Mystery Switch

[leftlane]

I was in the cab of the 87 and happened to look under the steering collar and noticed a togglle switch at the bottom. I traced the wires and found they went to the ECM temp sending unit. Why would someone put an on/off switch on this sending unit. I found the wire was pulled apart under the hood so it wasnt doing anything. I called the man I bought the truck from and he knew nothing about the switch. That means it has been there "unknown" for at least 10 years. Any ideas would help me with this one.

 

[norcals91]

Maybe an on/off switch to a auxiliary gauge. I had one on my gauges cuz I didn't like how bright it was at night.

 

[leftlane]

Its not another gauge, It was wired in as an on/off switch. I do have an aftermarket temp gauge on it but it comes off the other side of motor. So i know that wasnt the case

 

[dave2575]

It could have been a on/off switch for an electric fan with a temp sensor kit installed were the ecu temp sensor is located, idk. I have seen stranger, like a switch installed for a 2nd keyed ignition, and a switch to power the on /off button for the a/c. People do weird s#!t to there trucks.

 

[leftlane]

I dont know what it was, I removed it and wired it back like it was supposed to be. I guess I will see when she comes out of the garage if there is any difference. I have a neighbor that retired from FORD and ask him about it. He told me that some people done something like that so they could fool the ECM into making the truck run richer. Whether it worked or not I dont know, I do know I dont need it richer, that just means more time at the gas pump. I dont know I just know that it is gone now. THe wires were pulled apart anyway so it wasnt doing anything other than bypassing that sending unit, see what happens in a few weeks.