What is this knob for?

[EvilManor]

I don't have any pics, but I have black knob connected to what looks like a stainless bracket with a cable mounted under the center of my dash.

I've tried pulling and twisting the knob but it doesn't seem to do anything. It won't pull out but will turn endlessly.

Any ideas?

[Double D]

Valve to let coolant flow to the rear heater core?

[EvilManor]

Valve to let coolant flow to the rear heater core?

Would it control coolant for the front heater core too?

[Double D]

Not sure - I don't see why you would want to ever cut that off. Does your front blower put out heat with the valve shut?

[Scary Guy]

Maybe a dome light switch? But usually that pulls out. Still the wires make me think differently. If it was a screw I'd think that something was mounted there but that would be kind of obvious.

Basically, we need pics.

[EvilManor]

Not sure - I don't see why you would want to ever cut that off. Does your front blower put out heat with the valve shut?

No but I think I have another issue there as I don't get any air coming through the vents.

Maybe a dome light switch? But usually that pulls out. Still the wires make me think differently. If it was a screw I'd think that something was mounted there but that would be kind of obvious.

Basically, we need pics.

I think it pulls out as it looks like a cable housing of sorts. I'll get a pic this evening.

[spastic_chicken]

Manual Choke?

[LMS]

That's the self destruct button.....apparently it's broken.

[pyro]

Push it up and turn. Watch the trip odometer. It should be the reset button.

[SarahtheSweet]

turbo boost button?

[EvilManor]

OK finally got some pictures



Here's the bracket (pic from underneath)


Cable? going through firewall

[SarahtheSweet]

Manual choke to carb?
or selector cable to heater door?
Where does the other end of the cable go?

[EvilManor]

Manual choke to carb?
or selector cable to heater door?
Where does the other end of the cable go?

Those were my thoughts to, but which one. The cable goes through the firewall just under the glove box, but I haven't been able to locate where it comes through the firewall in the engine compartment to continue to trace it.

I'm thinking maybe it has been cut or broke and isn't going to its intended location....which might be why the knob won't pull out.

[Double D]

yeah, i still think its to a heater hose valve - look for a spot in the hose that has been cut and and had a "T" installed with a second hose attached to it leading down and underneath the car and then back up into to the attendant compartment. You should have a secondary heater core down there with a cage blower mounted behind it (visible from the driver's side under-beir compartment door)- it may be be stuck closed at the valve and that's why the knob wont budge.

[SarahtheSweet]

Mine is a 69 superior I don't know if the MM are the same
but I have a pull knob on the left of the steering column under the dash that operates the rear heater hose valve on the driver's side fender well. (goes to the three hose setup)

It also has a heater hose cutoff with pee cock valve just as it comes out of heater core,(passenger side) but no cable to it.

There is another cable that goes to the heater door and mount against firewall to the center towards passenger side, but inside it is in the slider for heat/cool thermo control.

Mine also had a divorced choke electric set up on the original quadra jet carb. So I don't have manual choke pull knob.
From other older vehicles I have had in the past the manual choke setup is usually mounted under or in dash to the right of steering column.

Mine also has dual pull selectors in each kick panel for cabin floor vents.

Take a look under the heater box on the firewall and see if there is signs of where a cable went thru... Hope this helps and doesn't add to the confusion, Maybe?