Hi Everyone,
A couple of weeks ago I asked about my voltmeter not reading right, just
thought I would pass on more info about what I discovered.
I discovered one night that my voltmeter in addition to reading
incorrectly (about 2 volts low) it was also hotter to the touch than the
other 2 gauges. So I decided to buy a new one from www.gaugeguys.com.
(Someone asked about an electric oil pressure gauge sometime back -
gaugeguys have one in the cobra section of the site.
When I got the new one I checked it out, it was reading what I expected
and verified with my VOM. Unfortunately, it didn't match the other
gauges as well as my old one. When I took the rim off the old one to
paint it to match the other gauges, I noticed that the face plate that
says volts popped off quite easily. I proceeded to try to pop off the
face plate off the new one. WRONG! It was pressed in tighter than I
expected and pulled the whole gauge apart.
I played around with it and got the needle back where it was supposed to
be - now it read incorrectly.
I bent and rebent the spring that provides the tension on the needle
until I got it looking right and reading correctly as verified by my
VOM. It wasn't any fun.
Anyway, I discovered that under 2 plugs on the back of the voltmeter are
slots that can be used to move the insides of the voltmeter and adjust
the readings. The left side adjusts the spring that provides tension
and one of the pivot points for the needle. The right side adjusts what
actually moves the needle ( I think it is a bimetallic leaf that
responds to the heat in the coil of wire wrapped around it). Right and
left are as you look at the back of the gauge. I didn't manage to
figure out what the movement of these would do, so it would be wag
adjustments.
Just wanted to update everyone and thank everyone for their responses again.
Roger Elliott
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