Weird issue with dash lights and dome lights

[Ed Hickey]

2001 TJ, 4.0 5-speed. Today. headlights on, all ok. Then for no apparent reason the dash lights com on bright and the dome and courtesy lights come on. This last about 1 second then it goes back to normal. Trouble repeats. Then the ignition lights all come on as if you were going to start the car, and the engine stays running. Then goes back to normal. I park in my driveway, shut the engine off and turn out the lights. The tach and speedo sweep from the center all the way to the right and then back again. This repeats about 5 times and then the dash warning lights flash about 5 times. It keeps doing this until I disconnected the battery. Anybody have any ideas?

 

[Chris]

Sure sounds like a bad connection or a bad ground somewhere.

 

[AndyG]

Check every ground. Calling @Jamison C ....he's excellent with electrical as well. The @ signal will notify him.

 

[CharlesHS]

Check the ignition switch and terminals for signs of overheating.
Check the ECM (3) 32 pin and harness connectors for oxidation; then ensure the harness connectors are snapped into the ECM receptacles.

 

[Artsifrtsi]

The tach and speedo sweep from the center all the way to the right and then back again. This repeats about 5 times and then the dash warning lights flash about 5 times. It keeps doing this until I disconnected the battery. Anybody have any ideas?

My '05 did this when the battery died.

I'd check grounds as @Chris mentioned, then have battery tested, then check alternator.

 

[KevinC74]

Check the switch on the door frame. My dad's had cracked and was causing a short with the door closed. Made the door chime go off randomly, interior dome flick off and on, seatbelt warning chime, and similar dash issues to what you describe.

 

[Jamison C]

Thanks for the tag @AndyG I’ve been away in Colorado. @CharlesHS is also super good with TJ electrical maybe he’ll chime in.

*edit* looks like he already has!

 

[Ed Hickey]

2001 TJ, 4.0 5-speed. Today. headlights on, all ok. Then for no apparent reason the dash lights com on bright and the dome and courtesy lights come on. This last about 1 second then it goes back to normal. Trouble repeats. Then the ignition lights all come on as if you were going to start the car, and the engine stays running. Then goes back to normal. I park in my driveway, shut the engine off and turn out the lights. The tach and speedo sweep from the center all the way to the right and then back again. This repeats about 5 times and then the dash warning lights flash about 5 times. It keeps doing this until I disconnected the battery. Anybody have any ideas?

UPDATE: I haven't had a chance to work on this, and at the rate I'm going it won't be for awhile. However, I reconnected the battery and the problem is still there. I said the magic words WTF and smacked the dash right above the radio, and most of the problems went away. Now the smaller gauges, gas, oil etc. slowly vibrate on their left side pegs. I tapped on the cluster with the tip of one finger (no magic words or fist) and it stopped it. Do you think the cluster could be bad?

 

[Zorba]

Microphonics. A bad connection somewhere - possibly inside the cluster like a cracked circuit trace. Or elsewhere - plug/unplug all nearby connectors, wiggle things, etc. You *may* find it that way...

 

[CharlesHS]

UPDATE: I haven't had a chance to work on this, and at the rate I'm going it won't be for awhile. However, I reconnected the battery and the problem is still there. I said the magic words WTF and smacked the dash right above the radio, and most of the problems went away. Now the smaller gauges, gas, oil etc. slowly vibrate on their left side pegs. I tapped on the cluster with the tip of one finger (no magic words or fist) and it stopped it. Do you think the cluster could be bad?

There was a TSB generated by Chrysler Jeep around 2000 that addressed a known problem with the (2) BUS connectors that the instrument cluster plugs into. The metal clips inside the bus connectors and the pins for the cluster will develop microscopic black oxidation that interrupts the signal to and from the instrument cluster.
I had this problem on my '98 XJ about 6 months after purchasing the Jeep new in '97. Reinserting the cluster into the BUS connector, cleaning the pins with contact cleaner, scuffing with scotch bright and even had the TSB repair (cut and splice in new BUS connectors) performed by the dealership which had short term results. Nothing that I did ever became a permanent fix since the microscopic black oxidation would always return. Periodic cleaning with plastic safe contact cleaner (can be purchased at Walmart) had the longest results.
Not saying your problem is solely from this problem, but it's something to check.
Also check the grounds that are behind the drivers/passenger side lower dash speaker grills and the grounds that are beneath the lower dash in the kick panels on the drivers/passengers sides.

 

[glowell222]

@CharlesHS I had this same issue, though there wasn't a TSB on it back in '99 when I took it back to the stealership for a fix. The manifestation in my machine-the entire cluster would die, come back on, repeat a few times, and then the speedo wouldn't work. The service receipt didn't include any details at all other than "reseated cluster after cleaning and coating the connection points. Could not recreate the issue after this service". Problem went away.