So I installed a 280ZX alternator in my 240Z

[Jehannum]

Blue, thanks.  I've been following that thread as I noticed it was at the top in a timely fashion.

 

I noticed I'm not running a capacitor on either the harness side (where the regulator was disconnected) or the alternator side.  I read that most don't run them as they only filter out static in the wire.  I'm hoping that's accurate as I successfully tossed the old ones. 

 

Zed,

 

The wire is not totally destroyed but it is pretty toast.  I need to trace it back through the loom to see how far it was affected.  It certainly got VERY hot.   I'm not sure how to test for a shorted circuit in the ground system ~ but I am sure that there wasn't any issue until I was actually cranking the motor over.

 

Any information on how to read my wiring since the gauges seem to be from a differing setup than all of the '72 wiring diagrams I've found?  The ammeter seems to ground with the other gauges at the wiring harness that grounds near the starter?  My starter is grounded to the wiring harness's ground point on the right frame rail through a grounding strap.

When that happened to me, the ammeter turned into a make-shift fusible link.  It burned up, but the harness remained intact.

[cnwayland]

When that happened to me, the ammeter turned into a make-shift fusible link.  It burned up, but the harness remained intact.

 

It sounds like you figured it out already..?

For anyone else with similar issues, I think two things: check the harness plug before just popping in the voltage regulator delete plug, and redundant grounding.

Edited March 26, 2015 by cnwayland

[Jehannum]

It sounds like you figured it out already..?

For anyone else with similar issues, I think two things: check the harness plug before just popping in the voltage regulator delete plug, and redundant grounding.

Yeah, on mine the cause was that the coolant junction above the starter started leaking, and the hot wire (white) that ran from the old ammeter (which doesn't convey any useful information after switching to an internally regulated alternator) to the starter was shorting to ground through the coolant.

 

That let all the magic smoke in the ammeter out in a hurry.

 

I didn't bother with the delete plug, I cut everything back to the harness and ran it correctly to the alternator or looped it.  Much cleaner, IMO.

Edited March 26, 2015 by Jehannum