everytime I start my blazer the Battery guage reads low, and it stays that way until I "rap" the gas, and get the rpms up to about 2000. I have heard that this is quite common on older chevys, has any one else experienced this? and has anyone figured out a way to fix this? I have replaced all my wireing, (painless kit) and even upgraded to a "high output" alternator wireing package also from painless, and this hasn't changed anything. another question... Is there a thing as to much voltage? I have a slightly stronger than stock alt. its an 80amp alt and when I hook up the ol tester while the truck is running and i'm getting 15.1 volts at the battery. and when I flip the switch to charge both batteries at the same time, i get 14.8 volts at both batteries. is that ok voltage? or is that to much?