[Healeys] Fuel Gauge Not Working BJ8

[BJ8 Healeys]

Hi, Jon -
The fuel gauge electrical circuit in a BJ8 provides about 90 ohms resistance
between the green/black wire and ground when the tank is full.  The reading
should be close to zero when the tank is empty.
The green wire provides the 12 volt input to the gauge, and the green/black
wire is the sending unit input.  The terminals on the back of the gauge are
marked T (for "Tank") and B (for "Battery").  As the gauge is installed in
the dash, the B terminal is outboard and the T terminal is inboard.

You do not want to short the gauge terminals together to check the needle.
You can check the operation of the gauge by removing the sending unit from
the tank and manually operating the float arm while monitoring the gauge.  
There is a good calibration/test procedure here, but note that it is for an
MG gauge which uses 68 ohms as the maximum resistance:
http://www.mgaguru.com/mgtech/electric/fg_10.htm

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 STOCKLAND at aol.com
Sent: Tuesday, May 26, 2009 12:01 PM
To: healeys at autox.team.net
Subject: [Healeys] Fuel Gauge Not Working BJ8

I have done some rewiring of the instruments and now find that the gas gage 
 is not working.  Have voltage to the gage but may have reversed the leads  
to the sender unit.  When the tank if full, does the sender unit show the  
least resistance?  If so, can I short across the instrument poles  going to 
the sender unit to show a full tank and see if the needle moves?
 
Thanks,
 
Jon