2003 Chevy Express Short on positive battery cable

GREGLOYA

MEMBER
2003 CHEVROLET EXPRESS
V8
2WD
AUTOMATIC
80,000 MILES

Van was driving fine. It sat in the cold for a week. Tried to start - completely dead. Put charger on battery - this overloaded the charger (pegged the needle). Ohn reading from pos bat terminal to ground is zero. Cut the three wires at the terminal to isolate. Disconnected alternator - no short. Short seems to be on the red wire that does to the fuse block. If I connect power to the high amp side of the starter, it clicks! Took the stater out, thinking it was shorted - bench test was fine. Power on high amp wire - nothing, power on coil made the piston shoot out. If I remove the 30 "pwr seat" breaker from the fuse block, the short on the fuse block seems to go away (but the ohmmeter does start to short and then shows open). Took out starter relay in fuse box - starter still clicking with no key in with power on high amp side (where battery would be attached.) How is solenoid activating with starter relay removed? Is it the PCM?

1 Reply

HMAC300

MECHANIC
48,601 POSTS

First things first. Charge the battery with the cables disconnected. An OHMmeter will read zero with the positive connected to cable and the negative to ground. It should. If it was set at volts then it should have read battery voltage. Then reconnect the wires you cut. Then leave the pwr seatrelay out and put a test light from the cable to the battery post. Do this with the key off. If the test light lights you have a draw. If not it should be able to connect with no problem. Try each circuit until the light goes out. That is the circuit that is giving you the problem. But check for a dome light left on, courtesy lights left on, etc. If it was cold- below freezing with a dead battery there is a good chance it is frozen if it is it's junk. As far as solenoid activating yu may have two wires touching or nuetral safety switch messed up.