How do you have the alt hooked up? Is the alt a single wire unit? Is the regulator a mechanical or electrical one, and you have the correct ballast resistor installed?

 

what is the brand and output of the new alternator?

 

If you changed the alt and nothing else you must ground one of the terminals on the dual field alt. Usually you just run one wire from one of the terminals[doesnt matter which one] to the back side of the alt case[maybe to one of the case bolts].This will ground the one terminal. Then you can hook up the alt. just like the original single field alt. Other than that, the only thing i can think of is that the original regulator is bad. It maybe marginal and then you add the newer alt.{mosdt likely with more output} and problems start to happen. Original regulators were not that reliable or accurate. they operated on a resistance principal and after a while they went bad. Age and excessive extra loads can take its toll on them. The whole original system on the 67 was only good for maybe 30 amps and if the vehicle sat around for a while without use, it just compounds the problem [excessive resistance caused by corrosion in connections]. I changed my reg over to a electronic one, it made a big difference on my 64 dart, got the wiring and reg at the junk yard. I would bypass the original amp gauge also.use volt meter instead.

 

heres a simple fix for the problem bill evans wire harnesses, 1-814-864-2622 .call the guy and tell him what car you have and that you want a motor harness for that car with the hookups for electronic ign. with new style alt. and voltage reg. its wired up to go right to your bulk head connector . itl like 125 a harness, iv used 4 harneses from him over the years and am totally satisfied with them. then you get the orange control box, and voltage reg. from summit racing. thats the fastest fix i know.hope this helps.

 

hey the thing to do if your in a bind is to just disconnect the original regulator. Find a regulator and "pigtail" {OEM plug and wire }. I like to use the plug and wire from an electronic regulator equipped dodge pickup because its easier to get more wire length. So, unwrap the electrical tape as far back as possible then cut the wire so you have a nice long length of wires to work with. The green wire on the "pigtail" goes to one of the field terminals on the alternator.[it doesn't matter which field terminal you connect it to !!!] The other wire on the pigtail [almost always blue colored] goes to a 12volt, key-on source. You could splice into the hot wire that originally went to your original electromechanical reg. or you could use a "jumper lug" {NAPA AUTO?} on the 12 volt, key-on terminal to your ballast resistor. The only thing left would be the other field terminal on the alt.. Surprise, that terminal is a 12volt key-on source also.Find a source and run a wire to that terminal. Leave the big wire on the alt alone and tap up{real good like} any of the hot wires you may have cut or disco'd. The original field wire from before you put the new ones on can be unhooked and tapped. Youll need a volt gauge, some crimpers and varios crimp style terminal ends of approriate size. Hope this helps:theomahamoparguy.