I was trying to trace a possible short in the heater and AC circuits and couldn't find it, but what I did discover was that the blower motor would run for 10-15 seconds and then go off and then maybe it would go on again and do the same. I found that if I tweaked the red three-prong plug that goes into the heat/AC switch the blower would respond. When I took the plug off I found the center spade of that connection loose on its rivet on the switch. I tried to carefully solder it tighter but when I put the switch back in the dash, I got nutin'. When I took the switch out and checked continuity, I could get no connection with any of the three plug spades either with each other or with either of the two center spades while pushing all the buttons. The only continuity was between the two individual spade terminals. So...
Do you think this switch is toast?
Do you know of any diagnostics for the switch? It's not in the '70 manual that I can see.
Does it matter which center spade gets the light green (power?) wire (and which gets the blue)?
And since the AC isn't hooked up under the hood anyway, can this switch be used as is for the heater and defroster by just shunting or bypassing some wires?
Any ideas? Thanks.
(modified:)
Does the vacuum have any connection to the electrical contacts? That is, does the switch work without the vacuum lines hooked up?
