Richard Seaton wrote:
"If this can be done will going to a higher amp hurt my
Amp meter (not volt meter). What are the limits of the stock amp meter if
increasing the output of the alternator."
and Rick O replied:
"I'm running a 60-amp Bosch alternator with no problems whatsoever."
There are two aspects of this question to consider: how much current the
alternator CAN supply, and how much it WILL supply. How much it WILL supply is
determined by the car's electrical system. Upgrading to a more powerful
alternator will not cause the car to draw more current from the alternator than
before (assuming the alternator could supply the full load, which they usually
could if the engine was above 2000 rpm or so).
If every electrical load in a TR6 were to be on at the same time (which they
never will), the current draw would be, excluding a radio, under 45 amps.
The maximum electrical load that is likely to be on at any given time is about
20 amps. At idle, the alternators in earlier TR6s will not provide 20 amps.
Upgrading to a 50-60 amp alternator will provide the 20 amps at idle easily,
but it will not provide more amps than are needed. Another way of looking at
it is: the alternator doesn't "push" amps, the electrical system "pulls"
amps from the alternator. The alternator will not provide more amps than the
electrical loads pull from it.
There is, however, one case where the alternator might be called upon to
provide more current than the 30 amp rating of the ammeter. If you should allow
your battery to become severely discharged, jump start your car, and then let
the alternator recharge it while you drive the car, a more powerful
alternator might be called upon by the charging of the battery to provide more
than 30
amps. As long as you avoid this situation, you should have no problem with
the extra alternator capacity.
This didn't answer your question though. I too would like to know what the
maximum current capacity of the 30 amp ammeter is. I just happen to have a
disassembled TR6 ammeter in my hand. There is nothing between the two input
terminals but a short piece of wire, formed into a loop, looking to be about 10
gauge, but maybe only 12 gauge. The needle movement is only magnetically
connected to the wire loop. I am of the opinion that short periods of 60 amps
would not hurt the wire between the terminals, nor do I believe the needle
would
be harmed by being driven hard against the limit stops unless the 60 amps were
applied suddenly, causing the needle to bang against them. This is only an
opinion, though, and I do not know for sure if this is true or not. I would
really like to know.
With the one exception mentioned above, I'm in agreement with Rick - go
ahead and do it and don't worry.
Dan Masters
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