94 K1500 Oil Pressure sending unit Faulty?

[buck1968]

1994 k1500 5.7 -  

1) If I disconnect the fuel pump relay and the engine stops does this mean the oil pressure sending unit is faulty.

2) Can a faulty oil pressure sending unit cause a no start?

3) How difficult is it to change the oil pressure sending unit - I have read from simple to let a shop do it.

[CamGTP]

Removing the fuel pump relay would cause the truck to shut off because you stopped the fuel pump from working. Not sure how you tied that into the oil pressure switch on the dash.

 

A faulty pressure switch shouldn't cause a no start. I've seen plenty of them dead before on various trucks or where the cluster doesn't work at all anymore.

 

It's a tough to get at switch, tucked back behind the distributor by the firewall. If you remove the distributor cap you gain a lot more room. If you are mechanically inclined go for it but if not, I'd take it to a shop.

[buck1968]

Thanks for the quick response:

 

I tied them together because when I looked at the (Bishko) shop manual the OPSU appear to have a secondary line of power to the fuel pump and I also read online that it was to prevent the fuel pump from shutting down should the fuel pump relay fail while driving.

 

I am mechanically inclined, just research alot before attempting things.