Posted by Alan Bowes on October 03, 1998 at 07:47:53:
In Reply to: M37 12 volt help posted by Chris Davis on October 02, 1998 at 15:51:56:
Just a few comments:
If it's cranking slowly, here is a very brief list of the usual causes:
- Voltage regulator problem, preventing proper current/voltage charge.
- Starter motor needs servicing or overhaul (there are several possible internal problems).
- Starter motor misalignment causing binding, or a parts mismatch.
- Bad starter cables or connectors (NOTE: If the battery is in the original location, which I assume it is, the battery cables are quite long and you need some pretty hefty cables of comparable gauge to the originals to prevent too much voltage drop.)
I'd suggest driving it down to your friendly alternator shop and have them check the system. Some shops will do this for nothing. They can check the battery under load, too, which is a good indicator of battery condition.
As to the ballast resistor, it should only be part of the circuit after the engine has started. If you have wired your ignition system properly, the ballast resistor is bypassed during cranking, but is in series with the coil when the engine is running. There are different ways of wiring the system to do this. If you run your engine without a ballast resistor, there is a chance of overheating the ignition coil, plus your points won't last as long (if you use points, that is). This will depend on the coil's primary winding impedance, but generally speaking, coils that are advertised as 12V units should be run with an appropriate ballast resistor in a 12V system.
That should give you some general direction. Feel free to ask more questions.
Alan