I just bought an '88 240. I was looking at it, and I noticed something that I shoulda caught when I looked at it...I just noticed that when I turn the key on, and all the lights come on in the dash, except for one...the Oil Pressure light.

I looked, and I could not find the sending unit. Where is it at?

 

the oil pressure sensor is near the oil filter, on the exhaust side of the block, and just behind the lower eend of the water pump.

however, odds are, the dash bulb is out if its not ligthing when you turn the ignition on.

 

It could also be the wire/connector at the sender. It gets brittle, that is what happened with mine. I put a small oil pressure gauge on the block for periodic checks.

 

yeah, that left side of the block is a prime area for small oil leaks, such as from the valve cover gasket, and oil + extreme heat (from the exhaust manifold) causes serious insulation deterioration.

 

Well, the plug is gone. So I need to buy the connection and splice it in. Where would I find one?

 

probably off a parts-mobile. not sure Volvo sells individual connectors anymore, the connector is part of the wiring harness. when they did sell the connectors, the shell and the pins/sockets inside the shell are different part numbers, and the parts catalog is REALLY hard to figure out which pins/shells are used for what.

if you do splice an existing connector's wire to your harness, I recommend using MARINE crimps, not the typical ones sold at the auto parts store... marine crimps have heat shrink insulation filled with an adhesive that melts around your wire insulation when you hit them with a hot air gun after crimping.

 

Im not sure about the fitment with your vehicle, but you could try this sender which says it fits the 240 and has a spade connector. That would make it easy to splice in a connector.

Or, you could get the original style, cut down the plastic shroud and then make your own female input. I replaced the sender on my 88 with this one and did something similar because my connector was also broken. Works very well, I insulated it with heat shrink and heat resistant tubing

 

note that one is for volvos up to 1982, with the B21F motor, they changed it in later years.