I recently went to gas up my 72 mustang and when I went to restart it, the battery was not strong enough. The battery is less than 3 months old. Then I noticed the Alt gauge was flat on the D. So I changed the alternator and the voltage regulator. It did not fix it. When car is running and I pull the negative from the battery it instantly dies. Now the alternator light is on too. When I check the voltage to the regulator the ignition wire only shows 1.6 volts. Everything else is 12.5. I feel like it might be a wire issue. Any suggestions on where to look next are appreciated. Thanks in advance.