Oil Pressure guage is 180 degree off

[DaveW]

I repaced the cluster that had idiot lights in an 89 with a set with guages out of an 87. With the light version of the oil pressure sensor the gauge is 180 degrees off. I used an oil pressure sensor from a 91 that had guages and it was giving reading but still 180 off of ~40. I pulled the wire and it moved to 180 off of pegged.

I remember reading about a problem with a guage reading 180 off after a swap but have been unable to find any reference again while searching.

Both clusters are pre 91 and the one sensor is 91 so they should all work correctly.
Can anyone shed any light on this?

I know that I have to replace the oil and temp. sensors but I though I would check on the 180 degree off issue before going to far. The temp guage sits just above 100 with the light version of the sensor.

[bajacalal]

I do believe you need the pre-91 (as in 1990 or earlier) version of the sending unit and you can pick it up at the local autoparts store like napa. It needs to be the unit meant for gauges as does the temp sender.

[DaveW]

Sorry, The sender from the XJ that had guages was a 90 not 91 as stated above.

If it was a 91 or newer type sender that has the switched scale would it cause the guage to read 180 degrees off?

[Runnin'OnEmpty]

If it was a 91 or newer type sender that has the switched scale would it cause the guage to read 180 degrees off?I believe it would. I do know that 91 up gauges will read that way if put in a pre 91. Using the proper sender should fix it.

[DaveW]

I still have access to the 90 and 87. I'll have to try the temp sensor out of the 90. If it move the temp guage off 180 degrees then I'll have to see if the oil pressure sensor out of the 87 works correctly. I'll know for sure if I'll have to get a new temp sensor.

[DaveW]

I have put a oil presure sender from a 87 in and it still reads 180 degrees off.

Could It be that I put one of the connectors in the back of the gauge cluster upside down? Has anyone managed to do that?
The temp and volt work correctly that may not be it, but...

[Eagle]

Could you kindly clarify what your problem is? A pressure gauge doesn't read in degrees, so you can't be talking about temperature type degrees. But the total swing of the needle on XJ gauges is only about 90 degrees of arc, so the only way for the needle to read 180 degrees off visually would be to install the gauge upside down in the cluster.

[DaveW]

The gauge is installed correctly, pressure scale at the top. The needle points 180 degrees off. That is down instead of up.

A pic is worth a few words..

With Engine Off:
http://i46.photobucket.com/albums/f141/dwpics/tmp/gauages_off.jpg

With Engine Running:
http://i46.photobucket.com/albums/f141/dwpics/tmp/gauges_on.jpg

[Matthew Currie]

I think the gauge itself is broken. I'm pretty sure it's supposed to stop somewhere to the right of 80 even if the sender is shorted.

[Eagle]

Your gauge is dead. The needle is only supposed to swing between 0 and 80. In fact, if I hadn't seen the photos, I would have said that this condition is impossible. That's why I didn't understand your question. Sorry.

Have you removed the gauge from the cluster to see if you can open it up and flip the internal mechanism 180 degrees? It appears that someone must have done that. I've never opened one up so I don't know if it can be done.

Does the needle move as the engine RPMs increase and decrease?

[DaveW]

Your gauge is dead. The needle is only supposed to swing between 0 and 80. In fact, if I hadn't seen the photos, I would have said that this condition is impossible. That's why I didn't understand your question. Sorry.

Have you removed the gauge from the cluster to see if you can open it up and flip the internal mechanism 180 degrees? It appears that someone must have done that. I've never opened one up so I don't know if it can be done.

Does the needle move as the engine RPMs increase and decrease?
I thought the needle moved when I reved the motor at first. But it did not move the last time. But I've had a couple of different sensors in it.
XJ has been stabled for a bit. I'll have to take it out for a drive.

If the gauge moved with the RPMs I'll put it and look for a way to flip it 180 degrees. If not then the search for good gauge will continue.

I was also concerned about the fuel gauge. The tank is full now but the gauge shows very full. I'll have to see how it work after some drive time.
Anyone seen one read that full?

[Matthew Currie]

I thought the needle moved when I reved the motor at first. But it did not move the last time. But I've had a couple of different sensors in it.
XJ has been stabled for a bit. I'll have to take it out for a drive.

If the gauge moved with the RPMs I'll put it and look for a way to flip it 180 degrees. If not then the search for good gauge will continue.

I was also concerned about the fuel gauge. The tank is full now but the gauge shows very full. I'll have to see how it work after some drive time.
Anyone seen one read that full?

Some of them seem to read very full when filled, but I've never seen one that went as high as yours in the picture.

[Eagle]

I was also concerned about the fuel gauge. The tank is full now but the gauge shows very full. I'll have to see how it work after some drive time.
Anyone seen one read that full?
The test for the fuel gauge is the same as for the pressure gauge. Back by the gas tank there's a plug, about 8" before the wires go into the tank. There are three wires. Black is the ground, the heavy wire is the fuel pump, the thinner wire is the gauge sender.

Turn on the ignition, but don't start the engine. Unplug the connector and see where the gauge reads. It should be pointing either to E or to F

Then take a jumper and jump the thin wire to the black wire on the body side of the connector. The gauge should now swing to the other end of the scale.

[SPVFD47]

I'd venture to say you're cluster is shot. I have a 90XJ that came with idiot lights. I found out through a friend of my dads that owns a junkyard that there are many various model clusters. They all look alike but are made for certain model XJ's based on years, engine, and particular model (Larado, Pioneer, Sport). 90 seems to be a bad year with anything dealing with the electrical systems. They seems to be a cross-bred between AMC Jeeps and DC Jeeps. 89's were built off the AMC design and 91's were completely changed to the DC design. If you got a 90 somethings were the same as a 89 and some were not. I went through 3 clusters before mine worked right. The first one everything worked fine once I changed all the sending units to the right ones. But it didn't have a tach. The second one had a tach, but was from an earlier XJ 6 cyl and my XJ is a 4 banger. So I had to use the tach out of the 2nd one and then finally everything worked fine. Turns out that Jeep didn't make clusters with Tachs for the 4cyl in 90, according to the interchange manual my dad's friend has. I noticed in the pics you have the normal style gagues, not the high line ones in the Larados and 91+ XJ's. I have the same cluster, I like the look of those more.

What you can try to do is check the resistance coming from the sensors and see if they match up with the gauges. The oil sending unit you should be using in the kind that just has a metal tab sticking up. If you have an ohm meter check the resistance at the metal tab and between a good ground. At 0 psi it should read 1 ohm, 40 psi 46 ohms, and 80 psi 87 ohms. Check the resistance and then plug the connector back on and check what the gauge reads. If you want I have the readings for the fuel sending unit also. I'd venture to say that you're gauges are burnt thou.

What year and engine do you have ?

[DaveW]

I had another cluster sitting around that I did not use because I do not know the year and the OD had a broken trip reset.
I had a trail ride the next day so I plugged in the other cluster and all the gauges worked. The gauges have a different mounting setup. So I pull the broken OD and proceed to fit the good OD into the cluster. The mounting holes are not even close. Cut a small angle bracket in two add a few pieces of a rubber gasket to make my own mounting setup and I have a fully working cluster. The oil gauge is a little jumpy but reads about the correct pressure. One day when I find someone with a mechanical gauge I'll have to check it.
It was nice to have a tach on the trail.:)
Thanks for the input. But I think the other cluster had some bad gauges.

[SPVFD47]

No, problem, thats what the purpose of this board. The oil guage in my YJ use to jump and sputer and what not. I changed the sender and same thing. Put a mechanical guage on and it did the same. Turns out the pump was clogged up a bit. Dropped the pan and strainer what was all cruded up. The oil pres sender reads the pressure on the pump outlet. If the put isn't pumping good the guage reflects it.