It could also be the wiring.
Briefly connect a ground to the green/blue at the gauge. If the needle
starts moving smartly towards Full the gauge is OK. Now do the same with
the same wire at the transmitter. If you get the same result that part of
the wiring is OK.
The transmitter should have two wires - the blue/green to the gauge and a
black (ground). Diagrams for some years show this as having its own
grounding point on the car, others show it sharing the grounding point with
the rear light clusters, reversing lights and fuel pump in the boot. If you
can jumper a good ground to the base-plate of the trasmitter, or it you can
measure a switched 12v on the base-plate, then the ground is bad. If
neither of these is the case then it looks like the transmitter is bad.
PaulH.
http://freespace.virgin.net/paul.hunt1/
-----Original Message-----
From: Steve Conley <swconley@foxinternet.net>
To: Chris and Jodi Barnhart <barnhart@geneseo.net>
Cc: MG LIST <mgs@autox.team.net>
Date: 29 March 1999 04:56
Subject: RE: Oil pressure sender
>I have a somewhat related question:
>I am trying to troubleshoot why my gas gauge is kaput. I read that often
>the problem is the fuel tank sending unit. If that is indeed the case, how
>do I test to see if it is the sending unit or the gauge itself? (hoping for
>the cheaper alternative - sending unit) Also, when I looked at the sending
>unit, there are 2 terminal connectors, but only 1 has a wire attached. This
>may be a stupid question, but are both supposed to be connected to
>something? If so, what connection may be missing?
>
>Thank you,
>
>Steve Conley
>Marysville, WA USA
>'76 MGB Roadster
>GHN5UG393585G
>mailto:swconley@foxinternet.net
>MGB Online = http://web3.foxinternet.net/swconley
>
>
>
>-----Original Message-----
>From: owner-mgs@autox.team.net [mailto:owner-mgs@autox.team.net]On
>Behalf Of Chris and Jodi Barnhart
>Sent: Sunday, March 28, 1999 7:13 PM
>To: mgsautoxteamnet
>Subject: Oil pressure sender
>
>
>Hi all,
>
>Now that the car is running I working through some electrical problems.
>Managed to determine the cause of my malfunctioning water temperature
>and gas gauge today (bad voltage stabilizer). Also found out I have a
>faulty oil pressure sender. A couple questions:
>
>1. What should the resistance of the sender be at rest? (mine shows
>infinite currently)
>2. Anyone ever replace a oil pressure sender on a '69 B with a modern
>sender unit? (Or if I know the resistance I can cross ref to one)
>3. One wiring diagram I have (Haynes) shows the oil gauge to be fed
>power from the voltage stabilizer. Mine is fed from a green wire on the
>"B" side of the stabilizer (not regulated) which is consistent with the
>factory workshop manual. Since I have seen it both ways I am curious if
>the oil pressure gauge should have regulated power. Thoughts?
>
>So many questions.
>Thanks,
>Chris
>
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