Wiring a Bosch ignition switch

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sequena1

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I recently bought a Bosch ignition switch from Westfield for my OM 636. It has no wiring diagram and no, the nice man at Westfield can't help. Could anybody help with the interpretation of the numbers on the lugs. I think 30 is the main battery feed and 15 is the ignition/ auxilliary link. What are 17, 19 and the smaller lug labelled 50a or maybe 691 (both numbers are adjacent to this connection). Many thanks in advance for any assistance
 
Ha ha! - I had the identical problem a couple of weeks ago. Many hours on the web found me a pic from a German Bosch site with the labelling for the contacts.

The pic isn't handy right now, but the numbers refer to DIN standard terminal designations (Google it /forums/images/graemlins/smile.gif )

15 = switched +ve (output from ignition switch) [For aux circuit supply]
17 = Start
19 = pre-heat
30 = Input from batt +ve, direct [via common stud on starter motor]
50 = starter control, direct [starter motor solenoid]
50a= output for starter control (series-parallel batt switch)
58 = stop solenoid, if you have it

If you had the old series glowplugs, then there was a glowplug controller (a glowing resistor covered by a small grill on the dash) between 17 and 19. AFAIK with parallel plugs then these 2 terminals can be bridged directly together, with the glowplug supply directly from 19.

It is a nice bit of kit - it took me a while to realise that the second indent to the right is for preheat, then push in and click to the right for start. For a long time I had been pushing in and turning slightly to preheat, and not always getting it right /forums/images/graemlins/smile.gif
 
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