try sanding the contacts of the bulbs.. .are you using H4 bulbs? or is it the US Spec sealed beam type?.. if so.. just sand the contacts to remove teh grime that could cause the improper contact of electricals.

just my 0.2 cents.

__________________
Mike

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1975 200 - Sold (no pix);
1978 200 - Sold - http://www.pbase.com/hboy/redbaron
1979 300TD - Sold
http://www.pbase.com/hboy/greenwagon
http://www.geocities.com/hboy726/300TD.html
1985 230E - now my daily driver...