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Looking for the four clock pin functions - 1994 SL500 build date September 1993 (older cluster)

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995 views 5 replies 2 participants last post by  BoatWaco  
#1 ·
I am trying to test a pair of clocks for my 1994 SL500 to see which ones run and set.

I cannot find anything that tells me which of the four connections does what!

I assume they are
  1. power
  2. ground
  3. advance clock forward to set it
  4. advance clock backwards to set it
I'm pretty sure that it runs with power and ground connected and that when voltage is applied to pins 3 or 4 the clock runs fast either forward or backwards.

I actually have two of these cars and the clock runs and can be set in one of them.
The other one unfortunately has the minute hand shaft broken - so no minute hand.

I have two clocks from two slightly different years. They obviously have the same connections on the motor but the small circuit board with the pins to connect to the main board has different style pins.

Here is a picture of both clocks with their small circuit boards removed.
The brown board is from my car. The green is from a donor cluster.
The clock motor mechanisms appear identical except for the color of the insulation on the big coil.

You can see that the connections to the clock mechanism itself are in identical locations - it's just the big pins that are different.
Image


I'd like to know which pin is which!
Thanks.