no oil pressure...still

[sluggo42]

So i replaced the sensor on the side of the block, which required quite the effort, put it all back together again, still the oil pressure guage is dead.
Is there a fuse or something electrical? I am so frustrated I feel like driving it into the ocean!

thanks for any help...

 

[Skeezix]

You are trying to get the factory gauge to work? Even when it is working it's kinda junk. Best bet would be aftermarket though. Maybe the wire for your sending unit is broken somewhere, that happened to my temp gauge, replaced the broken part and works like a charm.

 

[hvyman]

Gauge prolly fried.

Did you use a Jdm sensor first?

 

[sluggo42]

Whats a jdm sensor?
Is the stock gauge hard to get to if I just want to replace it?
Is that something that would be easy to get in the classifieds in here?
It couldn't be any harder to get to than the sensor was, could it? egads!

 

[hvyman]

A sensor from a Jdm engine. A sensor for Japan spec vehicles.

Gauge cluster has to come out and taken apart to get the gauge out. Should be fairly easy to get.

Could also test the wire with an ohm meter. Wire goes from the sensor to the body plug by the Ecu through the engine harness. And from the body plug to the gauge through the body harness.

Super simple circuit. A gauge, sensor, and a wire.

 

[sluggo42]

well the second sensor was purchased from somebody in here, but I can't remember their name. I would love to test the continuety of the wire, but after deep study of the wiring diagram, I still have no idea where the "body block" is, or what pins are being used. All I could get from the diagram was that the wire looked to be labled as "Y-8" or perhaps Y-B, but the print is so small I cant tell.
If you could give me an idea where the body block is located, I would love to test for a broken wire befor attempting to take the dash apart... But, I'll do that if needed. I'm just not the shapest knife in the drawer, and I need all the info I can get.
thanks again for the help, I wish this car was a bit easier to work on for an old retired fart like myself...

 

[jetjock]

The Y-B means yellow-back. Everything you need to know is here and on the next couple of pages:

http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=137

Also look here:

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=BE&P=37

There's at least two ways to check wire integrity. Disconnect it from the sending unit and either ohm to ground or turn the key on and check for voltage.

 

[sluggo42]

Very nice thanks!

Are all of those connectors on the firewall on the inside of the cabin, or in the engine bay? Sorry for stupid questions...:1zhelp:

Also, with the multi-meter set on ohms, do i touch the red connection to the wire attached to the sensor, and the black to any ground? And then I'll get the 42 (or whatevery it was you said)
so is it just Key on, or start the motor?

Again, many thanks. I actually feel like I'm getting somewhere due to your help, and I REALLY appreciate it.

Doug

 

[jetjock]

Meter on ohms, either probe to sender wire, other probe to ground. The key should be off. Connect the same way for voltage but turn the key on. No need to start the engine. Infinite resistance or a lack of voltage indicates an open circuit.
Or you can briefly touch the wire to ground and see if the gage moves.

Connector D is on the rear of the cluster, connector M is near the ECU, and connector L is the sending unit.

 

[sluggo42]

Nice work Jet !!

Thanks to your invaluable help, I have identified that I have about 12v at the iol pressure sensor with the key on. This confirms that the gauge is faulty.
It worked when I took the car in to a repair shop for a head gasket job, and when I got it back, it didn't work. He denied having anything to do with it, and challenged me to prove that it was even working when I brought the car to him in the first place. I have no idea if he could have done anything that would have fried the gauge, but I am convinced he caused the gauge to fail somehow. He was a jerk from the get-go, and I will never go back to him. Unfortunately I was stranded at the time, so I had no choice, and was too deeply along by the time I figured out he was worthless in many ways. The car has run well since the job, so his mechanics were ok, just the owner... But, still.... forgive my ranting..

Now, comes removing the dash??? I guess I better hit the search button again..

thanks again mate,

Doug