Oil Pressure Sending Unit?

[Shawn0331]

Looks like the previous owner removed the unit and plugged it. Am I right?

[Captkaos]

looks that way.  It that a bolt in there?

[Shawn0331]

looks that way.  It that a bolt in there?

Yes, that's a bolt... I also can't find the switch under the block by the oil filter. I'm guessing they did the same thing there too.

Which one controls the fuel pump relay and which one goes to the gauges?

[Captkaos]

Doesn't matter where it is placed but factory the pump relay is at the top where that bolt it, and the gauge is above the filter.

[Shawn0331]

Thanks. Thought so. My fuel pump and gauge/idle fuse blowing issues are all starting to come together...

Time to get a new switch and install it to cure this madness.

[Shawn0331]

My neighbor is a godsend.

Now to figure it out. Also, found a stray orange wire and two terribly frayed grounds behind the distributor.

[Emersonsdad]

There's a brass piece that goes between the switch and the block. Looks like a smoking pipe. Almost impossible to find one so I pieced one together at Home Depot. Also very easy to snap hence the reason for my trip to HD.

[Emersonsdad]

.

[Shawn0331]

Which one is where the oil pressure sending unit goes? This is above the oil filter. Maybe a source of a small oil leak?

No wires anywhere near it other than knock sensor.

[Shawn0331]

Here's the nasty grounds and orange wire.

[bd]

With the key ON and a fuse installed, touch the light brown wire you're holding in the picture to ground and see if the oil gauge drops to zero - I think that is your gauge sender wire.  Don't worry about 'popping' a fuse - that's what they're for....   

...actually, the sending unit just grounds the lgt brn wire, so you won't hurt anything.

In your pic, the orange (fused battery) and tan/white (fuel pump) wires going into the light brown connector plug into the fuel pump oil pressure switch - see pic.

The 'nasty' black ground wires are part of the ECM wiring and need to be clean and well grounded to the back of the cylinder head.

The Allenhead pipe plug directly above the oil filter caps the oil galley.  The open hole higher up is for a clutch bellcrank pivot ball.  Looks like your oil leaks are mostly from the valve covers.

[Shawn0331]

Thanks bd. I thought I solved the short by cleaning the ECM grounds and covering them in electrical tape. I also taped the end of the oil sending unit wire just because. Fuse blew again at random.

I'm taking everything out of the way this weekend to try and find the short. Also installing the switch and sending units.

So if the top of the block is for the switch, where above the oil filter does the sending unit go?

[bd]

...So if the top of the block is for the switch, where above the oil filter does the sending unit go?

Look at your pictures...

...The Allenhead pipe plug directly above the oil filter caps the oil galley....

First, verify the lgt brn wire next to the distributor is the sending unit wire.  If it is, reroute it down to the oil filter, install the sending unit and your done.  But remember, the sending unit grounds the gauge circuit, so the sender threads must make good electrical connection with the engine block (use liquid Teflon sealer on the sender threads).  Avoid Teflon tape and Loctite, because they will sometimes insulate the electrical connection.

As for your 'fuse' issue, look for any pink or pink/black wires that may be chafed.  You should also use an ohmeter and check the resistance of the AIR management valve, and EGR solenoid, etc, for a minimum of 20 ohms resistance.  Less than ~20 ohms means the device is shorted internally.

[Shawn0331]

Thanks, I'll check tomorrow after work.

[Shawn0331]

I'm picking these up today for my truck. Are these the right ones?

Sender to the gauge:
http://www.autozone.com/autozone/parts/Duralast-Oil-Pressure-Switch/1987-Chevrolet-V10-1-2-ton-P-U-4WD/_/N-iigzbZ8znc6?itemIdentifier=18884_124053_9275_5673

Switch to the fuel pump relay:
http://www.autozone.com/autozone/parts/Duralast-Oil-Pressure-Switch/1987-Chevrolet-V10-1-2-ton-P-U-4WD/_/N-iigzbZ8znc6?itemIdentifier=19001_0_9889_5835

Also, what else do I need to hook up the sending unit to the gauge? I've heard about a tube filled with oil attaching to the back of the gauge, etc.

Sorry, I know this seems stupid, but I didn't have the switches or sending units in my truck already to go off of.