I took out the heater from my 1949 chevy 3600 to try and figure out the wiring. Under the dash I have a dial labeled heat that was wired to the ignition and the picured toggle switch and then had a wire attached to nothing. The toggle switch was attached to the heater and turned the heater on. What is the correct wiring? I have been unable to find a diagram.
Check Old Online Chevy Manuals website and look under 1951 accessories and it gives installation instructions for the heater. Not much to it. chevy.oldcarmanualproject.com will get you there. My setup uses a switch, off-low-high, vs the toggle but I suppose a toggle would also work but only give an off-on connection.
Last edited by Forty9; 06/20/20215:13 PM. Reason: More info
Looks like the original heater switch broke and someone added a toggle. You only need one switch. Test the original to see if it works and replace or use the toggle. Either way it's just an on-off switch for the fan motor and the wiring is:
1. Wire from the "ON" terminal of the ignition switch to one side of heater switch. 2. Wire from other side of heater switch to motor. 3. Probably a good idea to have an inline fuse between ignition and heater switch. 10 amp. 4. I believe the original switch was a variable resistor type. Increasing speed of motor as you turn knob. 5. I've seen talk of a toggle switch used for the defrost. Probably referring to deluxe vs Standard. Not sure about that info.
The "ON" terminal of the ignition switch is the one that is only hot when ignition is on.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
