MG T-ABC

Decided to run 2190 today just to keep things moving. Started without a problem and ran perfectly for five minutes, then suddenly stopped. She’s lost all electrics, except for the starter motor and the clock, which are working perfectly……
I’ve checked all of the connections on the ammeter, regulator, ignition switch, etc, but all were tight with no obvious misplaced wires, blown fuses, or anything else amiss.
Has anybody else ever had something similar happen? Could it be the ammeter? Electrics is not my strong point, so a bit short of ideas.

Really difficult to diagnose remotely, but maybe check the battery and ground connections. The dash connections can be finicky sometimes so try wiggling each one and see if anything comes to life. Especially the back of the ignition / lighting switch.

I would check continuity with a meter,

Johnny grab yourself a test light (essential equipment with a TC) and see if you are getting power to the ammeter. There is a "heavy" wire from the battery to the ammeter which may be compromised.
The starter motor is wired direct to the battery and as it is working suggests that the battery is OK with eaththing or grounding etc.
If you don't have power to the ammeter run a "hot" wire bypassing the original, from the battery to the ammeter, and see if that reinstates power to the circuit. A length of domestic earth wire which is pretty thick should do the trick. If that works then you find out why the original wire isn't working. Perhaps a dirty connection at the battery or something like that.
Good luck
John Cockrem
TC2268

Thanks John, used your suggestion and discovered that I have power all the way through to terminal A on the regulator, but no further. I guess that means a faulty regulator, but I ran out of time to do any more today, but at least I feel I’m getting somewhere. Thanks for your help.

I hope you nail it Johnny. Might be worth looking at the back of the regulator. There some flat and I seem to remember soldered connectors that may be fractured.
A matter of persistence these electrical issues. I bet its something silly in the end....keep us posted.
Best wishes
John Cockrem

Decided to get to grips with the electrical problem today. Still no power at any other terminal than A on the regulator. Removed the regulator, but nothing obvious amiss on the back of it, so I removed and then replaced every wire on the connector block, making they were good and tight when I replaced them. That fixed it, all running normally again…. Strange how such an insignificant change can make a difference between working and not!

Those grub screw connections aren't the best thing ever invented. The ones on the back of the dash I was mentioning earlier have caused me trouble a couple times. Glad it was easy!