Nearly done! Another little question.

I've got all the engine bay wiring done except for the coolant temp sensor. (the one at the lower left of the radiator). I'm assuming this runs to the ECU and the stock gauge?

Where is the harness for it? I would guess it's on the battery harness but I can't find it anywhere. I'll check the FSM again but I couldn't find it once.

Also, my reverse lights are always on when the car is in run. Did I hook something up backwards or do I need to swap the reverse light switch? Which one is it?

 

No, it's a temp switch for the emission controls. I wouldn't even bother connecting it. The ECU's thermosensor is on the back of the water pump housing, and the the temp gauge's sender is on the rear plate under the oil filter next to the oil pressure sender.

Wiring diagrams page 50-26, connector F-37 on the Front harness.

It's just a switch so swapping the wires will do nothing. You're probably got the fifth gear switch and reverse switch wires mixed up.

 

It's a part of the Front harness. Page 50-28 of the free, online Factory Service Manual shows where it is routed to and what harness it belongs to . One wire goes to ground and the other to pin 1H of the ECU.

Page 50-120 shows the ground points on the car. That water switch uses gnd point (6) of JC-01, which is located below the Trail coil assy. Actually any good chassis ground would do for this critter.

EDIT: I wrote the above prior to NZ's post above. Just a little slow hitting the send/save button.

 

There's two colored sets of wires at the reverse/over the top switch. On the cars I've seen, there are two red wires and two green wires.

So you take a meter and put it on ohms. Put the transmission in reverse. See which pair of wires has continuity. That is the reverse switch wires. The thing to know, is the reverse set of wires gets 12vdc going to it from the Front harness. The Fifth gear switch gets NO power to it. The fifth gear switch just puts a gnd on a wire of the ECU when in fifth gear. And the split air solenoid also if memory serves.

I remember NOTHING about the connections from the switch wires to the Front harness. Just make sure the connector on the front harness has 12vdc on one of the wires.

 

I'm wondering if the previous owner clipped the wires because there is NOTHING up there that I can find on the front or battery harness. Good to know that I don't need it, thank you

I was guessing that switching the wires wouldn't help, but wouldn't the lights turn off when I put the transmission in 5th if I had those switched around? I have an extra transmission complete with sensors so I'll mess around with that one.

 

Looking on the "battery" harness (actually called the Engine harness) won't help coz it's not there.

It comes out of the Front harness underneath the battery tray. It's two wires taped togther ending in two bullet connectors.