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MG MGB Technical - Wiring harness problem


I have just installed a new wiring harness in my 1964 MGB and am having trouble getting my generator to charge my battery. I have gone back and rechecked my harness connections and have found no problems. I am not able to get any voltage from my generator with or without the motor running. Could my harness not be correct? The generator was working when I started putting the new harness in. Has anyone found a porblem when installing a new harness in this old of a car? The harness was purchased from Moss. Can anyone give me any idea what to check?

Jim Walton

Hi Jim -

I installed a new harness in my '64 B when I rebuilt it, and have had no
problem with the generator...it works great. I'd go out and take a couple
of pictures of the wiring to show you what wires I have where, but I just
took it to my father'in-law's garage for storage while I build a new
garage. I bought my harness from Moss also.

Good luck!

Rich
http://64mgb.home.mchsi.com/
Rich F.

Jim did you polarize the generator when you hooked it up.You may want to check the regulator to see if that is ok.Just a couple of things you may want to check.
Good Luck,Tony
Tony

If it is the same generator/dynam you shouldn't have to polarise it, with a new harness it is almost certainly incorrect connections.

But first check the dynamo. Remove the wires from the F and D terminals, link them together, and connect a 20v voltmeter between the link and ground. Start the engine and *slowly* increase the revs watching the voltmeter. Don't let the volts rise above 20v, and this should happen before the engine reaches 1000rpm. If it doesn't the dynamo is faulty.

If that is OK double-check the wiring connections to the dynanmo, control box, warning light and solenoid by doing a continuity check, the schematics on http://www.mgb-stuff.org.uk may help, click on 'Spanners', 'Electrics', 'Schematics' and 'Dynamo/Alternator'.
Paul Hunt

This thread was discussed between 02/11/2002 and 04/11/2002

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