Hi List,
I keep thinking with all these years of experience troubleshooting and
fixing MG electrical problems that I'll get to the point where one
doesn't stump me and I can fix it without asking for help. That just
hasn't happened yet.
The latest is a problem with the battery draining while the car is
stopped and off. At first, if you left the car not running for 2 days
(rainy days), it turned slowly and wouldn't start. Now if I leave it
several hours it turns slowly. I've had the battery in to the auto
parts store and it's good - only 4 months old.
Troubleshooting yesterday, I pulled off the ground cable on the battery
and hooked up the multi meter between the cable and the (-) terminal on
the battery to see if I was bleeding off power. Sure enough, it showed
12 volts. Disconnected the new electric fans, since that was the last
thing changed before the problem started, but still showed 12 volts
between the cable and the post. Started pulling out fuses one by one
and the 12 volts stayed on until I pulled out the bottom fuse, the one
with the brown wires in and purple wires out - the circuits that work
when the key is off. Finally the voltage dropped to 0 with that fuse
out. Pretty simple - buzzer, boot light, interior light with the doors open.
Put the fuse back in - got 12 volts again. Opened the boot, removed the
bulb from the boot light, and the 12 volts dropped off. Light in, 12
volts again. Cycled the switch a few times and put the bulb back in.
Now the switch controlled whether the 12 volts was on or off.
Reconnected the (-) cable to the battery - light on with switch up,
light off with switch down. Light on with boot lid up. Closed the boot
lid, disconnected the (-) cable, and no voltage flowing. Pretty happy
with myself with such a quick fix.
Little while later we went to start the car and it turned slowly again,
but the battery had been disconnected since the last time I drove it so
it should have been fine. Charged it for awhile, started the car, drove
around, shut down, disconnected the (-) cable again, and 12 volts is
showing again.
Took out the fuse box and cleaned all the contacts thoroughly. Put it
all back together, checked for no voltage at the battery cable and it's
all good. Charged the battery for 5 hours, disconnected it to go to
bed, then got up this morning and the battery is weak again. I'm at a
loss as to what to do now, so I just took out the bottom fuse - brown in
and purple out, and I'll just live without the key off things for awhile
until I think of something else clever to do.
Any help on this problem would be appreciated.
Cheers,
Rick 'stumped in Baton Rouge' Huber
'75 V8 B Daily Driver (after an every morning battery recharge)
'65 B undergoing lengthy restoration
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