Date registered: Oct 2005
Vehicle: '72 250/8, '76 200d
Location: '79 300sd, 79280se
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
RE: 250 114 coil wiring needed ASAP
The message from chrismalm rings a bell for me. My '72 250 has an electronic module under the battery tray(why such a hidden, potentially corrosive spot?). The coil negative does go direct to ground. I believe (its hard to see under there) that the module is also grounded, but I don't know for sure. THIS IGNIION IS DIFFERENT(MORE COMPLEX) THAN MOST OLD POINT TYPE SYSTEMS) The wire from the points that would go to the coil negative on most older points-type ignitions goes to this module.
I learned all this the hard way when my car wouldn't run, before I discovered the existence of the module. I cleaned the contacts on the module and the grounds mentioned, and she was goin' again. There are more than two wires to the module as I remember, but can offer no more detail at this point.
For general knowledge about contact point ignitions: The Haynes volvo 140 manual 1966-1974 page 93(mine is Haynes Publishing #ISBN 0 85696 129 9) has a eloquent but plain description the theory behind, and function of, breaker point ignitions-very thoughtful and quite Brittish. I wouldn't be supprised if Haynes used this same text in other old manuals.