[79 Phoenix]

I am working on installing new engine and front lighting harnesses on my 71 base GT-37. I can't tell from my shop manual what the two plugs below connect to:

1)The first and second pictures below show one that has a BLACK AND DARK BLUE wire on top and on the bottom side something attached that looks like it is wrapped in black plastic. Can anyone tell me what this is for?

2) The third picture is actually bright ORANGE. Does it plug into the middle prong on the Horn relay?

[johnta1]

I would say the #2 is for the horn relay.
The #1 I'm not sure, but could be for the TSC switch? But I've never seen that kind of connector from the factory? Looks like aftermarket?


But there is a dark blue and black wire that goes to the TSC switch with the blue going to the temp switch and the black going to the tranny.
Maybe follow the wires to see where they go?

[79 Phoenix]

Originally Posted by johnta1

I would say the #2 is for the horn relay.
The #1 I'm not sure, but could be for the TSC switch? But I've never seen that kind of connector from the factory? Looks like aftermarket?


But there is a dark blue and black wire that goes to the TSC switch with the blue going to the temp switch and the black going to the tranny.
Maybe follow the wires to see where they go?

Yes, that's what it's for! I found the switch on the old engine... I'm not sure how relevant it is these days but I guess the TCS switch is supposed to regulate the vacuum between the carb and vacuum advance... Not sure it's worth trying to make it operational..

Do you think I could just bolt the switch to the new engine and plug the wires into it but just not hook up the vacuum lines?

There is a TCS switch on the trans that the single black wire plugs in.

[79 Phoenix]

I found the TSC switch on the old engine, cleaned it up and bolted it on the new engine attaching plug from new wire harness. I will not hook up vacuum lines. Thanks for the help!