Use a charger to test as you go. It won't melt wire as fast if there is an issue. Take care and take your time it will work.
I have to disagree with this one. Make some long leads for your multimeter and use it to test circuits. Check both ends for continuity. Then check one end to ground for open. If it is shorted to ground and you use a charger, battery or any other hot lead you have ruined the wire and will need to piggy back another one in. If you find the short with a meter, no harm is done. Find the short (possibly a wrong connection) and fix it.
