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MG MGB Technical - common wire

Hi everyone. When I parked this car before Christmas, the fuel gauge and tach were working properly. After replacing several gaskets I took her out for a spin and noted that my tach and fuel gauge were not operating. Is it possible I could have dislodged a wire common to both gauges which would render them inoperative?
Keith Yarbrough(TD 1275)

Sorry, this is on a '71B
Keith Yarbrough(TD 1275)

Tach and fuel are on the green line which is from fuses to a 'join' then splits to both. That's the common point. If you indicators work then you need that junction. If no flashers then its before
Bernie
B Anderson

thank you for your help Bernie
Keith Yarbrough(TD 1275)

For future reference the diagrams here:
http://www.advanceautowire.com/mgb.pdf

Are worth printing, laminating and keeping handy :)
I have found them invaluable and MUCH easier than the dreaded Haynes and WS manual spider webs
Bernie
B Anderson

Is this a UK-spec 71 or a North American? North American (the writer being from California) had electric temp and fuel gauges, so if the problem is a common wire feeding the tach and the voltage stabiliser all three would stop working. Also the feed to those came off the electric oil gauge, so if that is working the fault is between the oil gauge and the tach. If the oil gauge isn't working either but the indicators are, then the problem is between a 4-way bullet behind the dash and the oil gauge. If the indicators aren't working either then it's between the fusebox and that 4-way bullet.

For a UK 71 only the tach and fuel are electric of course, but again if the indicators are working it's between a 4-way bullet and the voltage stabiliser, if they aren't working either then it's between the fusebox and that 4-way bullet.

Incidentally neither the tach or the oil gauge are fed *from* the voltage stabiliser, it's just used as a branching point for the green, fused ignition, wire.
PaulH Solihull

I haven't been tinkering under the dash so I'm thinking I dislodged something under the bonnet while I was removing the heater unit. The PO had stated that it leaked so I wanted to check it thoroughly before running water through it. Haven't had a chance to check that as I've been working this weekend. Thanks for all the information.
Keith Yarbrough(TD 1275)

This thread was discussed between 16/02/2013 and 17/02/2013

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