MG T-ABC

TC Electrodynamic Experts,
Been wrestling with this box for 2 years. Had it transistorized. Battery registers 12.5v
1. D terminal shows 2-4v
2. F+D up to 32 v on hi rev
3. Manual settings with feeler adjusted for both regulator and cutout
4. Connect A+A1 and measure up to 35v on F and 12-13v on D.
5. Reconnect A and A1 wires to posts. Block off cutoff contacts and turn regulator top screw until 15-16v on F, about 12-13 on D. Regulator contacts are buzzing with a bit of white spark. Rev up and contacts will get sparky like a weld rod and F will go to 35v. Is regulator OK to spark like plugs all the time???
6. Adjusted cutout screw in and out without any degrade in voltage, but coil did energize and meet contacts.
7. Concerned it may be going haywire, even tho amps are only 3-4, I shut it down. But with key OFF, Ignition light is still on. If I screw down cutoff top screw coil will release and light goes OFF. BUT when I restart engine, light remains ON until I unscrew pressure so that coil has enough to close contacts.

I have read every thing I can find on the net and still can't get this right

Bob Wills

You had what transistorized? What brand?

Wilton Auto Electric converted Lucas RF95/2 to solid state. Generator is C45YV 13amp.

Sounds like from your description the RF95 you have is a standard mechanical points one, and not electronic. Got a picture of insides? An electronic one has no regulator or cutout points visible to arc like you describe.

First you may want to trace the F and the D wire back to generator. Bigger diameter wire is D or Dynamo output. Dynamo output charges the battery and supplies power for headlights and ignition, etc., through the regulator. Smaller wire is F or dynamo Field. Field wire only carries a small amount of current from the regulator.

You need to remove the small black bakelite cover on the dynamo body, where you will find a larger post and a smaller post for the 2 wires. Smaller post should have F wire, and larger post should have D wire. Originally the F wire at dynamo had a smaller lug that would only fit on the Field lug.

A good opportunity to check connections at dynamo.

Tell us what you find. Many people here run the standard mechanical regulator.

Duncan, thanks for trying to figure this out. The bakelite is in place. I also had the dynamo rebuilt at the same time. You are correct, I still have all the bobbins inplace. I also saw just today that Bob Jeffers who owned Wilton passed away July 2013. He worked on my regulator June 2013...bless his heart.
I am planning to order another RF95/2 solid state from Doug Pelton next week. Hopefully this will solve my concerns about driving the car and not knowing what is going on under the bonnet.

Duncan, looking back on your last post...I slid the dynamo cover band forward so I could verify D and F connections. F terminal wire goes to magnet on either side of the armature. D wires go to brushes. I thing that is correct.

Bob, I am suggesting your wires under the bakelite cover on dynamo may be reversed.

understand Duncan,
I will look further tomorrow and take photos.

Duncan, problem solved!! I reversed large yellow and small yellow with green stripe on generator posts. Both posts have same diameter bolt which is not correct. F is now 7-7.5v and on D is 16v when measured on regulator. Regulator bobbin now making and breaking contact at high rate without arcing. Ignition light now working properly. Thanks very much for your insight.
~Bob

Great news, Bob.

what a perfect example, how the forum can work miracles!