Hints:

1988
Turbo

Wires come out from under the battery box area. One is orange and the other is black / red. You can see where part of whatever the orange was plugged into ripped off...

The car is a wiring mess... So many shortcuts taken by the previous owner...



Thanks!

 

ECT switch for additional fuel trim near freezing. it can be bypassed by junctioning the 2 wires. it may be related to the sub zero system as well but i have never noticed any difference whether that plug is plugged into the switch, disconnected or jumpered. so in all honesty you could probably completely disregard it.

on stock radiators the switch is located at the bottom of the radiator near where you found the plug.

 

A short jumper with make bullet connectors on each end and you're in business.

 

Sweet. Thanks. I meant to reply to this thread for a while now but forgot...

How about mystery wires #2:





Both are green/red and come out of a harness under the hood release...

Thanks in advance this time!

 

horn(s).

 

Got another one. took the intake manifold off to replace vacuum lines, change the gasket, etc... Noticed this beauty... Where should the other end be?





It is on the transmission right next to one of the engine/trans mounting bolts.

Also noticed this one on the firewall under the VIN plate:





Thanks in advance. I'm hoping to have this thing (re)started this weekend without much of the previous vacuum leak / poor idle issues!

 

basically a wire with an Eyelet connects to the bolt and then runs up and attaches to that Part on the firewall via a Spade connector on the same wire.
It's a ground.