dash light potentiometer
 

My dash lighting is very poor on my 82 300D turbo. All the bulbs are good but the dash light dimmer switch is acting very odd. I spin it and it simply flickers the light. I suspect the potentiometer (rheostat?) is shot. Somehow I get the impression that these cars have pretty dim dash lighting even when the switch is working. If this is true maybe it would be best to simply bypass the potentiometer so that I get maximum dash light intensity whenever the headlights are turned on. I wouldn't mind saving on the cost of a new switch. I would guess it costs at least $50 as it's a dealer only item.

Has anyone done this? Also does anyone think this is a bad idea?

Thanks,
Elliot

erubin,

That is a common event, and bypassing the potentiometer is a common solution. The dash lighting even with the unit bypassed is just acceptable. Go for it. Jim

Thank you again Jim!

I've done three of these now and there are two tricks to getting the maximum lighting (which still is not that impressive)

1. solder the two posts together (bypassing the potentiometer)

2. paint the inside walls where the bulb reflects.....paint them glossy white. After a few years, they yellow.

In one of my cars this helped dramatically but in the other two it wasn't so impressive.

Don

Same theory as Diesel Don's #2, I took some Q-tips (soaked in rubbing alcohol) and cleaned the carbon or whatever that is which gets inside the prism in my dash in both the 83 & the 84. Swapped a couple bulbs, and cleaned all of the bulbs in the cluster with rubbing alcohol. The 83's backlighting wasn't that bad in the first place, so I don't know if it improved much. But the backlighting in the 84 is ~5X better!!! My 84 also has a flickering potentiometer, but I tested the resistance on it and it isn't that bad so I left it in.

I need to bypass my pot. How do you access it? Difficult?

You have to remove the cluster in order to get to it, after that it is very simple as the two bars are looking right at you after it is uninstalled.

I've got the same problem....no dash lighting. How does one get the cluster out? I have the Haynes manual for the 123's. Is the procedure the same for the 126's?

I believe it is the same procedure, next time I think I'm going to build this:http://viewimages.mbz.org/by_chassis...r/hooktool.jpg

And a link about rebuilding the rheostat
http://instrument.articles.mbz.org/dimmer

With that info i'm ready to try fixing the rheostat before bypassing it. Already have the caps to fix the clock.

Thanks