Ok, so I read all the threads, and made a solid attempt at fixing the clock in my 1977 240D. Once I had it apart, it was obvious that the capacitors were toast (at least I think so) because they were all corroded.... so corroded in fact that I couldn't read the polarity markings on them. On the circuit board there were (-) marks one for each pole of the two capacitors. I replaced them with new caps from radioshack.... the ones that everyone uses, using these marks as a guide. NO LUCK. Is it possible that I have them in backwards? I've always heard that they will explode if put in backwards... but all of the other clock components seem to be in perfect shape, I checked the continuity between all the parts I replaced, and it is getting power. Any suggestions would be greatly appreciated.

Cheers!

99% of the time is the capacitors. There are two and you should replace both. Good possibility that both or one is in reverse polarity. Try to trace from the 12 v pin at the back to the capacitors polarity with a ohm meter. The + should be connected there.

my 83 SD clock is not working, I pulled it out (I've been working on the odo gears, so out wasn't much problem) the caps looked fine, no swelling or leaking, but the TACH capacitor looked like a 10 year old AA battery left in a radio!!! really looked terrible.
I know a 240 has no tach, but do you think a hosed tach cap could affect the clock in mine?

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