Andy, Just a quick observation. If you are indeed running from the jumpstart post you have hot wired in 100% duty cycle. No alternator will last long in this configuration. If you are not careful you will fry your battery anything else as you are running open loop and the voltage will climb well in excess of 14.5 volts. Find out what is wrong and correct it. Look at the regulator first. Ron -----Original Message----- From: Andrew Smith [mailto:aos+yahoo@xxxx] I was experiencing very low voltage so I picked up the 150 amp alternator, but after installation I've run into a new problem: the field coil is getting no power.........In the meantime, I've hooked the field coil on the alternator directly to the jumpstart post (only while driving, so I don't drain my battery) and it works great.