least for AC powered pumps in which I have some experience in. But I find it hard to believe it is a concern for a lightweight DC fan, though. But what do I know? This is simply anecdotal, no evidence I have found to support or dispute.
Someone told me once years ago it was for making sure the resistors had air flow to cool them down after heater use, but that doesn't make much sense because if you turned it off, they would no longer be energized, so they would naturally cool down.
I had heard from a crusty old mechanic at my old GM service garage that they kept the blower motor on to minimize starts/stops of the fan for electrical reasons. Starting/stopping is hard on electric motors. This is true, at least for AC powered pumps in which I have some experience in. But I find it hard to believe it is a concern for a lightweight DC fan, though. But what do I know? This is simply anecdotal, no evidence I have found to support or dispute.
Someone told me once years ago it was for making sure the resistors had air flow to cool them down after heater use, but that doesn't make much sense because if you turned it off, they would no longer be energized, so they would naturally cool down.
Government mandated. It was a federal law starting in the late 60's that required all car makers to have the fan running enough to pull outside air in at all times.
Makes the most sense. So they could continue their crap quality builds and allow leaky exhaust to enter the cabin and attempt not to kill anyone by carbon monoxide poisoning.
Except it must have been a mandate in the 70s because my 71 has an "off" for the fan. So did the old 72 442 I had. Cuz when it's off, it's off.
I have a few panels with & with out the molded in block in what would be the "OFF" position. Some cars did come with the ability to turn off the fan. I think one might of been done be the car's owner.
- Status
Similar threads
