ammeter

No, you should be O.K. But here is a tip: Get rid of the ammeter, they just cause problems. Easy way is to run a 10 gage wire from the alternator lug right to the + battery (at the starter solenoid, is usually easiest spot). Just make sure it has a fusible link in the wire somewhere. This bypasses the ammeter and all the crummy old stock wiring. Then install a voltmeter... they tell you a lot more about the car's electrical system anyways.