Gauge problem?

[cutter404]

When I bought my 89 S-15 Jimmy The oil pressure was fine but it sat for a long time then i got it cranked and now when its cranked it goes down to zero and a check gauges light comes on what could this be.

[Teaman3]

Possibly something serious, possibly not.

First, check the wiring to the gauge.

Loosen off the pressure tap at the side of the oil filter and start the engine. If oil sprays out, you've got pressure. Run the engine for NO MORE than 20 seconds. Best to have a friend to help.

If you have pressure, then the sender unit is failing, so you'll likely have to bend some plastic for a new one.

If no pressure, then the oil pump is failing. You'll have to remove the sump to get to it.

I'll be surpised if it is the pump, but they can fail. More likely to be the sender and/or wiring (internal break).

You should also check the connection to the flexi circuit mounted on the rear of the console box. On several makes of cars, I've found this to be a weak point.