Oil Pressure Gauge Issues...

[quadracerx]

Hey Guys...

My flatbed truck is the combination of a 1979 GMC Chassis and a 1984 GMC cab... The original cab was too rusty so I made the change to the 1984 cab which has power everything...LOL

I assume after some research that my Oil Pressure Gauge is electronic not mechanical? Right now its pegged at over 60. I assume the wire may be grounded somewhere along the way?

I haven't taken the dash bezel off yet, hoping I don't have to...

1) Can anyone tell me what color wire is supposed to be connected to the gauge?
2) where the possible locations are for the sender(s)? Its a 454/Turbo 400...
3) Where the wire(s) might come through the firewall?

Thanks in advance for your help... This board is an amazing group...

 

[80sHottrodder]

Im not sure about on a 454, but on my 350 the sending unit is behind the intake next to the distributor. My gauge was doing the same thing and thats what it was.

 

[PrairieDrifter]

if I remember correctly it’ll be in the same spot as a small block. Right by the distributor behind the intake.

My 84 has a tan wire to the oil pressure sending unit, and it goes into the main engine bay harness.

You’ll have to match the sending units to the year of the cluster for accurate readings. So if your sending units are from the 79 chassis and engine you’ll have to update to the 84 model. You’re temp sending unit and your oil pressure sending unit will have to be changed.

 

[PrairieDrifter]

Also taking the dash bezel off isn’t as big of a deal as it seems. Less than 10 screws and a couple little things to move and a little bit of patience and care are required to not break stuff. Mainly the cluster housing is all you gotta watch for, the bezel itself is pretty strong.

 

[Jerry phillion]

If I remember right, to ck if the elec oil pressur gage is good, turn key on and touch tan /or gray wire to ground and if good ,needle
Will go to "0". Gauge should work with oil sending unit , which is connected to engine block above oil filter area.

 

[bucket]

Right, should be a tan wire and the gauge should zero out if the wire is grounded. However in a big block, the sender should be in a port at the lower left corner of the block, right behind the power steering pump area.