Mechanics

INSTRUMENT CLUSTER LIGHTS NOT WORKING

1994 Plymouth Sundance • 138,000 miles

Pretty simple problem. All gauges work but the lights don't in my instrument cluster. I checked the bulbs in the back and they all look good. The only other thing is the lights for the heater/ac controls don't work either. All other interior lights work as well as exterior, dome, trunk etc. Just those two areas. All fuses are good. Looking at the wires/connections they all look okay too. I haven't dug all the way to the firewall just wondering if there's something I may be missing that is simple and hasn't been checked.


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Norcal
October 8, 2012.



Have you checked for voltage getting to the cluster?


Caradiodoc
Oct 8, 2012.
UPDATE: Found 1 bad bulb. Is this like a set of old XMAS tree lights in regards to one bulb goes out they all do?


Tiny
Norcal
Oct 8, 2012.
Well I figured, since the gauges work there's power getting there. Otherwise I have no clue which pin should be getting the juice


Tiny
Norcal
Oct 8, 2012.
Things like my check engine lights and brake, seatbelt lights work. Just the lights to the gauges don't


Tiny
Norcal
Oct 8, 2012.
You're making this WAY too complicated. Check for voltage on the orange wire in the black round connector. That should be the fourth terminal from the keyway.


Caradiodoc
Oct 8, 2012.
Lol ok. I'll check.


Tiny
Norcal
Oct 8, 2012.
Do you have the original radio or an aftermarket replacement? If it's the original one, you should notice the display doesn't adjust with the headlight switch rheostat, and there's no back-lighting in the faceplate either. Suspect the head light switch.

If you have an aftermarket radio that was recently installed, they likely used the lighting wire for a ground wire. In that case the 5 amp fuse will be blown.


Caradiodoc
Oct 8, 2012.
No power to orange wire. Just occurred to me it may be a dimmer problem since the heater/ac lights don't work either. Is this the next place to check?


Tiny
Norcal
Oct 8, 2012.
It had no radio however there was evidence of a aftermarket stereo w/amp. I just installed a new stereo the other day however the problem was there before I did that. I used a ground strip (thin, wide metal mesh type line) they had in there for ground.


Tiny
Norcal
Oct 8, 2012.
Previous owner might have blown the fuse for the lights. There is no ground wire in the original two radio plugs. You have to use that braided ground strap or black clip-on wire for the ground. There is a tail light wire to the radio to tell the display to dim when you turn on the lights, and there's a dash light wire to the radio to tell the display how much to dim. Because of the large number of bulbs on each circuit, both wires will read very low resistance to ground, and that's why people often mistake them for ground wires.

First check the 4 amp fuse, # 5, (not a 5 amp fuse like I mentioned earlier). If it's okay, check for voltage on both terminals when the head light switch is on. If there's no voltage there, go back to the head light switch and measure there.

The head light switch isn't too hard to remove to test voltages. Measure on the 18 gauge tan wire with the switch turned on. It's the one sitting kitty wumpus in the corner. If there's nothing there, check on the 18 gauge black / yellow right next to it, (half way between the front and back of the connector.

Also look at those two terminals in the connector to see if they're blackened from being overheated. By this time you should have found the problem because that last voltage is tied to the tail lights which I assume are working.


Caradiodoc
Oct 8, 2012.