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1965 Plymouth Valiant oil pressure sensor

I recently installed a new alternator and battery in my 1965 Plymouth Valiant 200 (225 engine). When I started the car after completing the task, the oil prssure light came on and remains lit. I did not touch the sensor when replacing the alternator. There is no wire attached to the sensor and I cannot find any wire discounnected anywhere near the sensor, nor anywhere else under the hood. What gives?

Are you sure your looking at the correct sensor? The sensor works by grounding the wire from the light when the pressure is too low. Perhaps the wire is connected to a ground somewhere, making the light go on.

Thanks for such a quick responce. The sensor is attached at the oil filter housing and it has what appears to be a place to clip a wire, but there are no wires in sight. I looked at the engine from a 64 Valaint and there is indeed a wire hooked up to the sensor, but the sensor is mounted on the block on that engine. I went to a parts place to look at the sensor to make sure I was looking at the right part and it matched; unforunaetly they have no diagram for installing it and I can’t find anything on the internet to show how it’s hooked up. I need to find someone with the same year and engine as I have to get a certain observation.

There is a wire SOMEWHERE that connects to the sensor…is this car new to you? Has the light worked normally in the past? For the light to be on, the wire is now connected to a ground…

I’m unsure of your 65 …but a 1975 Aspen did NOT illuminate the light when disconnected. It remained off. The switch on that model year grounded out when pressure was low. A friend destroyed hers by hearing noise on the highway and not wanting to stop. The wire was unhooked.

I found it odd, but that’s the way it worked.

This doesn’t mean much to you, you just need to find the wire, or its remnant, and put the proper clip on it.

I’ve owned the car for about seven years now and it worked fine until that fateful day when I changed out the battery and alternator. There are no wires anywhere near the sensor and I climbed under the car to see it there was a loose wire there. I there are a number of Valaints around town, I’m going to flag down the next one I see and look at their sensor and hopefully get an answer. Thanx

I had a similar problem (years ago)with my 1965 Dodge Dart 273 V8. My wife said the light came on while driving at 30 mph. She immediately stopped the car and phoned me. I checked the oil level and it was full. The shop was not far away so we dropped it off.

The mechanic said the oil light had SHORTED OUT and the bulb stayed on. Oil pressure was fine too. When you start the car, the light would come on temporarily to indicate it’s working. Your problem may be similar.

Certainly sounds similar, my oil pressure is good and my oil level is full. Becuase the problem I fixed was the alternator and battery it could be a short, but were and how to locate it. It may be time to take it to my friendly mechanic, or cover it up with duck tape LOL.

A good mechanic can fix this problem very quickly! The electrics on a 1965 Valiant are stone age simple compared to today’s cars.