The Zoomboni has a dead alternator.

So the Zoomboni of ridiculousness came to me after sitting for a decade and the battery was missing.  I dropped in a new one and it fired right up.  It also fired right up each time I tried it over the winter but last week it went "click click" when I asked it to.  Jumped it off and let it run for a bit thinking it just hadn't started in a few weeks.  Then yesterday I tried again and got the click click.   E36 M3.

Jumped it again and read 10 volts across the battery.  Turned on the radiator fan and that dropped to 8.  Shut it off and it bounced up to 11.   Sounds like I'm running on straight battery and the alternator isn't doing anything.

Drivetrain is stock 1988 Mustang 5.0 with that external fan old school alternator.  Is there any other test I should be doing and what drop in part do I want to order if it is indeed a dead alternator (probably has been for years but, you know, race car)

Replacing parts is easy, diagnostics is hard (for me).  Thanks gang.

Start it and see if voltage at the battery goes to 14. If not bad alternator. 

Don't forget to check the plug at the alternator. Older ford units tend to burn up.

Check the plug, make sure you have battery voltage at the main wires, make sure the dash light glows, key on engine off.

In reply to Streetwiseguy :

dash lights.....keys.....nope.

Annoyingly this era ford has the stupid alternator with two blocks of wires that plug into it.  Not a simple main power cable and ground like a sensible car.

The stupid plug is what melts sometimes.

In reply to KyAllroad (Jeremy) :

The load/excite current from the dash light needs to be hooked up or there will be no charging. 

Considering the bare bones nature of it, you could probably downsize the alternator 

Your local shop that repairs electric motors can probably get you a 1 wire alternator for around $120. That's what is on my race car, replacing the $230 alternator from Pegasus and it looks identical.

Depending on what's wrong with the alternator (if it is the alternator, it could be a bad battery or something else) it may be able to be rebuilt for a few dollars.  No sense in changing it to something else that requires redoing the wiring harness if you don' have to.

Make sure it has a load/excite wire. Get the unit bench tested before you condemn it. Bad wiring is just as good a possibility.

Autozone, being the awesome folks that they are, attempted to test the alternator but apparently were missing the exact dongle needed to hook it up.  So I just ordered a new one which I can return if it doesn't work.    Simple enough I suppose.   
 

I still hate diagnostics.  

On many high hour alternators a new set of brushes is often all that is needed.

update.   So new alternator went on today.  Jumped it up and still no charge coming across the alternator.   So since I still SUCK at diagnostics I really need to be spoon fed some wisdom here.  This block is on the positive side of the battery.  Should it have continuity?  What is it called?

Help me out, I hate being stupid.

If you really have help to offer or can walk me through what to test, give me a call 8five9-6ninenine-8three43.

In reply to KyAllroad (Jeremy) :

That is a Ford Starter Solenoid.  Generally a bad one will lead to no cranking, not no charging

I can't remember exactly what continuity looks like around the posts, but here is a generic image.

In reply to Mr_Asa :

Ah.  Well E36 M3 it starts right up.  Just not charging at all.  Frustrating.

Did you replace the alternator or the solenoid pictured?

What year is the engine from?  Have you found a wiring diagram to go through?

1988 Mustang motor and harness.  I replaced the alternator and the battery with new.  No charging appears to be occurring while the engine is running.  
 

Here's a full diagram

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Immediate thought is, do you have the regulator? Has it been checked?

In reply to Mr_Asa :

I know you're trying to be helpful man but this is indecipherable to me.  I'm just gonna pay someone to look at it because apparently I'm stupid and this sort of job just frustrates me.

Looking at the diagram the next check is at the regulator as Mr_Asa pointed out. 

In reply to KyAllroad (Jeremy) :

Nah man, it isnt that bad.  We all have jobs we hate, that's why you figure out how to do them so you can get them behind you as fast as possible. 

Take a look at the second post here.  It seems to be fairly comprehensive. 

https://www.stangnet.com/mustang-forums/threads/2g-alternator-wiring.899799/

Yup, that makes no sense.  I'm hell on swapping out suspension parts and I can find my way around brakes and hard parts pretty well.  But chasing electrons and diagnostics seems to be another language.  Thanks though.

Ok, one last try.  Key on. Engine off

Measure the voltage of everything going into the alternator and the voltage regulator.  Report those, we'll go from there.