hey fellow GM folks.

we have a 2003 suburban 5.3 one day it would not crank. no turn over at all. after a day of troubleshooting we think it was the security system because we can jump the starter relay and start the truck. that was hit and miss and then one day we noticed the blower would not blow, the transmission would not shift into overdrive and the abs and brake lights stays on all the time. some times it will start with the key and the ac won't work. sometimes we have to use the jumper and the ac works or wont work. sometime everything works as its supposed to.

it has always started, it might have to have that jumper over the starter relay but it has never stranded us.

we replaced the ecm, the ignition, the battery, and thats all. any help would be welcomed. we have a big family and love this rig. i want to keep a chevy in the driveway. this is my first LS.

is it a ground?

 

Welcome to the forum. Intermittent ground was my first thought as I was reading your post.