Ambient Temp Override Switch?

[CJMark]

Can someone point out the mounting location of the Ambient Temp Override Switch? Is it the front of left front fender or grille? Comes off firewall plug that also has horn and park/turn signals. Has long enough wires to reach grille. This is for ‘73 cj5 with I6 engine.
Thanks
Mark

 

[timgr]

I have seen it in Wagoneers but not in CJs.
On the inner fender there.

 

[timgr]

Note the switch had a very limited application.
Possibly '73 only - both V8 and six full-size Jeeps have it in that year.
It's not present on the '72 or '74 diagrams that I can see.
According to the Wagoneer diagrams, it is in the TCS (transmission controlled spark) circuit.
The TCS cuts vacuum advance in top gear for lower emissions (likely providing cooler combustion and lower NOx).
If you wanted, you could eliminate it and run the TCS in all temperatures.
This is what the later models do.
If you don't have a working TCS vacuum solenoid on the engine, or a working TCS switch on the transmission, the ambient switch will do nothing.
If you want to keep it, placement will not be critical - look for a suitable existing hole that's reached by the wiring.
TCS should be covered in the TSM.

 

[CJMark]

Just to close this thread out here’s some pics of the location, in the grille behind left headlight assembly. Also thanks Tim for insight on use and pointer to more info.

Interesting bit of trivia that ‘73 only year used to control vacuum solenoid then in ‘74 going to Coolant Temperature Override (CTO) switch at 160 degrees to control solenoid.