Only half of instrument panel lights work after LED install

Corbinlane

Corbinlane

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Joined
Mar 7, 2020
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45
Location
Houston, Texas
In my 2000 wrangler SE the lights for the speedometer and RPMS was out so I decided to make the change to LED’s. I pulled the instrument panel out and made the change. I made sure the LED’s are in correctly and working by lighting them up with a battery. Now put the panel back I’m fired up the Jeep and still no lights. I rotated the bulb housing 2x now and nothing. For giggles I checked the old bulbs and they all light up so not blown. I checked all my fuses and none are blown.

Lights that work on the panel
Blinker
Brake
Part time
Airbag
Check engine
Shift

Seems like my main bulbs are the ones not working. I’m going to look tomorrow for any grounding issues but wanted to see if anyone has any other ideas?

Thanks in advance everyone!
 
Have you checked the dimmer for the dash lights? I have heard that some LEDs do not illuminate when the dimmer is enabled.
There is a fuse #3 (behind the glove box) for the lights in the cluster; not sure if the fuse is for all the lights or only to power the cluster and main lights.
I think I would remove the instrument cluster and test to make sure the LEDs that are not working when installed still work when they are removed from the instrument cluster socket.
If they still work I would check the harness connector and the pins on the back of the cluster while the cluster is removed.
 
I have checked the bulbs outside of the cluster and they are all good. I’m not sure about the dimmer, since the lights didn’t work when I got the Jeep not sure where a dimmer might be (any advice)? Is that just turning the knob for the headlight all the way just before it turns the dome lights on?
How should I check the harness connector and pins behind the instrument panel?
 
I'm going to tag @Jamison C for you ..he's awesome on TJ electrical , good dude.

Keep us posted , when you learn , we learn .
 
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Yes.... the knob you are describing is the dimmer.
Since the old bulbs test good, the LEDs test good and the all the fuses test good; then it's either the incoming voltage or a problem with the cluster circuitry.
I was able to locate the Factory Service Manuals for a 2003 TJ. I looked thru the Body Diagnostic manual with schematics and pinouts. The MFS C1 on page 180 has 20 pins and pin 8 is for the Panel Lamps Dimmer Signal. Looking at the connector with the connector release up the pins go right (1) to left (10) on the top row and 11-20 on the bottom row.
It may be difficult to measure the pin 8 on the back of the MFS for voltage.
 
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TJ4Jim said:
Whatever bulbs do not light up then remove the bulb and rotate 180 deg, polarity can be an issue.
Click to expand...

The OP said that the original bulbs would not illuminate when he purchased the Jeep and after installing the LEDs they still would not illuminate so he rotated the bulb holders twice to ensure they were installed properly. I am thinking the MFS or the arm with the dimmer switch may be the problem.
 
Rotate the bulb in the housing and also rotate the housing in the cluster. There will be one correct combination. Do it at night so it's easier to tell what's on and what's off. Or throw a blanket over your head to check when you're in the driver seat.
 
Do
Corbinlane said:
In my 2000 wrangler SE the lights for the speedometer and RPMS was out so I decided to make the change to LED’s. I pulled the instrument panel out and made the change. I made sure the LED’s are in correctly and working by lighting them up with a battery. Now put the panel back I’m fired up the Jeep and still no lights. I rotated the bulb housing 2x now and nothing. For giggles I checked the old bulbs and they all light up so not blown. I checked all my fuses and none are blown.

Lights that work on the panel
Blinker
Brake
Part time
Airbag
Check engine
Shift

Seems like my main bulbs are the ones not working. I’m going to look tomorrow for any grounding issues but wanted to see if anyone has any other ideas?

Thanks in advance everyone!
Do any of the LEDs light? Did you try reversing them?
Click to expand...
 
CharlesHS said:
Yes.... the knob you are describing is the dimmer.
Since the old bulbs test good, the LEDs test good and the all the fuses test good; then it's either the incoming voltage or a problem with the cluster circuitry.
I was able to locate the Factory Service Manuals for a 2003 TJ. I looked thru the Body Diagnostic manual with schematics and pinouts. The MFS C1 on page 180 has 20 pins and pin 8 is for the Panel Lamps Dimmer Signal. Looking at the connector with the connector release up the pins go right (1) to left (10) on the top row and 11-20 on the bottom row.
It may be difficult to measure the pin 8 on the back of the MFS for voltage.
Click to expand...

Can I ask you to dummy down your comments about the body diagnostics? I don't really follow you.
 
Multi Function Switch - MFS

1584626051494.png
 
MFS.... Multi Function Switch which is inside the clam shells on top of the steering column. This unit controls the low and high headlights, turn signals, emergency flashers, dimmer, windshield wipers, windshield washer, on some Jeeps it controls the fog lights.
If you were to remove 2 sometimes 3 screws from the bottom the clam shells that cover the steering column will come apart and the MFS will be screwed to the top of the column. There are two electrical harnesses, the larger is the one that I am referring to . You would need to disconnect the harness to test for voltage on the terminals of the MFS.

This is the type I was talking about..

169991.jpg
 
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Thanks @AndyG. Low voltage wouldn’t affect two separate spots. It would just dim every bulb altogether. The power, signal runs through a circuit board to each light, think a string of Christmas lights.

If it were me, I’d pull the bulb sockets out and clean the contacts really good. There’s two tiny metal tabs on each socket that make contact with the circuit board when twisted into place. Make sure those are clean and bent outward enough to make that contact. Also make sure the mounting surface on the board is clean too. It’s possible it got wet at some point from the top being off and there’s some corrosion in there.
 
New update, I also realized the 3 lights behind the thermostat control panel deal is not working either when I pull the knob out to turn the headlights on. I figure this could be a new deal. I don’t believe it’s the cluster or bulbs problem now. I’m thinking whatever it is that turns the lights on when the headlights are on is what’s causing the problem.

Things I’ve tried
1. Bulbs work in their housing. I checked each one with a battery to make sure it lit up.
2.Rotated each bulb housing in the cluster 2 times.
3. Checked all fuses

Also I looked today for the ground. Can anyone confirm the picture below is the correct spot? If so this connected well. If it’s not the correct spot can someone direct me to the right spot? Possibly with a picture?

06CF4C21-7FD2-40D9-A14D-7503E22643D8.jpeg
 
Another thing I just thought of, the dome light and floorboard lights don’t come on from an open door. They only come on when you turn the dimmer knob till it clicks. The button the door pushes does not have a cap on it. They are able to pop out and get pressed in. Maybe the plug goes there? Maybe that has something to do with the other lights?
 
Do you have any aftermarket powered accessory in that vehicle particularly tapped to the fuse box or any circuit?

If you do remove that before you try anything else.

I had no rear defroster and it turned out that I had my backup camera tied to the cluster circuit and that was confusing everything.

You can cross one wire on a TJ and flash your lights and it will change the channels on your television.
 
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