Malcom,
It could be a mis-match between the resistance range the sending unit
provides, and the range the meter needs. I ran into this with a fuel gauge
that came with my TR3. Even worse, that gauge required the resistance to
vary in the opposite direction! Here's how you can tell.
1) Measure the resistance across the connections of the sending unit when
the float is positioned at full and empty
2) By a few cheep resisters (50, 100, 200 ohm) at a radio shack. Attach
those in line with power going to the fuel gauge. This should let you know
what it wants at empty, 1/2, full. You can attach multiple resisters in
series to add the resistance (100 + 50 = 150). You can attach two in
parallel to "halve" the resistance (100 + 100 in parallel = 50 ohms). This
is useful if you can't easily find a nice mix of resistors at the store.
It was by doing the above that I found that the gauge was just flat out
wrong for my car. Hopefully, you'll find a more easily remedied problem than
that was.
Good luck!
Dave Moag
62 TR3B
77 Spitfire
La Canada, CA
-----Original Message-----
From: owner-triumphs@autox.team.net
[mailto:owner-triumphs@autox.team.net]On Behalf Of Malcolm Walker
Sent: Saturday, May 27, 2000 11:37 AM
To: triumphs@autox.team.net
Subject: Gas Gauge Oddities
I'm trying to get my fuel gauge to work properly. Before, it would
always read 1/4 tank if the level was > 1/2 in the tank, and read
properly below that (although sometimes it would read 3/8)
I've got a new(er) tank sending unit from a TR6. Now, (just by putting
the sender into the circuit and holding the float at its limits) I get
correct readings for Empty but Full puts the needle pointer at just
below half.
Any suggestions? When I pull the sender out of the circuit and short
the leads (~0 resistance), it reads just under 3/4 tank. So either
something's too resistive or something's not getting enough power.
Where do I start?
Thanks in advance...
-Malcolm
----
To know that which you do not know, is the best.
--Confucious
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