400 12volt conversion assistance

I bought a 400 that was converted to 12 volts started and ran good. But did not charge the batttery.
I changed the generator to alternator 1 wire. Removed VR and spliced the battery wire to the one coming from the alternator.
Now I have voltage on both sides of the Amp. gauges, no voltage on any position of starter switch along with no starter cranking but voltage at postive side starter, no voltage at solenoid.
Help what did I do wrong this time?

Your generator voltage regulator probably had an L terminal that fed the ignition/light switches. Alternator does not have that terminal. Just connect your switch power sources that were connected to the L terminal to the alternator side of the ammeter.

Assuming you changed the battery such that the negitive was ground.
The method you used seems OK but the reason it didn't charge befor might be thre reason it is not working now.
1) disconnect the one wire system at the bat wire where you spliced it.
(and assuming you didn't change the amp meter wiring)
2) Correcting the amp gauge to read correctly. Remove the lead from the amp gauge that goes to the starter relay (you called it a solenoid)
that wire should be Positive and hot at all times, so be careful with it.
Remove the multiple wires from the other terminal of the amp gauge, and put them on the other terminal.
Put the wire from the starter relay on the empty terminal.
The Bat wire that was disconnected above should be connected at the dash, to the amp gauge among the multiple wires you changed. Make sure it is with an Ohm meter.
If the old voltage regulator had a "L" terminal, that wire should be connected to the Bat wire where you disconnected it along with the Bat wire.(above)
So from the alt the wire should go to both the Former L wire, and the Bat wire.
Try it.

If the one wire was connected to the battery when the battery was Positive ground, it will probably be toast. Best of luck, Jim
Keep us informed.

It was negative ground 12 volt conversion before I replaced the generator and voltage regulator.
Thank you for your help John