Wiring Diagram or wire colour help please??

[Turdle]

Yeah, the other way--ground the gauge wire you disconnected from the sender, then turn on the key

 

[blueka]

ok, gotta run back to the shop... brb


Si

 

[blueka]

made no difference... but, if the pins aren't lined up to power that circuit... then I wouldn't get a reading either way anyway, would I?


Si

 

[blueka]

forgot to mention that when I turn the key, the gauge will move off the bottom post but not register on the scale.


Si

 

[Turdle]

Ok yes, the pins must be in the correct location for the circuit to be complete. Sorry I butted in I guess.

I still want to see if the sender itself changes state when the engine is running though.

 

[blueka]

sender doesn't appear to change state when engine is running... showed open circuit when engine was off....

So, hopefully, if I can get some power to this circuit, then I can alleviate my problem...


Si

 

[Turdle]

Sounds like the oil pump is bad Simon.The sender will switch without power to it, as it is a pressure switch.

It should switch low when the engine runs.



It could be the oil pump is not turning. Removing the cam sensor cap will let you see if the sync drive is rotating/ just have someone crank the engine with cam sensor cap off.

The cam sensor drives the oil pump.

 

[blueka]

I'll check it again after supper... measure twice cut once...


Si

 

[Turdle]

when you do, try all the all of the "ranges" on your meter. If the resistance is higher than the range selected on the meter it will display an open circuit value.

 

[blueka]

I had it on the bottom one, there's not a whole lot of room in the engine bay now.... need hands like a 5yr old...

Si

 

[Turdle]

If you had an extra harness you could rig a test lead up.

do you have an alligator clip?

Oh, is this the brand new sender or one you used from another truck?

 

[blueka]

this is the known good one from my SOHC V6, I wish I had a good harness too, then I wouldn't have those ugly battery terminals on my harness... I prefer the OE ones.. .


Si

 

[blueka]

nope.. No change in state..

Si

 

[Turdle]

OK. now you need to back up and make sure if the oil pump is giving pressure or not.

First thing I would do is check if the cam sensor is turning.

 

[blueka]

well, I'm guessing that I've got pressure, as, the tappets are quiet, and with the amount I've ran it since firing it up, it hasn't seized up.

Where is the cam sensor?


Si

 

[Turdle]

I wish someone else would jump in here and offer ideas. seriously. I don't want to lead you on a wild goose chase but to be honest I would not assume anything with a used engine.
You need to be sure you have oil pressure.
Yes an engine can run quite a while with no oil. ever see those cash for clunker killer videos?

the lifters are roller lifters. They make little noise.

The reason I want to see the cam sensor is I have read many times of the drive gear shearing off. This will cause no oil pump drive, and no pressure.

The cam sensor is under the coil packs. It looks like a tiny distributor with a small wire connector.

I think the top bolts for it are 6mm--there are 2 of them, and they are kinda long for what they do. . just take these out, move the cap aside, and have a helper crank the engine. You want to see the silver thing under the cap rotate.

an other thing you could try--
get a 4-6" long brass nipple with 1/8 npt ( i think that is the size) threads, heck, Just Match the threads on the oil sender.
Get a cheap as you can find mechanical oil pressure gauge. Find a fitting adapter to fit the gauge to one end of the nipple. Screw the other end of the nipple in the oil sender hole. Now you have a fool proof oil pressure gauge to check oil pressure with.

 

[blueka]

ok, cam sensor turns when I crank the engine..

We're not able to check the oil pressure with a physical gauge tonight... no parts...

So what next?


Si

 

[Turdle]

well, it is "possible" something is blocking oil flow to the sender.

You "might" try unscrewing the sender, stick a length of hose into the hole, and see if starting the engine gets oil pumping out the hose --be sure to have a catch can and shut the engine down when the oil squirts out. If there is a blockage there this will possibly clean it out.
Then look at the sender unit--check the little hole for blockage.

You need to be sure of oil pressure before proceeding IMO.

 

[mecman99]

OK in a pinch and I don't do it this way myself I use a gauge . you can do this, pull the oil pressure sender and make SURE it won't start have some one bump it over or crank it over for a few seconds and see if oil squirts out of the sender hole ..it will make it bit of a mess but.. Personally i would make the gauge work and then go from there. Not a big money fix use a meter or a continuity light for a temp oil "light"..just to see if the sender works

 

[Turdle]

Here's another test to try.

find a fitting which will fit an oil sender and allow it to be exposed to air pressure from your compressor.Heck, even some duct tape "should" work for this.
Use an alligator clip to ground the sender by the threads. So, in other words the sender is removed, but hooked up. You are using air to pressurize the sender.

Connect the sender to the truck's harness, switch key to on. Hit air pressure to the sender and see if gauge jumps up.