I got a 68 Barracuda the voltage regulator smokes after about a minute of running. Ive change the alternator voltage regulator starter relay clean the bulkhead connections bypass the ballast resistor how can I troubleshoot this problem I've checked continuity to ground everything seems to check out. I'm running a pertronix 3 distributor

Assuming you are still using the stock mechanical regulator, if you look at the back you'll see two resistors. The smoke you see is probably from one of them being overheated. Try starting the car with the field lead to the alternator disconnected. Still smoke, PROBABLY the regulator. No smoke, PROBABLY the alternator. I'd still have both checked before I started replacing parts willy nilly.

You changed the reg & the new one is smokeing like the old one did?

Won't smoke with the field disconnected I've already changed the alternator and voltage regulator. The first vr the red wire before it gets to where it's wrapped was getting hot looks like the replacement is doing the same

Yep

Okay, are you using the stock mechanical regulator or the aftermarket solid state unit? Within the first minute before you get the smoking, what is your ammeter reading?

Stock mechanical and im not 100% sure but the ammeter gauge was charging

I'm a little confused when you mention the red voltage regulator wire. The standard voltage regulator color codes for that era were green for the field lead and dark blue for the ignition lead. Has your car been re-wired?

Sorry i didn't clarify myself. I took the cover off the voltage regulator and the thin red wire under that is what got hot. Then it's winds around Inside the vr

It sounds like a short to ground in the field of the alternator.

R.

yeah that's what it sounds like but I got a different alternator and it's still doing it and I check for continuity on the field wire and it's not going to ground

Have you checked the field wire where it runs along the valve cover for a short to ground?

That's why I asked what your ammeter read. All the symptoms point to excessive field current. If the voltage regulator is good AND grounded AND the alternator is known to be good, then it sounds like the alternator is running close to being full fielded. I'm thinking that this could be due to a huge system electrical load OR the sense voltage at the regulator is low for some reason. What is the voltage reading at the IGN terminal with the engine running? Should be pretty close to battery voltage.

We're missing some info here. if the reg/alt are good/grounded, green reg to alt wire ain't grounded, batt is charged up then it must charge normal. I would check that green wire like John said then ohm/check the alt field circuit/terminals even tho they said it was fine.

I'll check the reading on green field wire at the vr again but I'm pretty sure it was very low

You would sure think the field wire was shorting out but my meter says it wasnt

I'm thinking the "points" on the new reg are sticking or it is misadjusted (I'm assuming this is an electromechanical reg with the 2 wire wound resistors like in the above pic). I would get a replacement "electronic" reg at your parts house. Though you might do a good visual on the green field wire for any potential bare wire dead short & pay extra attention to the terminal at the alt. If any doubt regarding it I would take off the green field wire & with a jumper wire with alligator clips, jump from the reg to the alt field.

Yep I was just thinking that myself

Yes, the fact that it takes a minute for it to act up is what Sherlock Holmes would call a (serious) clue. (I missed it initially).