98 TJ electrical issue (gauge cluster dead)

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hillstrubl

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1998 TJ that recently had a very dead battery. It would start and run (albeit a bit rich) just fine with a jump. When it was revved a bit or after a while of charging the gauge cluster would come back to life. After the latest jump it hasn't woken up. The battery itself has been replaced with a brand new one, charging/holding the charge fine (alternator is fine), but the gauges are dead. We pulled the gauge cluster and found that the pins for both constant and ignition switched power are both dead.

So the gauges themselves might be fine?

Anything else we can look at?
What "feeds" the gauges? The ECM? If so wouldn't it have issues starting running?

The whole dash is apart. No codes at all from the OBDII reader. Gauge cluster doesn't respond to self test at all.

  • Power at fuse 10 (Labeled instrument cluster) inside block with ignition on
  • No power at fuse 17, inside block, key on or off
  • Gauge cluster's C2 blue plug pin 8 switched power is dead, pin 9 constant dead
  • Under hood light and courtesy lights have power (apparently they are on the fuse 17 circuit)

Tried to manually give power (and ground) to C2 plug pins to see if the gauges did anything, but not sure that's actually a test of anything.

Questions:
  • Why is there no power to the gauge cluster (needles, etc) when fuse 10 seems fine and is fuse 17 involved at all?
  • IF fuse 17 was the source of C2 pin 8 (switched) or C2 pin 9 (constant) and its dead at the fuse box, then why are both pins dead at the C2 plug?
My hypothesis is that the gauge cluster itself is fine and the problem is earlier in the circuit. Why I don't understand is why does fuse 17 seem dead, but things powered by it are fine?

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Hi, I'm troubleshooting this with the OP as well. Fuse 17 was at the fuse panel behind the glove box inside. No power, constant or when keyed to ignition. Fuse 17 in the box under the hood, fuse is good. Didn't test for constant/keyed power there yet.

Underhood light has power, driver side courtesy light has power. Gauge cluster connector C2 (Blue) no power at pin 9 or 8.

Cluster has no power to even try the self test. All the past threads mention cluster going dead intermittently, but this issue seems different to the common TSB issue where airbag light illuminates then gauges go dead.

The lights for turn signal, high beam, parking brake, and backlights when headlights are turned on, all operate. It is the gauges themselves and the odometer that stay inop.

I also soaked and scrubbed both gauge cluster connectors and wiring loom connectors with electrical cleaner. Cleaned all fuses.

@Jerry Bransford - was told you were the guru to poke on this issue. :)
 
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Still trying to fix this, the biggest issue is that the only (perceived) dead area of the fuse box (fuse 17) seems to have accessories off of it that work.

https://fuse-box.info/jeep/jeep-wrangler-tj-1997-2006-fuses-and-relays
I just discovered that the instrument cluster appears to be powered from a relay that I believe is then powered by the fuse box (fuse 10?). Part number is RY-116. What if the relay got fried somehow but the fuse/power feeding it is fine? Any idea where this particular relay is on the car?
 
had the exact same thing on my 97. tried cleaning, twisting the pins, re-soldering the cluster conections for 2yrs. must of pulled that cluster 50 times. sometimes when driving it would come to life, sometimes it didn't. might work for a week or 2 then go out for a month. i had ordered a new cluster on e bay for $65 but sold the jeep before it arrived. good luck, i just kept my gas full and drove it. it was a 4cyl. so no way i was going to get a speeding ticket !
 
tr21triton said:
had the exact same thing on my 97. tried cleaning, twisting the pins, re-soldering the cluster conections for 2yrs. must of pulled that cluster 50 times. sometimes when driving it would come to life, sometimes it didn't. might work for a week or 2 then go out for a month. i had ordered a new cluster on e bay for $65 but sold the jeep before it arrived. good luck, i just kept my gas full and drove it. it was a 4cyl. so no way i was going to get a speeding ticket !
Click to expand...
The problem is that we can access the 2 power pins on the C2 plug successfully and aren't seeing anything.
 
luckily my brother is the electrical wizard and all mine checked good. we would put everything back together and it might or might not work for awhile before dying again. we were down to either the cluster or pcm being the problem. i like it alot more when shit just dies !
 
Some updates from @djbrand1 today.

Number 3 underhood had no fuse in it. It's marked fog LPS

Put all new mini fuses in 3, 10, 12 behind the glove box.

All new mini fuses underhood.

No power at right courtesy lamp
No power at this fuse (see needlenose below)

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No power at the 20 above it
 
KEEP IT FULL, MAYBE CARRY A FULL GAS CAN IN BACK. DONT PASS ANY COPS. SOMETIMES DRIVING MINE IT WOULD GO BEEP BEEP BEEP AND THE GAUGES WOULD START WORKING
 
i could tear mine apart, plug it in and it would work fine. put the trim back together sometimes it would keep working sometimes not. if it did keep working i'd take it for a ride it might keep working but next day DEAD again :mad: WTF. i cleaned the grounds, changed the ignition switch, twisted the pins, re soldered the board, tried tinning the pins, you name it. it always connected to obd reader. you might see if you can find a instrument cluster on ebay ! at least you'll eliminate that part
 
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So started tracing the constant and ignition power on the back of C2 connector. At the connector I get continuity showing for the constant always and get continuity on the ignition power with ignition on. Ignition power wire is orange and tried tracing that but got lost into the large harness connections behind the left dash speaker. The constant power, a gray with white stripe wire, I was able to trace to this small gray connector right by the firewall. Sadly at that connector I am also getting continuity and no voltage. So going to continue tracing. I do have 12 volts at fuse 17 in the PDC. Thinking of just running new power leads from the auxiliary constant and ignition power wires Jeep gives you behind the glovebox. Bad idea?

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