Dash Illumination '92 240DL

Just bought this car last week and now I find that the dash has no lights at
night. The dash rheostat was missing when I purchased the car so off to the
wrecking yard I went and procured one. Installed it and turned on lights to
a nice display of smoke and smell with the rheostat glowing a nice cherry
red.Now I know why it was missing.
So next I bring out the Bentley manual and try to read the hieroglyphics
they call schematics.Find that the output of the rheostat goes to at three
different places in the dash. One being to the radio, which happens to be an
aftermarket Kenwood unit. So I pull out radio and look at wiring. Find that
one wire from rheostat has a short to ground. Could not find out exactly
where,since wire disappears into large wiring bundle behind dash.So I then
thought well I'll just use the other wire that does not have a ground on it
and maybe get back at least some lights. No good, lights still do not
work.But the rheostat does not get hot and smoke anymore, just no lights
still.
Anyone have any ideas what to look for now.
Thanks Larry

 

Is the rheostat any good still? I shorted the one in my car once and it
burned out almost instantly. If there's no shorts and nothing lights up, are
the bulbs good? Do you have a volt meter?

 

Hey James

Yes the rheostat is still good. I ohmed it out and it shows it has a max
reading of about 22 Ohms.Also checked the bulbs, they are good.
I wish I had access to another 240 to check what the reading is on the
brown wires from the rheostat to ground. With the wires disconnected from
the rheostat. Anyone's help would be appreciated.
Larry