1984 C-10 Silverado CCC help

[Donnylee]

Hi guys,

I recently bought a 1984 stepside. Has a transplanted rebuilt 69 350. Where I live we have sniffer laws so every original smog piece remains on the truck.
It just passed sniff no problem. But I have kind of a baffling problem that appears to be related to the choke light and signal. That I want to sort out.

There is a 3 wire harness coming out of the firewall. Plug has been cut off. The wires are two light blue, one light yellow. It appears they have tried to run these to a 3 wire sensor that is on the oil pressure side front of the block with three wires coming out from the sensor.

The firewall wires appear to have 12V, a Ground, and I assume the yellow goes to the Computer for feedback. If I hook these up my choke light on the dash simply stays on. When you check the sensor it does not have continuity bewteen the 3 terminals not running...you start it, it does with oil pressure. And then of course it triggers the choke light inside the cab.

I am thinking this sensor is not correct for whatever it suppose to do, and seems bizarre a choke signal would be monitored off oil pressure.

I am hoping someone can help me identify the method of operation of this so I can get it hooked up correctly, or confirm that the sensor is in the right place to begin with, or when it should be open/closed state on the switch....

At this point instead of pulling all of this smog off, I want to make everything correct and work again. And this has me stumped.

Thanks for any guidance here, I believe this was a California emissions truck to begin with. But this sensor and its correct operation is a mystery I am hoping someone can clear up for me.