MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - voltage regulator sparking

I've just fitted a new voltage regulator on my '58 MG Magnette, and having also overhauled the dynamo I can now enjoy headlights and heat/blower without draining the battery. However I noticed when testing the regulator that there's a very small but visible continuous spark from the points when the voltage has reached the set limit. I never saw this with the old setup, but I suspect it was sufficiently worn or corroded that the current never got high enough to trouble the regulator. It seems reasonable that the points would be cycling continuously, but has anyone noticed the sparking, and is it likely to cause long-term wear ? As I understand it, the resistor connected across the points is intended to prevent arcing.
stephen

Stephen - While the resistor across the points will provide a certain amount of arc suppression, it's main function is to tlimit the current through the field coils, thus limiting the output of the regulator. I would guess that a certain amount of arcing fromt he points is normal, but I really can't say for sure as I have never noticed it on our TD (but then the last time I had the cover off of the regulator was several years ago - as in 5 to 10 years ago). Someone who may be able to answer your question more precicely is Bob Jefferts at bobj20@adelphia.net. Bob makes solid state regulators, built right into the original housings and calibrates them for the generator that is used in your car. Good luck - Dave
David DuBois

This thread was discussed between 28/11/2005 and 29/11/2005

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.