Jump to content

Gauges from '89 XJ no worky in my MJ


Recommended Posts

Bought these a couple months ago: viewtopic.php?f=24&t=22122

 

Been putting my '88 Pioneer back together and put these in in place of my idiot light cluster, but used my old speedometer/odometer so mileage was correct. Also swapped the clear lens since the one I got had paint all over it. Installed the gauges and started the truck - tach works. Speedometer works. Oil pressure, volt meter, and fuel gauge do not work. I don't expect the coolant gauge to work because I have not yet installed the proper coolant temp sender, but I HAVE installed the right oil pressure sender.

 

Pulled the cluster back out and reseated the two wiring harness connectors a half dozen times or so. At one point, I think I got the volt meter to work and the oil pressure gauge was giving me a reading, albeit very low and there was no pressure increase with throttle increase.

 

With the exception of the tach (and maybe the voltmeter) the gauges seem completely dead. Seems odd that all of the smaller gauges are being very iffy. Is there a ground somewhere I'm missing? Anyone have any suggestions? Is the '89 XJ cluster simply not compatible in my '88 MJ?

Link to comment
Share on other sites

Carefully pulled the prongs out in hopes for better contact with the cluster. Tach and volt meter still work and I thought I was getting a little life out of the oil pressure gauge, but was wrong. It seems to stay around the 0-10 psi mark and makes very minimal movements with changes in engine speed. I doubt my oil pressure is that bad as the engine runs pretty smooth with no knocking. I have a mechanical oil pressure gauge I can use to check, but I need to dig it out. I also swapped in the right coolant temperature sensor and I'm still not getting a reading on the gauge. Fuel gauge isn't doing anything, either.

 

The fuel gauge on the original cluster worked and the oil pressure and coolant temperature sender were both confirmed working before I swapped them into this truck. I'm thinking the cluster is no good...

 

Oh, I also checked ground connections and cleaned them up...no change.

Link to comment
Share on other sites

Is the printed mylar circuit board on the back of the cluster torn, scratched, etc? Check closely, espec where the connectors plug into the cluster.

 

Yes, some of the connectors are a little scratched up - probably from me constantly removing and reinserting the connector. I looked all over for spots where it may be torn or there is a discontinuity in the circuit and couldn't see any. I suppose I could check with a multimeter, too.

Link to comment
Share on other sites

I am having exactly the same issue with my oil pressure gauge. The rest work fine. As I posted up in a separate thread about an hour ago I attempted to adjust my low oil pressure gauge and broke the dang thing off. Now may have to go new cluster. Might try some sort of epoxy or jb weld solution before I go new cluster. Tried superglue but it didn't work.

 

Keep me posted on what you end up doing and I will do the same.

Link to comment
Share on other sites

My understanding is that the oil pressure and temp sending units work by applying variable resistance to ground, therefore if you disconnect the wire at the sending unit, put it to ground, the needle should peg, indicating your gauge is working.

 

When I disconnect the oil pressure sender wire, I noticed that the gauge pegged to the right. I didn't try it with the coolant temperature sender. I will try this when I get home from work. Still need to figure out the fuel gauge....it's just completely dead.

Link to comment
Share on other sites

My understanding is that the oil pressure and temp sending units work by applying variable resistance to ground, therefore if you disconnect the wire at the sending unit, put it to ground, the needle should peg, indicating your gauge is working.

 

When I disconnect the oil pressure sender wire, I noticed that the gauge pegged to the right. I didn't try it with the coolant temperature sender. I will try this when I get home from work. Still need to figure out the fuel gauge....it's just completely dead.

The crude "go - no go" test for the fuel gauge is the same as the others. Unplug the connector with the ignition on -- that's an open circuit (infinite resistance) -- the gauge should peg to the right. Jumper the connector to a good ground, bypassing the sender -- that's zero resistance, the gauge should bottom out to the left. (I may have the left and right reversed, I can never remember without looking it up).

Link to comment
Share on other sites

Here is what I did this weekend:

 

1) Hooked mechanical oil pressure gauge up. On a hot engine, I'm getting about 12 psi at idle and around 40 psi at cruising speed. I'm not thrilled with the idle oil pressure, but I'm going to first change to a higher quality filter (there is currently a Fram on it) and some decent oil. My Dad used the cheapest of the cheap when he did oil changes on this thing.

 

2) Grounded out the coolant temperature and oil pressure sending wires. I should have wrote this last night as I already forgot which way the needles pegged when I put the wires to ground, but I do remember that both gauges were consistent and pegged the same way.

 

There was a very brief period of time where I saw the oil pressure gauge operating and it seemed to be fairly accurate with what my mechanical gauge was showing. After I jiggled the cluster and seated it in it's place, the gauge went back to it's old self reading a static pressure with no changes as the engine speed increased or decreased.

 

The cleaned the coolant temperature sender wire and pinched it a bit because it was sitting kind of loose on the sensor. That gave some life to the gauge, but it's reading around 120-130 degrees. I know the engine is much warmer than that using my infrared temperature sensor.

 

I've ordered a new oil pressure and coolant temperature sender. If they're not the problem - well, then I have a couple of spares :)

Link to comment
Share on other sites

Ditch the FRAM filter immediately!

There are many threads on this board as to why. Don't let your Jeep become a statistic. :fs1:

 

Believe me - I will. I've done my research on these filters and I know they're crap. My father insists on using them on all of his vehicles despite the information I provide him. Only reason that the FRAM is still on is because my RockAuto order with 10 Wix filters got lost in transit.

Link to comment
Share on other sites

I wouldn't even try to diagnose a oil pressure issue with a Fram filter in place.

Doing away with the Fram eliminates a major possible culprit to some of your oiling situation.

 

I just poked and prodded FedEx as to my RockAuto order. That's all it took as it suddenly has found its way back onto a truck and is en route to my house. Guess I should have done that the minute I saw that it spent more than 24 hours in one of their sorting facilities...

 

Anyway, should have a Wix tomorrow and I'll do a full oil and lube on it and report back. Should have the replacement gauge senders Wednesday or Thursday. Gotta love RockAuto...plus I get free magnets with every purchase!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...