crazy cluster problem
 

1981 280se greymarket. W126. Last night I turned on the headlights and everything was fine. Fliped on the brights and the oil went down one bar, temp pegged to max. Turn on the turn sig and guages pulsate. Adjust cluster lights and guages same as with bright lights. Fuses good, could it be a relay? Any suggestions.
Thanks in advance. Frank

I had a similar problem with my SL
 

Not exactly, but similar. See my post under the SL forum. It turned-out there was an intermittent grounding issue behind the instrument cluster.