Amp.gauge quit

[WorkinLonghorn]

OK,it had some help. I had a situation where the alternator would not charge unless I rev-d the engine way up before driving.Then I would get charging until next start-up.If I forgot to rev it up then the truck would just run on battery until dead. Took the regulator back to Autozoneout and it checked out good.I checked all wires and took the wires off the little black junction box by the battery and cleaned them up.Replaced the main red wire that runs along the top of the radiator because the insulation was bad.
>>now it seems to be charging but the Amp gauge is not working. I can't see from the wiring diagrams what I could have done wrong.It doesn't make sense.
>>So how does the wiring go to/from the amp gauge? Maybe I'll just run new wires,or trace the old ones. Much thanks-Brian