Ambient temp. Switch

[Bulldog]

Guys cananyone tell me what this ambient temp switch does on an old car or ford truck numbers say it is on old cougers and mustangs, mine was on a 1972 ford truck it shorted out and burned wires up in the dash.it mounted on drivers door jam and had 2 wires on it .thought some of you cobra and ford guys might know what part it played on such and old. Truck. Thanks. Bulldog will try to send Pic

[spdbrake]

From the F100 Website forum:

"Door jamb sensor on 1972 F100
Sorry guys I didn’t see this post earlier. Art is right, that is an ambient air thermal sense switch for the emission control system. Lighter duty trucks and all cars from that time period were saddled with this system. The thermal switches are similar throughout the years but the control system that it is hooked up to went through several names and changes.

Basically the system controls emissions by NOT allowing any vacuum advance to the distributor unless the vehicle is moving at least 25 to 35 mph OR the outside air temperature is below 50 degrees. The earlier system used a speed sensor spliced into the speedometer cable and an electronic control module with a solenoid valve. The later system used a transmission switch to signal high gear and an electronic amplifier with a modulator valve.

I can help you troubleshoot the various evolutions of this system if needed.

Not very exciting after all.

Barry"

And also a link to the thread: https://www.ford-trucks.com/forums/7...tml#post494508

[Bulldog]

Spdbrakethanks so much for the info. On the sensor the guys at the ford house didn't know. What is was even with the ford number on it . You were the first person to know what part it played on the truck thanks again. Bulldog

[MaSnaka]

Sounds like a government control system. Disregard and bypass. Good call on SPDBRAKE.

John

[Bulldog]

Masnske that's what I did wired around it thanks guys Bulldog