In a message dated 97-07-30 18:42:58 EDT, up497@freenet.victoria.bc.ca (John
L. Walker) writes:
> It's just that in my car, the brown/yellow wire (from alternator) is the
> larger (10 ga?) wire, and the brown/green wire is smaller (14/16 ga?)
Malcolm:
Is it possible that the Brown/Yellow wire is actually Brown/White, but the
white has yellowed with age, and the Brown/Green is actually Brown/Yellow,
but looks green because of grease and dirt? Early TR6 models used a
Brown/White wire from the ammeter to the alternator. Maybe whoever installed
your GM alternator used wiring from a TR6, which had an alternator?
Anyway, it is now time for draconian measures!
BottomLine!!!!
The large lug on the back of the GM unit should have a large wire (largest
wire in the car, except for the battery cables) connected between it and the
battery positive post. This connection is usually made at the starter
solenoid for convenience sake, but if you have a connection available, you
can connect it directly to the battery.
Terminal # 2 can be connected directly to the large screw terminal with the
large wire above.
Terminal # 1 should be connected to a source of power that is hot only when
the key is on, and should have a small lamp in series with it. The source of
power can be any wire that's hot with ignition on, it doesn't have to be at
the back of the switch. You must have a lamp in series, or use a diode wired
to conduct from the ignition switch TOWARDS terminal #1, or use a 15 ohm
resister in place of the lamp. If you connect terminal #1 direct without the
lamp/diode/resister, the car will not shut off when you turn off the key. I
don't know offhand what size diode to use, or what wattage resister to use,
so I would recomend the lamp.
That is all that is required to get the charging circuit working. All the
other wires need to be connected as required to get the other devices in the
car to work.
That's why I put the warning at the end of the alternator instructions - who
knows what modifications have been made to these cars over the years!
Dan Masters,
Alcoa, TN
'71 TR6---------3000mile/year driver, fully restored
'71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
http://www.sky.net/~boballen/mg/Masters/
'74 MGBGT---3000mile/year driver, original condition
'68 MGBGT---organ donor for the '74
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