Speedo and tach issue

[DakotaTJ]

I realize this has been discussed but still haven’t been able to fix mine, 1998 speedo and tach randomly quit working, they just drop to zero. Doesn’t seem to have anything to do with hitting bumps, etc. I’ve tried the dielectric grease thing and bending the pins. I can’t imaging drilling new pilot holes for the ground wires would be the fix as all the other gauges work.

What’s everyone’s thoughts about the multi function switch being the issue. Reason I ask is that if I flip the hazard switch twice, quickly, that seems to wake up the tach and speedometer. I’m also 70% use that my hazards come on when the gauges drop out. Also the “airbag” light comes on.

Thanks for any advice.

 

[jjvw]

A not-so-wild guess is to make sure the big wiring harness connection above the engine at the firewall is fully seated. I had a similar issue on mine years ago and that was the problem.

 

[DakotaTJ]

These bad boys? Thanks, I’ll give that a try.

 

[jjvw]

These bad boys? Thanks, I’ll give that a try.

View attachment 638669

Give them a good wiggle and squeeze. In my case, I had disconnected the connectors sometime before the dash cluster started cutting out and I learned I didn't do a good job of connecting them back together.

 

[DakotaTJ]

Give them a good wiggle and squeeze. In my case, I had disconnected the connectors sometime before the dash cluster started cutting out and I learned I didn't do a good job of connecting them back together.

Tried that. Didn’t seem to help. Going to blast them with some contact cleaner.

 

[DakotaTJ]

Well. Shoot. That didn’t work. Cleaned the connections and made damn sure they were seated properly.

 

[hear]

Speedo comes from the sensor at the back of the t-case, but the tach comes from the crank (or possibly the cam) sensor. So for them both to have gone out would suggest a bus or cluster related problem (which is what jjvw has you checking, for the record).

 

[DakotaTJ]

Thanks. The battery is 10 years old. Seems fine, but could that be part of the issue?

 

[jjvw]

Thanks. The battery is 10 years old. Seems fine, but could that be part of the issue?

Related or not, ten years is long past what most get out of a car battery.

 

[CharlesHS]

What’s everyone’s thoughts about the multi function switch being the issue. Reason I ask is that if I flip the hazard switch twice, quickly, that seems to wake up the tach and speedometer. I’m also 70% use that my hazards come on when the gauges drop out. Also the “airbag” light comes on.

Interesting that flipping the hazard switch twice wakes up the Tach and Speedometer.
On my 98 XJ I had a similar problem with the Speedometer and Tach losing communications and the Air Bag light coming on.
I tried cleaning the Instrument Cluster contact pins and BUSS clips with scotchbrite and a Jeep Tech friend tried his fix, but nothing worked more than a couple months.
The dealer performed TSB 08-15-99 for cleaning the oxidized terminals (microscopic black oxidation) for the BUSS connector which included replacing the BUSS connector. This also only resolved my problem for a couple months when the problem returned.
After owning the XJ for 21 years and numerous times of troubleshooting to resolve the Instrument Cluster problem; my solution to restore operation of the gauges was to make a Right turn with the directional lever and the gauges came back to life.

 

[DakotaTJ]

Interesting that flipping the hazard switch twice wakes up the Tach and Speedometer.
On my 98 XJ I had a similar problem with the Speedometer and Tach losing communications and the Air Bag light coming on.
I tried cleaning the Instrument Cluster contact pins and BUSS clips with scotchbrite and a Jeep Tech friend tried his fix, but nothing worked more than a couple months.
The dealer performed TSB 08-15-99 for cleaning the oxidized terminals (microscopic black oxidation) for the BUSS connector which included replacing the BUSS connector. This also only resolved my problem for a couple months when the problem returned.
After owning the XJ for 21 years and numerous times of troubleshooting to resolve the Instrument Cluster problem; my solution to restore operation of the gauges was to make a Right turn with the directional lever and the gauges came back to life.

You’re saying you flipped on the right blinker and the gauges came back? I’m really thinking there may be a fault somewhere in the multifunction switch that is causing the issue. Worth $45 and 30 minutes to try. Will report back. For now, going to use Waze on CarPlay to get GPS speed info.

 

[DakotaTJ]

Picked up one of these for $30 on Amazon. May be what I have to live with for now. Plugs into the OBDII port and still functions when the gauges drop off. So I'm guessing is a gauge cluster or connection issue, not at the BUSS.

 

[hear]

It's a really good thing you didn't post a link to what you bought so people could check it out.


Like seriously, what a relief.

 

[DakotaTJ]

It's a really good thing you didn't post a link to what you bought so people could check it out.


Like seriously, what a relief.

My bad: https://www.amazon.com/dp/B0957S3F3H?tag=wranglerorg-20

 

[DakotaTJ]

Well. Took the gauges out one last time. Realized the female ends of where they plug in are able to move up and down. Secured them with duct tape (I know, I know). And they've been working great since. Fingers crossed that this "fix" will last.

 

[hear]

Im interested to know how laggy that aftermarket gauge is. Can you video it while you're driving, where we can see the jeep tach & the new gauge at the same time?