Oil Pressure Sending Units and/or Machanical

[GOPAPA]

Where do you start/end -- and with and what do you use to install a machanical oil pressure guage system.

Where do you start/end --and with and what do you use to install a electrical (dummy/idiot light) system?

Where do you start/end --and with what do you use to install a electrical system showing pounds on a guage ?

Feel Free to Correct me on any of the above .. because correct information will not only help me ,,but help anyone who searches for the right answers .. gp

[El Jay]

I'm not exactly sure what you're looking for, Larry; but I'll tell you what I've done in the past & hopefully it'll help.

On my boats, I ran electrical gauges. SW gauges with matching sending units. They power went through the gauges & grounded through the sending units.
At the block I came out of the oil galley with a 1/8" NPT nipple into a 1/8" NPT tee. Put the sending unit on 1 outlet of the tee and a mechanical gauge on the other outlet. That way if I had any problems with the in dash gauge, or wanted a verification reading, all I had to do was holler at somebody in the back seat to look at the mechanical gauge.
You can skip the tee & the mechanical gauge & just thread the sending unit into the block.
Don't use any thread sealant on electrical sending units.

On my Chevy I run a mechanical set up. Come out of the oil galley with a 1/8" NPT nipple and then adapt it to an 1/8" line with a ferrule fitting and plumbed through the firewall to the gauge.
You need to make a couple of "circles" with the tubing to allow for flex because the engine moves around/torques over. You don't want that line to case harden & break.

I can't help much at all with the warning light question. The only warning lights I ever ran were on my VW sand buggies & that was over 35 yrs. ago. As we know, the memory is the second thing to go.

Later, Amigo.

Larry

[GOPAPA]

LJ ,,this is exactly what I was wanting ,,a full discription of the parts with a detailed path of how you hooked up a machanical oil pressure line to a guage..


On my Chevy I run a mechanical set up. Come out of the oil galley with a 1/8" NPT nipple and then adapt it to an 1/8" line with a ferrule fitting and plumbed through the firewall to the gauge.
You need to make a couple of "circles" with the tubing to allow for flex because the engine moves around/torques over. You don't want that line to case harden & break.
LJ

Now If others here on the forum will do the same with idiot light details that tells us when the oil pressure is low and how they hooked it up and all..
And another electrical oil pressure guage hook up is one that the guage shows the lbs pressure that the motor is running at. This one hooks up down by the oil filter ..

Recently I have gone to the search forum and found lots of answers to electrical and along with it I found out who wrote up good posts and replies and therefore I was able to private mail these wise folks and get even more answers I needed .. Theres always something about our trucks that we dont know ,,but others do and to put it in the search forum then we all can know .

I really hope this continues as the younger folks that carry on our love for these trucks will for sure be able to use it. gp

[VetteVet]

Well anybody mind if I chime in?

There are 3 types of gauges for the oil and water temp gauges, and they work very similar. The first is the Mechanical oil pressure gauge which EL JAY gave an excellent description of what to use and how to plumb it. It';s pretty simple really. Oil pressure is routed through the small tube and the pressure moves the needle on the gauge according to how much pressure the oil pump is generating.

Then there is the electric style which uses a variable resistor sender that is calibrated by resistance to ground. The oil pressure varies the senders resistance to ground which is sent to the gauge and is read much like the water temperature gauge. Each resistance value of the sender is reflected on the gauge as oil pressure.

The third type is just a simple warning light AKA idiot light. It works like a pressure switch and as the engine oil pressure drops to a low value the sender switches to a closed circuit to ground which turns on the light in the dash.

The routing of the wires from the senders runs from the engine compartment and goes through the firewall to the dash cluster. The diagram below shows which wires go where in the different type dash. we only have two types of dash clusters in our trucks, The gauge cluster and the idiot light cluster.
This is the plug that connects the senders to the gauges in the cluster.

This is where the wires go into the plug for the dash with gauges.

This is where they go for the idiot light dash.


The oil pressure sender is by the coil but it is actually located by the distributor and has a dark blue wire running to the dash. The water temperature sender is mounted in the left cylinder head or in the intake manifold by the thermostat, and it has a dark green light going to the dash .


There are also three types of water temperature gauges that can be used. The most common is the electronic which also reads variable resistance to ground. Then we have the thermal type which you see in the aftermarket kits. They use a temperature probe in the cylinder block that routes the signal through a tube to the gauge in the dash. Our trucks don't come with these from the factory that I know of.
Then we have the idiot light style that just turns on a light in the dash when the sender grounds and closes the circuit for the idiot light.

[stich626]

I'm gonna guess that you are asking because you have the light and want the gauge? correct..
you can have both..
if no gauge and don't need it to be stock. go electric..
mechanical brings hot oil into the cab..
leaks get messy...

[GOPAPA]

Originally Posted by stich626

I'm gonna guess that you are asking because you have the light and want the gauge? correct..
you can have both..
if no gauge and don't need it to be stock. go electric..
mechanical brings hot oil into the cab..
leaks get messy...

Thx ALL 3 OF YOU ..Now thats,,what Im talking about..

I have the guage and the blue wire coming out of the fire wall electrical block and ,,now I need to know where exactly I install the electrical sender at that I wire up to the blue wire .I have a 402 engine and I see a place by the oil filter ,,but not sure if thats the place or not ..

[VetteVet]

You can use the port by the oil filter but the factory uses the one in the picture by the distributor. The yellow arrow is pointing to it. If you wanted to run a mechanical gauge also you can just run a Tee off the port and tap into it.
Just make sure you use the right sender for the electrical gauge and not the one for the oil pressure idiot light.

[GOPAPA]

Again great diagrams,,explaining.. VetteVet,,this all will be really helpful in the search Forum ..

I do not want a machanical set up ,,or idiot light ..I will go the electrical guage as thats what is in my cluster.. gp

[VetteVet]

Considering the size of the sender, you may want to put it in the port by the oil filter. Be sure to plug the one by the distributor

[48richard]

Great thread. I am thinking about hooking up the oil warning light in my Camaro tach as well as my mechanical gauge, and also running my electric choke through an oil pressure switch as the factory did later on. I worry about having that great big sender hanging off a T by the distributor, so using a different location (by the filter) makes sense to me. Anyone have a picture of that port location?

Richard

[VetteVet]

center of the pic over the filter.

[48richard]

Thank you!

Richard