The braided ground cables can fail, but it's unlikely. The most common point of voltage loss or high resistance will be where the braid attaches to the lug terminal on the ends.
Here's the most effective way to find a bad connection- - - -turn the multimeter DC voltage scale to the lowest possible setting and touch one probe to one side of a connection, and the other one to the terminal or conductor right beside it. For instance: place one probe to the + battery post, and the other one to the terminal clamp on that same post. Have someone push the start pedal. ANY reading on the meter indicates how much voltage is being consumed to push the current through that specific connection. On a 6V system, the resistance of any particular connection should be less than 2/10 volt. Now, check the voltage loss from one end of the cable to the other- - - -one probe at the battery, the other at the end of the hot cable attached to the starter. NO voltage drop is acceptable in the cables, hot or ground. Check every connection and conductor from the battery, to the starter, and all the grounding points back to the starter negative post the same way- - - -each time attempting to crank the engine while you're checking a connection. When you find a big voltage drop across a connection or a conductor, you've isolated the source of the open circuit. I started doing those types of tests in the early 1960's, and spent over 30 years teaching automotive electrical diagnosis.
These are not idle pipe dreams- - - -I made a good living finding electrical gremlins after others had given up on the problems. Good luck!
Jerry
Last edited by Hotrod Lincoln; 04/15/2014 7:00 PM.
