HudginJ3 wrote:

The 3G doesn’t have an external regulator. If you changeout the alternator and it still flashes the issue is the car or another bad alternator.

Sorry you misunderstood me. My first one worked for about 3 years, then on trip home it started to flash my dash ALT light sometimes off / on sometime it would just flash. The volt gauge stayed steady the whole trip. I changed it out with a new 3G when I got home and have never had problem again. I was thinking if it was the regulator I could replace it and have a spare alt for my next long road trip. They just unscrew with the brush pack. 

I would definitely give it a try.  My '89 GT had a previous conversion to a 3G, but as a matter of course I took it apart, blasted and painted the case and related parts and replaced the bearings and other serviceable parts.  I tested everything I could bench test too (not that I expected anything to be bad as I already knew it worked).  I think I had about $35 and my time in the rebuild.  I did my PS pump and AC compressor too. 

RTM wrote:

Rufus68 wrote:

The 3G voltage regulator is cheap enough that I would try it if I were you.  Also, if it were me I would order the "white" voltage regulator that has the built in delay to take stress off the belt when starting the car.

https://www.ebay.com/itm/384448367417?hash=item5982e88b39:g:xlIAAOSw2~9haZ1C&amdata=enc%3AAQAHAAAA8F%2Fx3lndmE0sFHqJPtgeCre6W4jrQ1YFF8dZFOaBXTrOX6EckYlhubb%2FAS5VcquBkIEy73Mb0cgRH2BpyBpUlwlGfa5KSlucA3cdpbUQ511nESETG8aLKU69LnE%2F8pkKIFCcSrW3qyQXjOsAUv1bpx4qprCblHf6E%2BGFmbfmJrdWuN925jIJ%2B7DnNPsZAbcrFQB%2FnJnNXUIKkbAZAvR5rHosljDlMgv%2BYg2Rif2ytSU8Nt7zxoifC2F1UJDLByGXgtbiv%2BZDeKqt%2BqLZ3mcvMzUAWW%2BhUmCAgva%2BxtADVcyjid8nw5jZfAy1zhbWZWgUrQ%3D%3D%7Ctkp%3ABk9SR9DHpdnNYQ

 
I never knew that this delay thing was an option.

Ford still uses this in some applications, this may be a regulator from a Diesel application.  Diesels have this feature because at start up you are placing incredible demand on the batteries and starter.  You are cranking an engine over that is 22:1 compression while heating the chambers by running the glow plugs, and stepping up battery voltage to 48 volts through the injector driver to fire the injectors.  The engine also has to spin fast enough to turn low pressure oil (engine oil pressure) into high pressure oil through the high pressure oil pump (have to hit 500psi or the injectors won't be commanded to fire).  Two 800+cca batteries in good health will go from 12.6V to 11.5V doing this dance.  Then the alternator comes online and you quickly get back to 14+V system voltage.  This is one reason I went to AGM batteries and upgraded the factory 130 amp alternator to a 175amp unit in my '06 F250.  Made a huge difference, especially when its cold. 

Got a new one coming. Went for the one w/o brushes as mine are fine. Likely a bad PC board? I will keep my old one too because if I need to swap alt on trip I know this one worked, just had a flickering ALT light. So with new reg it should work perfectly, if not I will have multi options.