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Swaping in a newer gauge set 97+ ?????


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I would like to know if anyone knows if I will be able to swap my old gauges out for the 97+ gauges. I would like to know if I can go from analog to digital does the spedo pick-up go straight from the speed sensor to the gauges or does it go through the computer then gauges. If anyone knows for sure please let me know. This is in a 87 MJ that I am swaping the complete dash out of.

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you won't be able to operate the 97+ dash and interior electronics (you need the 97+ wiring, and all the 97+ sensors, intake, etc. for it to work. otherwise you're gonna have a heck of a time wiring it all to work.

 

I believe everything 97+ is positive ground.

 

also, the heaterbox, and vents, are different between the two.

 

want to fill us in on your intentions? this seems to be a very vague question you're making.

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you won't be able to operate the 97+ dash and interior electronics (you need the 97+ wiring, and all the 97+ sensors, intake, etc. for it to work. otherwise you're gonna have a heck of a time wiring it all to work.

 

I believe everything 97+ is positive ground.

 

also, the heaterbox, and vents, are different between the two.

 

want to fill us in on your intentions? this seems to be a very vague question you're making.

 

Correct except for the + ground statement. Also the 97+ XJs are OBDII, so you will need an entire wiring harness and a PCU swapped in too. Plus sensors. Big job.........

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Correct except for the + ground statement. Also the 97+ XJs are OBDII, so you will need an entire wiring harness and a PCU swapped in too. Plus sensors. Big job.........

ah, sorry...it's not the normal sensors that are + ground, i believe it's thefuel tank sending unit which is + ground. or some other wiring thing, i can't recall, but IIRC the wires are switched or something along that line.

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Correct except for the + ground statement. Also the 97+ XJs are OBDII, so you will need an entire wiring harness and a PCU swapped in too. Plus sensors. Big job.........

ah, sorry...it's not the normal sensors that are + ground, i believe it's thefuel tank sending unit which is + ground. or some other wiring thing, i can't recall, but IIRC the wires are switched or something along that line.

 

Yes, the polarity reversal for the fuel senders started in the 1991 models.

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So hornbrod. If I got a sending unit for my 88 out of a 91 comanche the gauge is going to read backwards? Will everything work normal besides that? PS sorry bout the JACK. :oops:

 

Here's an old NAXJA post from our very own Eagle. Sounds reasonable to me. Yet others say you MUST use the correct sender for your year, either the 86-90 or the 91-92. I don't really know, but in eyeballing the schematic I see no reason why the newer sender won't work if you reverse the potentiometer wires. But it will not be completely accurate because the pot ohm values are different (88 vs. 105 ohms). Maybe Eagle will chime in in this.

 

Chrysler reversed the polarity of the gauge sending units in 1991. The fuel pump may have the same part number, but the fuel level sender does not.

 

Just reverse the wires. Except there are only three wires ... one feeds the fuel pump (that's the fat wire), one feeds the sending unit, and the black is ground for both the pump and the sender. Best way to do it is to pull the fuel pump out of the tank and reverse where the wires connect to the sender.

 

The gauge will be slightly inaccurate because the old sender had a range of 0-88 ohms and the new one has a range of 105-5 ohms ... but the fuel gauge isn't exactly 100% accurate anyway, so you'll probably never notice.

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Eagle - Lifetime Member

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OK I needed to add that I have the complete dash assembly. I will be going back out to get the heater assembly. I will be starting to test the wires on both gauge assemblys and I think I will be doing it the hard way that means tracing down every wire in the 97+ gauge cluster and matching it up to the older gauge wires. If anyone has a link to what they think might match up with what I am doing please feel free to post it. Thanks

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OK I needed to add that I have the complete dash assembly. I will be going back out to get the heater assembly. I will be starting to test the wires on both gauge assemblys and I think I will be doing it the hard way that means tracing down every wire in the 97+ gauge cluster and matching it up to the older gauge wires. If anyone has a link to what they think might match up with what I am doing please feel free to post it. Thanks

 

97+ XJs are on a BUS system controlled by the computer. Mating the two wiring harnesses together will be almost nearly impossible.

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correction, it WILL be impossible. you need the entire 97+ wiring harness, and the mounting for the dash is different.

 

the heater box is also different, so you can't use yours. same with the controls for it, and your vent tubes.

 

 

this is a much more detailed swap than you're thinking...I want to do it, but I hesitate simply because i don't know if I can do the custom wiring (not to toot my horn or anything, but you are talking to someone who's retrofitted and wired a motor into his comanche...after deciding that I didn't like any of that engine's factory wiring)

 

good luck.

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I'm going to hop in here and ask a question. Could you order another wiring harness from a company like Painless wiring for a 97+ cherokee and then switch in the dash? I realized it would be expensive to order a whole new harness but just asking for curiosity. Thanks

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I'm going to hop in here and ask a question. Could you order another wiring harness from a company like Painless wiring for a 97+ cherokee and then switch in the dash? I realized it would be expensive to order a whole new harness but just asking for curiosity. Thanks

 

...not really. the wiring isn't really the issue. it's all of the connectors, sensors, and IIRC (may be wrong) the gauges are run from the engine computer...which means that you need the entire engine bay wiring harness as well.

 

best bet, get aftermarket gauges and make a panel for them that mounts where the 97+ gauges go.

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I am thinking that if I spend the time tracing the gauges wires to the connector and trace the ones I have in my truck it should work. I know this will be very time consuming but even if I have to install aftermarket gauges in the 97+ gauge cluster it should work. I work with electronics and tracing wires to there respective gauge and connecting to the 88s wires in theory it should work. I know even if I have to swap sensors out the wires should still go from point A to point B.

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I am thinking that if I spend the time tracing the gauges wires to the connector and trace the ones I have in my truck it should work. I know this will be very time consuming but even if I have to install aftermarket gauges in the 97+ gauge cluster it should work. I work with electronics and tracing wires to there respective gauge and connecting to the 88s wires in theory it should work. I know even if I have to swap sensors out the wires should still go from point A to point B.

 

the theory would work...if the gauges ran off of the same pulse or whatever, but they don't. polarities are reversed, and sensors are different. the 97+ sensors route through the ECU first, then to the gauge cluster after being interpreted.

 

you can do this, but you'll need to make some bypass modules or something along those lines.

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You are thinking in the wrong direction. Its not going to work, the electronics are on a completely different scale. The 97+ gauges are completely computer contolled 100%. The computer tells the whole cluster what to do. Without a computer input they will read "NO BUS" and won't do anything. Your older model senors will not have the right signal to run these guages. If you get new sensors from a 97, they won't work either because they are designed to relay to the computer what is going on.

 

I ripped apart my 98 XJ when it was a cut up trail rig and was installing autometers. I learned a lot from it..

 

Best bet is to rn aftermarket gauges like in the picture above. Or swap complete wiring harnesses/sensors.

 

EDIT: and ditto what JeepcoMJ said....

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