4drgl

I replaced fuel pump and got car running much better... now working on electrical problems. I have previously cleaned the ground post/ B+ post on the battery to a shiny silver gloss, and cleaned the strap, and the wing nut/bolt to which attaches the ground strap to the chassis. Battery is known to be in good shape.

So, with multimeter I determined the alternator was not putting out a full charge...11.5-12 vdc engine running which after 20 minutes left the battery at much less than a full charge on the battery...

So I cleaned all the contact posts on the alternator, replaced the green wire, cleaned the chassis to motor ground, and all the starter contacts up nicely. The motor cranked over quickly and easily. Much improved from previous...

With one exception the insulation on the B+ wiring was rubbed through on the alternator post and I couldn't find my heat shrink to recover it so I put the wire back and "Thought" I made sure the B+ wire was not contracting the alternator... however it somehow still made contact and now the alternator is not charging the battery period... It runs very well on the battery charger but if it's not plugged in the car runs till battery dies and that's it.

Now to pay the DF penalty.... am I looking at replacing the voltage regulator, new diodes? Or does the alternator need to go in and be rebuilt with all of the above???

1980 928, 4.5 litre w/automatic.

4drgl

hmmm please delete... unsure how I double posted..

Alan

Well - its likely all you damaged are the output diodes - take it to a GOOD alternatoir shop and they should be able to diagnose and replace only what you need.

Alan

4drgl

Boy did I bomb on that post.... WHOO... misspellings all over the place sorry....

WallyP

First thing to check - make sure that you have battery voltage between the alternator B+ post and chassis ground...

If not, you fried the wire between the B+ post and the starter battery connection.