Posted by David Sherman on Thursday, April 15, 2004 at 9:44PM :
In Reply to: Hooking up battery backwards? posted by Dave on Thursday, April 15, 2004 at 7:50PM :
On an old vehicle with a regular generator (not alternator) and no electronic devices, it doesn't really matter which way the battery is hooked up, so long as you polarize the generator appropriately before starting the engine. That just means to briefly (a second or so) connect the non-grounded battery terminal to the field ("F") terminal of the generator or regulator. You can use a piece of wire of sometimes a screwdriver if the terminals are nearby. Even if you don't polarize it, it might start up with the right polarity. The problem is that if it starts up wrong, it could burn up the generator or regulator trying to charge the battery backwards, and it won't do the battery much good either. But other than that, nothing cares, not even the starter motor. Old-fashioned gages, lights, horn, flasher, mechanical voltage regulator, etc all work fine. If the ammeter needle goes the wrong way, just swap the wires on the back of it. I hook everything I get up for negative ground, regardless of what it was originally, mainly to avoid problems when jump-starting and to avoid confusion other times. As far as I know, no alternators have been made for positive ground.
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