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 #394638  by MoPar~Guy
 
I noticed on my drive home today, in the dark, that the backlighting of the 4 gauges (fuel, speedo, tach and temp) was not working. All other interior, dash, overhead and instrument panel lights / indicators were working as normal and responding to dimmer control.

The gauges themselves were working fine.

My PDF service manual shows the gauge backlights as (I believe) incandescent type 194. I can't locate them on the wiring diagram though.

Are they wired in series or parallel? As in, if one goes out, they all go out? If not, what could account for them all going out at the same time? Are they fed power through their own fuse?
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 #394639  by KxWarrior
 
If youre driving a 300M, they have a module that powers the instrument panel via Electroluminescence i.e. EL strips. If that module fails, it will cause that issue.

You'd need a new module, or wire in your own, for it to work with that cluster. (Or a new cluster entirely) .

Intrepids (aside from Popo), and LHS/Concorde had bulbs in them.
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 #394640  by MoPar~Guy
 
It looks to me like these are individual back-lights that can be removed:

LH-cluster-lights.gif
This is an '04 300m I'm talking about.
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 #394641  by FIREM
 
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 #394642  by MoPar~Guy
 
I've never taken an instrument cluster out of an M before. But I have added backlight LED's to the headlight switch (of this same '04 M) because they were de-content-ed for MY 2004 (and maybe earlier). And I did wire these LED's to the backlight power wire going to the clock (it seemed the easiest place to access that line).

The diagram I posted above is from a '2000 300m/Intrepid/LHS/Concord service manual, and the way I read that diagram and surrounding text, it sure looks to me that the backlights are just plain 194 lamps.

So did the '00 M's have plain regular backlight lamps, but later they changed it to something unnecessarily electronically fancy?
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 #394644  by KxWarrior
 
From what I'm aware of, from 1999 on, the 300M had the EL strips in the cluster. I can't speak from experience as I own an Intrepid, but every cluster ive pulled apart from a 300m has had those EL strips
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 #394645  by LUNAT1C
 
Every 300M ever made has had EL gauges. It's a throwback to the 1963 letter cars.
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