Allen, the 0 to 70 ohms range given at the mgaguru site is for an MG Jaeger
gauge. The Smiths gauge for BJ8s, and I assume also for BN4s, ranges from 0
to 90 ohms plus or minus. You should recalibrate your gauge after modifying
the test rig with the correct resistors.
Steve Byers
HBJ8L/36666
BJ8 Registry
Havelock, NC USA
-----Original Message-----
From: healeys-bounces at autox.team.net [mailto:healeys-bounces at
autox.team.net]
On Behalf Of Alan Bromfield
Sent: Friday, August 05, 2011 10:20 AM
To: Healey Mail List
Subject: [Healeys] Fuel Tank Sender Unit
Team.
The tank sender unit in my BN4 is one of those Taiwanese pattern jobs. It
came with a rubber gasket that isn't fuel proof, so guess what happened when
I brimmed the tank for the first time? Doh! The outside dimension of the
casing was too big for the tank opening and had to be judiciously filed on
the corners to gain relief, and the screw holes aren't on a consistent
spacing and had to be slightly enlarged to allow all six screws into the
tank ring. Apart from those variations the nicely wound rheostat and double
wiper arms look to be well engineered and the variable resistance is smooth
throughout the range.
My real beef however is that the resistance range of the sender is from zero
(empty) to 100 Ohms (Full). That is a real bear as I went to a lot of
trouble to make one of these calibration devices:
http://mgaguru.com/mgtech/electric/fg_06.htm
which assumes a 0 to 70 Ohm operating range, and then set up my gauge to be
accurate at each of the quarters.
What should I do next?
Re-calibrate the gauge to match the 100 Ohm sender.
Search for unobtainable original sender units, even malfunctioning ones, and
try to effect repairs.
Rely on a wooden dowel dip stick?
Any other suggestion?
Thanks.
_________________________________________
(______________ Alan Bromfield_______________)
(_______\____1957-BN4____/________)
(__tinyurl.com/healeyforum _)
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