Matt,
A hot wire (or rms averaging) voltmeter measures the heating effect of
the voltage and reads out the average. The voltage stabilizer isn't solid
state, but a thermal switch. The switch opens and closes periodically to
give and 'average' voltage of about 10vdc equivalent. The fuel and
temperature gauges both operate on the average (they are thermally operated
to) voltage and aren't concerned with the switching on and off ( notice how
slow they increase or decrease readings). If your stabilizer is pulsing on
and off ( somewhere around once per second) then it's probably ok. I'd look
a cleaning all the connections from the stabilizer to the gauges and from
the gauges to the sensors. It sounds like you've got some corrosion started
somewhere along the way. Corrosion at the fuel sender ground point is
common. It's the old corrosion increases resistance, which decreases
current flow through the gauge, which reduces power, which reduces heat,
which causes the gauge to read low trick.
Harlan.
-----Original Message-----
From: Kulka, Matt <Matt.Kulka@hboc.com>
To: MG List <mgs@autox.team.net>
Date: Monday, December 21, 1998 10:32 AM
Subject: RE: Many Thanks! -- Dumb Present Owner Buys Gas
>-----Original Message-----
>"...Never trust the gauge. Use it for estimates only..."
>
>Agreed. Which brings up a question.
>
>Currently, my fuel and temperature gauge are both reading low. I
understand
>this is due to the voltage stabilizer. I found the thing. It looks small
>enough (and un-original enough) to be a solid state unit. I put my analog
>voltmeter on it and got the 12v/0v/12v/0v rhythm.
>
>Is there any way to test one of these things with a digital or analog
>voltmeter? My Haynes refers to a "hot-wire" voltmeter, but I don't know
>what that is, and neither of my mine seem to qualify.
>
>Beyond that, is there any way to adjust it, or is it just plain disposable?
>
>Thanks. Again.
>
>Matt Kulka
>'74 B - which can get 60 miles on an 'empty' tank, and never overheats.
>
>
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