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Grounding
- Thread starter RonR
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TR3driver
Great Pumpkin - R.I.P
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That can make it hard to tell, especially since just hooking the battery up the other way will usually work (more or less). So my suggestion, if there aren't any electronics (alternator, radio, etc.) is to just connect it the way you want it to be; then deal with any issues that arise.
However, there are some clues you can look at:
How is the coil wired? If it is marked CB/SW, then CB would go to the distributor for positive ground, to the wiring harness (ignition switch) for negative ground. If it is marked +/-, then + would go to the distributor for positive ground, - for negative ground.
Look carefully at the openings in the battery cables. The positive post is slightly larger than the negative.
What, if any, electronics are installed? Generally there are only a few items that will even work with positive ground, and they usually need to be wired differently or have a switch to be set.
Last clue would be to hook up a battery and see which way the ammeter indicates. If it swings to "+" with (for example) the headlights on and the engine stopped, then the battery is connected backwards to the way the ammeter is wired.
Perhaps too obvious, but your TR3 would have originally been positive ground. Lots of folks (myself included) opt to convert to negative, though, for ease of adding electronic components.
However, there are some clues you can look at:
How is the coil wired? If it is marked CB/SW, then CB would go to the distributor for positive ground, to the wiring harness (ignition switch) for negative ground. If it is marked +/-, then + would go to the distributor for positive ground, - for negative ground.
Look carefully at the openings in the battery cables. The positive post is slightly larger than the negative.
What, if any, electronics are installed? Generally there are only a few items that will even work with positive ground, and they usually need to be wired differently or have a switch to be set.
Last clue would be to hook up a battery and see which way the ammeter indicates. If it swings to "+" with (for example) the headlights on and the engine stopped, then the battery is connected backwards to the way the ammeter is wired.
Perhaps too obvious, but your TR3 would have originally been positive ground. Lots of folks (myself included) opt to convert to negative, though, for ease of adding electronic components.