MGB Electrical Problems

[R34fanatic]

I have a '71 MGB roadster with some electrical issues. I put in a new, fully charged battery, after finding the original dead and dry. The car runs fine and did for the whole week. But after some normal driving, the power gradually began to fail. The car continues to die until the engine shuts off. A quick recharge and it's back to life. Replaced the alternator, has new spark plugs and coil.

Any suggestions greatly appreciated.
Thanks again.

[KimMG]

Check your battery cables making sure the connections are clean and secure (both ends). Make sure all the connections at the starter are clean and secure. Check you belt make sure it is not slipping. Test the output of your alternator (new doesn't necessarily mean good). Make sure all the alternator connections are good.
Dan Masters drew some good wiring diagrams and they are available at advanceautowire.com. Make an enlarged copy for yourself, it will help in tracing problems.
The following two sites have good technical articles:
mgbexperience.com
britishcarforum.com

[R34fanatic]

Thanks. Will probably have to check the whole harness to spot the problem, though....

[MGBSS63]

IF IT'S NOT YOUR ALTERNATOR OR WEAK BATTERY CHECK FOR VOLTAGE DRAIN...Disconnect negative cable off battery put volt meter between negative cable and battery post shouldn't be any voltage reading....If there is start diconnecting one componet at a time and recheck voltage till you find problem....mgbss63

[SIKO]

Make Ure Your Alter. Is Charging. I Had A Post Broken And My Mg Would Do He Same Thing