Knob under the dash by the hood release

[pantera928]

My 1980 has 2 toggle switches and a rheostat type knob near the hood release. One switch is for the power antenna. One is for the power door locks.

Any idea what the knob does?

Thanks

[64studeavanti]

Perhaps fader for rear speaker.

[pantera928]

1 minute ago, 64studeavanti said:

Perhaps fader for rear speaker.

Could be but someone has installed and aftermarket unit in the glove box so who knows.

Thanks

[Kodjo]

My '69 Avanti has a defroster fan on the rear window. The switch is a 3 position rotary swtich neer the hood release.

[Jim78]

Just a guess here...  Possibly someone replaced the dimming resistor for the dash lights with a rheostat.  This would affect the brightness when the overhead switch is in the first position.

[R2W55]

If it is connected to a potted box, Turn on your wipers and see if it acts as a variable speed for them.  I have one that does that.

[pantera928]

1 hour ago, R2W55 said:

If it is connected to a potted box, Turn on your wipers and see if it acts as a variable speed for them.  I have one that does that.

Well, the build sheet says it has intermittent wipers but it does not seem to and the knob does not seem to affect them. It has one speed and if you turn the wiper knob further clockwise, it seem to act like a rheostat and varies the speed a little

Doesn't seem to affect the dash lights either