I have a 1985 110 with a 200Tdi. currently the alternator light is on but if I measure voltage across the battery, I get about 13.7. Without the engine running the voltage is about 12.7. I wouldn't be too concerned but I have noticed that as the rpm increases the voltage across the battery increases also and I have measured it as much as 18 volts. Obviously there's a problem but I'm wondering 1) can I continue to drive it until I fix it?; 2) would there be any possibility that this is an external loose connection or short?
Any help will be greatly appreciated.