I just got my 78 in halfway decent driving condition, but after I drive it it won't let me start it back up until the engine completely cools down, which takes a couple hours
My dad thinks the issue is the coolant temperature sensor which we just replaced, the only problem is there was absolutely no wire going to it in the first place can anyone tell me where the wire that connects to it comes from?

 

The wiring diagram in your FSM (free, if you don't have one, at XenonS30 ) shows the water temp sensor wired to 2 locations - position 13 on your 'control unit' and engine ground ('earth' in 1978 Japanese/English). Someone here can probably post a photo of the connector and trace the wiring for you. Gotta get it workin' right The wiring must have been part of the orig engine harness and somebody clipped it off somewhere.

 

Yeah there's no trace of an old wire at all
Thanks I'll have to check it out
I'll update when I get it fixed

 

the s30 has two sensors for coolant temp. one is a two wire unit that goes to the ECU the other operates the temp gage.

 

Well my gauge shows the temp so it must be the one to the ecu
Thanks ill have to check and see