A fuse?

[JamesL]

All my dash lights have gone - I have an interior light but nothing for the dials/clock

A fuse?

If so can someone please point me in the direction of which fuse in the fuse box? Thanks


edit
Sorry, just did a search, realising there's very little about these cars that hasn't been discussed on here. I'll have a fiddle with my resistor/rheostat and check the end fuse connection

[jeffc280sl]

Tosh,

Illumination of the dash lamps is controlled by the regulating resistor on the center gauge.  Power comes from fuse 7 and then passes through the center gauge resistor.  Here is a pic of what it looks like on the inside.  Basically the resistor is a spring that has a rotating contact controlled by the adjustment knob.  As you rotate the knob the contact moves along the spring so that it is either closer or father from the power source.  The closer the brighter the lamps.  If the spring is broken the resistor has failed and your lamps will not have any power.  There should be a full position for the resistor which bypasses the spring an supplies full power to the lamps.  Try moving the knob to the extreme right and left (clockwise/counterclockwise) to see if you can get the lamps to come on.  If you can I'd say the spring is broken of the contact that rides on it is dirty.  It's not a big job to fix after you remove the center cluster.  Removing it is a bear as you know.

Download Attachment: dimmer.jpg
52.49 KB

Jeff C.
1970 280SL 4-speed

[JamesL]

Oh dear,

twiddled my knob and other than shredded fingers (I doubt anyone's twiddled with it for many years), no dice on the lights

[jeffc280sl]

Tosh,

Fuse #7 also feeds the right side parking lamps.  Do these work?  This feed does not pass through the dimmer control.  

If they work it would have to be the dimmer or a loose ground behind the gauges.  Sounds like the dimmer control was very hard to turn which indicates dirt or corrosion of some sort.  I'm afraid this means the gauges may need to come out. Cleaning the dimmer is pretty easy.  Restoring the dimmer function spring is more difficult.  At a minimum you can restore the lamps to full brightness.

If they don't work look try to spin the fuse to make better contact with ends.  See if that helps.

Jeff C.
1970 280SL 4-speed

[rwmastel]

Tosh,

There are posts in the forums about by passing this dimmer device.  That might be a good option, as even at full brightness they are not very bright compared to modern standards.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420