This two-prong switch behind the distributor and intake manifold. Its called the oil pressure switch, right? What is its purpose? It looks like it has a few wires going to it but I havent traced them to a source. As far as I can tell it doesnt have the potential to keep the engine from running and it doesnt go to a gauge either. I can't seem to find any information about it online but if its not completely necessary I may take it out and free the engine bay of some more wires and just run a gauge straight to that port.
Oil Pressure Switch purpose?
- Thread starter Chillin014
- Start date
Pretty sure the switch your talking about is the 2 prong switch oil pressure switch for the electric choke. Should be a red wire from drivers side that runs to it, and a blue or green that runs to the choke
Hmm I had no idea it went to the electric choke, maybe that's why my electric choke has never worked. I will definitely take a look at it and probably replace it. Thanks.
Originally the factory wiring has the electric choke being fed from the oil pressure sender.
If there is no oil pressure-the choke gets no power.
As soon as there is pressure-the choke gets power.
Reason why? All I can figure is assume you turn the key to the on position but do not start the engine right away. If not for this switch the choke would open before its time to. I don't know who or why you'd do this though.
Anyone else know, or think, anything?
If there is no oil pressure-the choke gets no power.
As soon as there is pressure-the choke gets power.
Reason why? All I can figure is assume you turn the key to the on position but do not start the engine right away. If not for this switch the choke would open before its time to. I don't know who or why you'd do this though.
Anyone else know, or think, anything?
Electric chokes on quadrajets are VERY common to burn out if the key is just turned on. Therefore, it gets no power if there is no oil pressure. Makes sense to me but My car still has a quadrajet and the oil pressure sending unit but it's a 1 wire unit and all of my wring diagrams only show a 1 wire. Either for an idiot light or a for a gauge....
malibu101 said:
That's correct. It's so the choke doesn't start to open until after it's been established that the engine is running. There isn't enough oil pressure during cranking to energize the choke heater, but as soon as the engine starts the pressure gets high enough to close the pressure switch & energize the choke heater. If I remeber correctly it's also part of the "bulb check" feature that lights to indicate choke heater continuity when the key is in the "run" position with the engine "off". The "oil", "choke" or "engine" light should come on. If it doesn't, the choke heater or the "gage" fuse is bad. If the light stays on after starting it indicates loss of oil pressure, loss of voltage at the choke heater or a blown "gage" fuse. One wire pressure senders are for the RPO UF7 & RPO U14 gage package oil pressure gage or for cars with divorced choke. The sender should be on the driver's side of the block between #1 & #3 exhaust ports for Chevy 90* V6 & V8 & under the #2 exhuast port just above the oil filter on LC3 engines.
The cars with gages & electric choke also have the normal 2 wire connector for the choke heater. It's by the distributor or on the front of the passenger side of the block on LD5 engines.
Tommy
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