I recently moved the battery from = the engine compartment to under the rear seat. New heavy gauge battery = cables, new battery, new belts etc. Suddenly the new voltmeter on = the dash starts giving strange readings. When the van starts, I get 10 = volts, after it comes off idle, it will come up to 12 slowly, then after a few = seconds of higher rpm it will come up to 14 volts slowly. If I turn the = lights on down to 13 volts. If I turn the heater fan on down to 12 volts or lower. Obviously if I hit anything else even lower. Thinking = I had a bad alternator, I replaced the 65 amp model with a 90 amp Quantum alternator. Same symptoms. Thinking that maybe the primary = lead from the alternator to the battery was too small for the job I bought some 6 = guage multi-strand (1/4 inch in diamter) and soldered on some heavy copper lug = terminals. Same symptoms. The battery has a good ground to = the body, as does the alternator, and the engine itself. Oh by the way, it's = not just the gauge. When I turn on the lights at night, and then turn = on the heater fan the lights dim noticably. I think with a 90 amp = alternator I ought to be able to power all the lights and heater fans I want and = still have juice to spare. And one last thing, the local parts store tested = both alternators and their machine said they were operating just = fine.