Alternator, Before I Drop the Engine Options

[martinef1963]

Okay - this is my last plea for solutions before I have to drop the engine and replace the alternator on my 72 teener.

I've checked the tightness of the belt for possible slipping - and it's fine.

Replaced the Voltage Regulator and still get the alternator red idiot light on my panel. The battery is shot because the alternator is not charging it. I put a jump on it and it runs fine, but when I take the cables off - it will run until the engine dies (radio won't work, and only left headlight unit will come up). (IMG:http://www.914world.com/bbs2/html/emoticons/ar15.gif)

Is there anything that I might be missing - or is there a sure fire way of testing the alternator to identify it as the "actual perpetrator?"

As usual - I value your 914 wisdom.

[bondo]

Check all your connections, including ground straps. Also, a toasted battery may not take a charge so your alternator may be fine. A completely toasted battery is like an open circuit... if it's that bad then disconnecting the jumper cables while the engine is running is like disconnecting the battery, which may fry the diodes in the alternator. Moral of the story: Always test the charging system with a known good and charged battery.