Hey guys. I’m new to the jeep world. Just bought my first jeep. 1993 YJ. Drove home tonight and when I killed the engine I noticed the dash lights didn’t go off. Checked fuses. None blown but ended up removing the dash illumination fuse to kill the lights. Any ideas where to start looking?
Dashboard illumination doesn't turn off
- Thread starter Late2thashow
- Start date
No. Wasn’t dark when I arrived home. Didn’t use headlights coming home. Just dark enough to notice the dash lights.
Sorry for the confusion.
Sorry for the confusion.
Gauge illumination begins at the Park/Tail 20 amp fuse which goes directly to the Headlight/Parking Light switch panel. The gauge power comes directly from the Parking Light Position Switch (split switch for parking lights also supplies power to the gauge lights). On my 1990 YJ, the ONLY DC power source for gauge illumination is through the Parking Light Switch. With the Parking Light Switch ON, the power is wired directly to the Illumination Rheostat switch (wheel). Here's where it gets a little touchy. This Rheostat controls two functions, 1.) the brightness of the gauge lights through a variable resistor, and 2) provides a path to ground for the interior (dome) lights, but only when the wheel is rotated to the full bright/ON position. The dome lights always have power at the light bulbs, so the rheostat switch AND/OR the "Door Open" switches in the door jams close to complete a path to ground.
A good test in your situation would be to replace the fuse you pulled, sit in the Jeep with the doors closed and confirm your observation that the gauge lights are ON. Verify that the Headlight/Park switches are OFF. You don't need the ignition switch to be on... leave the key out. If the gauge lights are ON, then change the rheostat setting by rotating the wheel towards low. Observe if the gauge lights do dim with the rheostat, conversely do they brighten as you rotate the wheel up. This will tell you if the gauge lights are being powered through the rheostat, keeping in mind that the rheostat may be bad. Also, with the doors closed, rotate the rheostat to the FULL up and ON position. The interior dome lights should come on.
Your next steps will depend on the test results. It may be that your gauge lights are actually getting power from the "always hot" dome light system via a bad rheostat switch. If that is the case, rotating the rheostat will not affect gauge light brightness. Replace the Rheostat and while you're in there, also change the Headlight/Park Light switch assembly.
If the rheostat DOES change the gauge light brightness, then that confirms the gauge lights are getting their power through that rheostat. This is normal. Your "always on" gauge lights must be getting power from another source, possibly a wiring mod by a previous owner, a harness fault or a bad dome light switch in the rheostat assembly. Some of these are unpredictable, but I'd still recommend starting with a new rheostat.
Convince yourself that the interior (dome) lights work correctly. These get their power from the 20 amp dome/courtesy fuse, which offers another testing opportunity. If your gauge lights are on when the Park Light switch is off, then pull the dome/courtesy fuse and observe if the gauge lights go out. But don't get too involved in this, because it will still LIKELY lead to a Rheostat replacement.
A good test in your situation would be to replace the fuse you pulled, sit in the Jeep with the doors closed and confirm your observation that the gauge lights are ON. Verify that the Headlight/Park switches are OFF. You don't need the ignition switch to be on... leave the key out. If the gauge lights are ON, then change the rheostat setting by rotating the wheel towards low. Observe if the gauge lights do dim with the rheostat, conversely do they brighten as you rotate the wheel up. This will tell you if the gauge lights are being powered through the rheostat, keeping in mind that the rheostat may be bad. Also, with the doors closed, rotate the rheostat to the FULL up and ON position. The interior dome lights should come on.
Your next steps will depend on the test results. It may be that your gauge lights are actually getting power from the "always hot" dome light system via a bad rheostat switch. If that is the case, rotating the rheostat will not affect gauge light brightness. Replace the Rheostat and while you're in there, also change the Headlight/Park Light switch assembly.
If the rheostat DOES change the gauge light brightness, then that confirms the gauge lights are getting their power through that rheostat. This is normal. Your "always on" gauge lights must be getting power from another source, possibly a wiring mod by a previous owner, a harness fault or a bad dome light switch in the rheostat assembly. Some of these are unpredictable, but I'd still recommend starting with a new rheostat.
Convince yourself that the interior (dome) lights work correctly. These get their power from the 20 amp dome/courtesy fuse, which offers another testing opportunity. If your gauge lights are on when the Park Light switch is off, then pull the dome/courtesy fuse and observe if the gauge lights go out. But don't get too involved in this, because it will still LIKELY lead to a Rheostat replacement.
