67 heater switch question

[mikec35]

I am doing work on my car and the I have the heater control panel just hanging. I tried to turn on the heater blower and it would not come on. I moved the whole panel and it touched the dash, sparked and the heater blower started working. My question is: Does the heater control panel have to be grounded for the heater blower to work, or do I have some sort of wiring problem? thx..

 

[67GTFB]

Mike --

According to schematics I have, +12Vdc/battery is fed to the blower switch via the 19945 connector. Then the switch routes the current to the resistors in the blower housing for blower speed selection, then on to the blower motor and eventually to chassis ground (near motor I suspect). The sparking was probably caused by some "hot" (exposed) piece of the switch assembly contacting the dash (which is chassis ground). But I'm at a loss to explain why the blower started working unless your system was re-wired (backwards??) some way.

Good Luck!!

Scott

 

[67coupe351w]

The switch provides the ground for the circuit.

It must be grounded to the dash in order for the blower motor to work. The spark was from you bringing it in contact with the ground when you had the switch in one of its on positions.

 

[mikec35]

Thanks for the info! Mike