Alternator Replacement

[march2021]

Can I replace the standard alternator on my '73 B with a new 18ACR without any modifications? Cheers
Dave Hornby

[JohnTwist]

The 1968 MGB uses a 15AC alternator with an external 4TR regulator.  Following that are 15 ACR (internal regulator), 16ACR, and finally an 18 ACR.  They are all interchangeable, EXCEPT for the plug variety.  There are two varieties of the three wire plugs:  narrow-wide-wide and narrow-extra wide-narrow.  Of course, you can change the spade terminal configuration by soldering different sized spades onto the wires.  The outside wire is BROWN/YELLOW, the center wire is the heavy gauge BROWN, and the inside wire is a sensing/feeder also BROWN.

Some owners have adapted a Saturn alternator which can produce 100 amps (you do NOT need 100 amps and even if you did, the wiring cannot handle it).

Hope this helps!

SAFETY FAST!
John H Twist
University Motors Online
www.universitymotorsltd.com