My 02 Avalanche had a dead battery this morning. After a boost, it was idling poorly and stalled. I got it going with a boost again and moved it to my shop. It stalled again, I opened the door, which normally kills everything still on, radio etc. but the blower motor would run for about a second, shut off and do it again. Literally sounds like it's breathing!. With the charger on and I try and start it, the dash looks like a light show, with everything flashing on and off. WE had a lot of rain in the past couple of days, I suspect water has gotten in somewhere. Any ideas wgere tostart????