NEED HELP Cranks but won't start

[Judithspring41 l]

So I bought an 05 Trailblazer that was wrecked in the front crank up and drove fine I drove it home everything was great I was just going to replace the front bumper and the hood in the grill it set for about 3 weeks I went out to crank it and it wouldn't fire I searched around underneath the hood and found a Rat's Nest by the fuel injector sensor wires so I replaced all of those and the Trailblazer is still not turning over I'm not a mechanic by no means I am a single mother trying to make do with YouTube videos and just common knowledge so I did hook it up to a computer and I have no codes that it's reading out

 

[TJBaker57]

So I bought an 05 Trailblazer that was wrecked in the front crank up and drove fine I drove it home everything was great I was just going to replace the front bumper and the hood in the grill it set for about 3 weeks I went out to crank it and it wouldn't fire I searched around underneath the hood and found a Rat's Nest by the fuel injector sensor wires so I replaced all of those and the Trailblazer is still not turning over I'm not a mechanic by no means I am a single mother trying to make do with YouTube videos and just common knowledge so I did hook it up to a computer and I have no codes that it's reading out

If the wiring was chewed up it may have blown one or more fuses. Do you have a test meter and have you checked fuses in both fuseblocks (underhood and under rear seat)

 

[TollKeeper]

When you turn on the key, are you getting all the typical dash lights, and guage sweeps?

I know the mega fuse is a big known problem spot on these trucks, and depending on what you see happening on the guages, that might be a good spot to start, as well as the rest of the fuses in the fuse panel.

 

[Mooseman]

Please use punctuation as it makes reading your posts very difficult.

You say you're no mechanic but what is your experience level? Most people here are not mechanics but experience can range from "I can change a light bulb" to "I can change an engine". Problems related to no crank can get fairly involved in electrical troubleshooting.

This video gives good troubleshooting places to start without fancy scanners.

 

[christo829]

After the fun time I had with rodent chewed wiring, I'd say you probably have other wires that have been damaged besides just the injector harness. If any of the wires to the PCM, fuse block, or through the firewall to the ignition switch have been gnawed, you could have all sorts of odd problems. Mine started with the windshield washers not working when I turned on the wipers. After the critters came back for another round of wire snacks, I could start the truck, but half the instrument panel went out, and I couldn't shift the truck in to gear.

I had no blown fuses. All but one of the chewed wires were part of the serial data bus, so nothing could communicate. That also meant that no codes were showing up.

When you put the key in "Run", do you hear the fuel pump run for about two seconds? As Tollkeeper asked, how does your instrument panel behave when you try to fire the truck up?

When you say it won't fire, does that mean it *does* crank?

How comfortable are you with the use of a multimeter, soldering iron, and crimp tool?

Good Luck!

Chris

 

[Mooseman]

I misread (see what I mean). Thought I read that it wouldn't crank. So it cranks but won't start? Now to find why. Try spraying starting fluid into the intake while cranking. If it starts and runs on the fluid, it's likely a fuel problem. If not, then there's no spark. In either case, it can take quite a bit of troubleshooting, testing and knowledge of electrical and electronic systems to possibly fix. Could also be related to the rodent issues but maybe not. It can happen without chewed wires.

Here's some reading:
Cranks but won't start