WallyP

And be absolutely certain to replace the ground strap BEFORE trying to crank the engine, or the meter is probably toast, or at least has burned an expensive little fuse.

Donald

Stan:
Have done all but EC grounds, the 14 pin was a mess; I re-soldered 3 or 4 of the pins and cleaned things up, will replace the connector when I have the part. I did not re-measure v, but I actually had movement on the dash gauge .

Jon:
Thanks, will try to do tomorrow when I have batteries for DMM #2 so as not to use the induction meter:

Wally:
You don't give me enough credit, I already took care of that item! In fairness to the mechanic me, DMM #1 has a 10a max (amps, mA, µA, whatever....) at least the fuse worked.

Finally- I did a quick search about pulling vital organs out of the alternator after Stan's brush comment, as I have the uninstalled rebuilt alternator on my bench, and saw this: https://rennlist.com/forums/7639476-post14.html
Here are pics of mine. To me it looks like refurb fail....

Mrmerlin

time for a new part there ( the whole shebang the armature is toast as is the brush set) Get a good quality rebuilt unit

Alan

Donald - sorry but you are going to have to forget measuring amps... its clear you don't really understand what you are doing.. It is possible to measure amps with the right tool and a DC clamp ammeter is the right tool in this case - however measuring current and matching it to specs is much more complicated than measuring voltage.

You can measure voltage at a few points on the 928 power distribution system and have relevant data to compare... and deduce from.

On current you don't really have this - and what current you measure on the car has almost no relevance to the alternator specs and is highly dependant on which bit of the supply circuit you measure.

Firstly:

There is no single place on a 928 where you can measure the total output of the alternator (without circuit modification). The battery ground doesn't work since non-charging alternator current returns only to the alternator case ground. The jump post includes supply current to the CE panel distribution (but not charging current), the main battery cable includes only the ~net battery charging current.

Secondly:

An alternator rated for say 110A could only ever demonstrate this current generation if you can present it with the neccesary supply load. On a car you have very limited options to control the load accurately - and have a battery that starts helping as the load increases and supply voltage drops...

Unless you really know what you are doing, have the right tools and fully understand the power supply topology from both a circuit design and physical layout perspective - measuring current will just give you confusing results and a big headache.

In general just measure voltages...!

If you absolutely wanted to measure total alternator amps - you must add a single short beefy pigtail between the alternator main B+ (30) termiinal to a new ring connector where the jump post and starter feeders can bolt up. Put your clamp meter around the new pigtail. This can only be considered a temp set-up for testing since this "floating terminal point" is quite dangerous loose in that location.

Alan

Mrmerlin

[QUOTE=Mrmerlin;7707552]So Don just to make things clear are you trying to measure voltage or amperage?? You should be looking for voltage so make sure you have the correct buttons pushed on your volt meter.
Alan, I already mentioned this as well, maybe you can break the ice

LT Texan

and then ignore the dash gauges and refer to the DMM.

Donald

Alan:
Thanks, very helpful.
Stan:
Trust me, you did get through!