Message text written by "Dan John"
>Just a quickie and probably makes me sound stupid but how do I know if my
car has a positive earth or not? It's a Spitfire 6 with a TR2000 engine.
Any ideas
Dan
<
Check the battery connections. If the Positive terminal is connected to
ground it is a positive earth system.
Q: What if there is no battery in there? How should I connect it?
A: Does it have an alternator? If so it is most likely to be negative
earth. If it has a dynamo then that is a tough question. One way to check
is to check the battery clamps. One post is bigger than the other one.
The clamps will retian the approximate dimension of the post it was on
last.
Or hook it up and turn on the lights. Does the am meter read discharge or
charge. If it reads charge reverse the battery connectiosn.
Is there a radio? Is it a negative earth model?
There are many different clues that will suggest what the polarity should
be. Check as many as you can before proceeding.
If the car has an alternator assuming that it is negative ground is going
to be right 95% of the time (there are models of alternators out there that
can be configured either way. Hook up one of the battery terminals and
then connect the other one through a 12 volt lamp. Make sure all the loads
are off. If the lamp lights up try it again with the battery terminals
reversed. Do not make the final connections until the lamp stays off.
Dave
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