I have a 2002 Ram 1500 with 108,000 miles, have had literally no problems with it. I parked yesterday and killed the engine. When I tried to start it again, nothing happened. All power lost. I was able to jump it off but while driving around town, the entire instrument panel lights started flashing intermittently. All guages started lighting up. The battery indicator would skyrocket to high, then suddeny drop. Lights began to flicker. I came to a stoplight and it suddenly died,...no power. It seems obvious that my battery is not getting charged which might lead me to believe its a bad alternator, but I took off the negative cable and the engine did not die. What is really wierd is the light show I get when I rev the engine up to about 2000 rpm's. Everything imaginable flickers. Could it be a bad connection? If so, where? I've already cleaned the battery posts. I've also checked the wires between the alternator and the battery for continuity with no problems. Could it be a bad connection from the battery to the starter? HELP!

 

How old is the battery? Id start by bench testing both the alternator and the battery. Most autoparts stores do it for free. Just because the alternator is charging doesn't mean the internal voltage regulator is working.

 

Same thing happened to my 2002 at about 80,000 miles. It needed a new battery, problem solved.

 

Taking off the negative cable to see if the alternator is good or bad is for the old days. Todays vehicles run mostly on the computer, so if you disconnect the battery it is not going to run. IF you were driving a 1970 vehicle this would work but unfortunatley today our world is ran on computers and the computer needs the battery to run the vehicle.