engine and drivetrain Wierd '74-'76 starting issues - anyone else experience?

[andreas]

First of all THANKS to all of you who have given me a significant list of things to check - as always this board is AWESOME for someone like me who didn't grow up around cars and is trying to learn this stuff alone!

A very excellent previous post on coils (thanks!) mentions that the external ballast resistor on '74 and later cars is replaced by a wire and power to the coil comes through the starter solenoid (if I'm understanding correctly). http://www.bmw2002faq.com/component/option,com_forum/Itemid,57/page,viewtopic/t,269556/highlight,/

Last summer one of the 3 spade connectors broke off of my starter solenoid and the car wouldn't crank - as an experiment (after looking at a wiring diagram and thinking I was disconnecting the starter inhibitor circuit from the transmission) I unplugged one wire and put the broken one in its place and WOW - car started right up - ran fine for months.

It was only when I let the car sit and the temps dropped over winter that it hasn't started. Now I'm confused - is it possible that I had disconnected the coil ballast resistor override circuit and now the car just won't start because of weak juice coming out of the coil (effected now by the resistor) - too cold to check right now so I thought I'd ask if anyone out there has had any similar experience???

As always thanks for the GREAT advice that comes from this board!

Andreas

[ingraham]

and I agree with your assessment of the problem. You need to trace out your ignition wiring and confirm it is intact. One clarification: Your coil gets power from 1) the ignition switch via the resistor wire during running, and 2) from a direct battery feed from the starter during cranking.

[Lee]

From your tumbler, there is one black wire that energizes the starter's solenoid to make it spin. On the other end of that same starter, there is another spade on which a black wire should also be connected. This black wire send 12 volts to the ballast, but bypasses the resistor and goes straight to the coil. It gives more power to the coil for better startings. When you have finished cranking, 12 volts now comes from the running end of the tumbler and thru the resistance.

Hope it helps.