Hi everyone, after lurking a little while, I finally had to make an account and ask for some advice. I'm trying to get this '08 Hummer H3 3.7l back on the road after 4 years of sitting. I checked all wiring harnesses & changed the oil, threw in some fuel stabilizer/Heet, and put in a new battery. It originally cranked but would never start so I assumed it's probably bad gas as it's been sitting for 4 years.I disconnected the battery for a week, and then I siphoned all the gas out by going under the truck and pulling the fuel filler hose from the tank. I put 5 new gallons in the tank, and then reconnected the battery. When I put the key in, the fuel pump doesn't engage, and it does the door chime 4 times, and then repeats every couple of minutes. Everything lights up, and works. I tried connecting my code reader and it keeps showing no connection. I was thinking it could be a fuel pump, but I'm not sure as it was working last week & my code reader will no longer work so I feel it might be electrical. Any help is needed! Thank you

 

So, last week you could communicate with pcm through datalink?
we're there dtc's at that time?
was the vehicle kranking?

 

I'd start at the fuse box and verify with a test to each fuse (one at a time lol) visually and with dvm that they are known good.
I'd verify each relay was good.
I'd make d@mn sure that main circuitry was good.
You can connect a remote switch to starter to test if it indeed turns engine over. In park lol.

 

You can jumper relay/fuse for fuel pump to test if it will activate.

 

hopefully critters have not chewed your harness wires. also check your body ground points for corrosion. especially if it was sitting on dirt or moist shaded area for the 4 years.

 

Is the "new battery" fully charged?

Are you still trying to use the Crappy Azzed OEM Battery Terminal Connectors? If so, hack them off and replace with a quality aftermarket set like Stingers or your favorite brand.