Engine Temp
This is what it says in the Hotwire Auto install guide that they emailed me:
15. Open Wires (wires vary by harness options)
a. Red 12 Volt Hot at all times. (direct to battery)
b. Pink 12 Volt Run and start. (ignition key on position)
c. Yellow Ignition start. (ignition key cranking position only) You must use the included starter solenoid wiring for the engine to start properly. (Mopar muscle cars: You will need to use a momentary push-button starter switch with this wire on one post and 12v on the other post, the dual ignition circuit of a late 60s to early 70s Mopars will not work with the Hemi system)
d. Blue Brake light output to rear brake lights.
e. Purple Backup lamp output to rear backup lamps.
f. Orange Overdrive off Switch to momentary ground. (optional, automatic only)
g. Blue/White A/C compressor clutch. (12 volts to activate compressor)
h. Black Clutch safety ground. (manual trans) This must be grounded in when the clutch is pushed in or in Park/Neutral on a non-electronic transmission.
i. Green Speedometer output to gauge.
j. Grey/Black Oil Press Gauge (open on both ends for you to hook up your own sending unit)
k. Tan/Black Engine Temp Gauge (open on both ends for you to hook up your own sending unit)