This morning my 02 Expy started fine no problems whatsoever. I get to work park, make sure no lights are on and leave. Come back 8 hours later truck won't start. None of the electronics work. All I hear is a ticking sound coming driver side somewhere under the dashboard. I was sure no lights were left on. So I get it jumped started. Fired right up. Drove around for about 45 minutes and made a stop at the auto store. Get back to the truck and no power again. So I buy a brand new battery. Put it in and guess what. That's right no power again. I had to jump once again. One of the mechanics at the auto store said I might have a short somewhere. So I drove the truck home. Any clues on what is going on with my Expy. I thought it would be the alternator but since I just put a brand new battery in. That eliminates that possibility.

 

Verify alternator operation with a meter.

Use the ammeter function of the meter to check for any parasitic current drain that may be draing the battery (if that is what is happening, you need to do some more diagnostics).

Steve

 

I just put a brand new battery in. It couldn't be more than 30 seconds from the time I tighten the connectors to the time I try to start the vehicle. Can I test the alternator without taking it out.

 

It sounds as though you have a diode or 2 bad in your alternator.

 

With just putting in a new battery, it seems to be requiring more amps to kick it over or to jump a bad connection. I would check the connections at the relay and comming off of the relay, then the starter. That new battery should have started the truck.

 

I would agree with Omahastro1 . It is probably a connection . The battery end of these battery cables are a little on the flimsey side, where the cable bolts on to the battery post clamp. I would start there, and then on to where the neg cable bolts to ground .