My 240z has had a problem starting after the installation of an MSD. The starter cranks very slowly. I went ahead and replaced the VR with a transistor type since it was the original and the problem is fixed. The problem now is that the ammeter jumps between half way and 45amps. It only does this when driving, not at idle. The lights and all are way brighter now, but I fear that maybe I'm killing my battery. The battery, however, doesn't even get hot. Does anyone have a clue what's going on here? Is the new VR bad? I'm thinking of putting it in my friend's 240 tonight to see if it does the same thing.

thanks for any help, Brian s.

The problem now is that the ammeter jumps between half way and 45amps. It only does this when driving, not at idle.

This may be perfectly normal. If the battery needs charging the needle will jump way up when driving and drop back down at idle.

does it go ALL THE WAY to 45? if so, it could fry your battery. it should stop about 1/8 inch from the 45.