2004 Yukon trouble

[Stucky8313]

Hello everyone...
I have a 2004 Yukon that ran hot on my wife 2 months ago. I was able to top off the coolant and oil and she was able to make it home. We let our Yukon sit in the garage for the last two months while pondering what to do with it. (she drove my personal truck while I drove my work truck) Yesterday, I went to move our Yukon and it didn't crank. Battery was dead. Hooked charger up and battery ended up being faulty. Installed new battery and now it will not fire. Starter spins engine freely and it sounds like it wants to start but doesn't. In addition, the gauges do not work and windows do not operate. Brand new battery, vehicles been in garage last two months.... Im at a loss. Please help!! I have checked the fuses in the engine compartment and the fuses in the side of the dash on the drivers side. PLEASE HELP! Thank you in advance!

 

[Fless]

Moved you here to the Engine & Drivetrain section. Is this a Flex Fuel engine? Is the 8th VIN character "Z" or "T"?

When you turn the key "on" (not crank) can you hear the fuel pump run for a second or two? You can "rent" a fuel pressure gauge at your local auto parts store. Or for a quick test you can cycle the key "on" (not crank) and off a couple of times to build fuel pressure, then use a rag to cover the schrader valve on the passenger side fuel rail, and give the valve a little poke to see if fuel comes out. If only a trickle, you're not getting fuel. If you have full fuel pressure it'll spray pretty good, hence the rag.

 

[OR VietVet]

Moved you here to the Engine & Drivetrain section. Is this a Flex Fuel engine? Is the 8th VIN character "Z" or "T"?

When you turn the key "on" (not crank) can you hear the fuel pump run for a second or two? You can "rent" a fuel pressure gauge at your local auto parts store. Or for a quick test you can cycle the key "on" (not crank) and off a couple of times to build fuel pressure, then use a rag to cover the schrader valve on the passenger side fuel rail, and give the valve a little poke to see if fuel comes out. If only a trickle, you're not getting fuel. If you have full fuel pressure it'll spray pretty good, hence the rag.

@Doubeleive pointed out something to me after I had said, start with the basics like spark and fuel. "Gauges not working and windows not operating". After sitting for 2 months, are any wires chewed by critters?

 

[Stucky8313]

@Doubeleive pointed out something to me after I had said, start with the basics like spark and fuel. "Gauges not working and windows not operating". After sitting for 2 months, are any wires chewed by critters?

My Yukon has been garage kept. After it ran hot, I topped off the coolant and oil, it was a little low on oil. Wife said it ran real good on the way home. I tried to get my scanner to read but wouldn't ever connect. Tried the scanner after new battery installed.

 

[Hobert]

New battery fully charges. Battery Cables / connector to battery? Sounds like a low voltage issue

 

[Meathead16]

What caused the inital overheat condition?

 

[gasser]

It's good that you were able to address the dead battery issue and get a new one in place. However, the fact that it's not starting and you're having issues with gauges and windows is definitely perplexing.

Given that the vehicle has been sitting for a couple of months, a few things could be at play here. Sometimes, when a car sits for an extended period, various components can develop issues. Here are a couple of things you might want to consider:

Fuel Quality: Stale or degraded fuel could be affecting the starting process. It might be worth checking the fuel quality and perhaps even adding some fresh fuel to the tank.

Electrical Connections: Since you've already checked fuses, it's a good idea to ensure all electrical connections are secure, especially around the battery, starter, and other relevant components.

Ignition System: The fact that the starter is spinning but the engine isn't firing could indicate an issue with the ignition system. This could involve components like spark plugs, ignition coils, or even the ignition switch itself.

Security System: Sometimes, a security system glitch can prevent a vehicle from starting. Check if there's any anti-theft or immobilizer system that might need resetting.

Computer System: Modern vehicles rely heavily on their computer systems. If there's an issue with the vehicle's main computer (ECU), it could affect various systems, including starting, gauges, and windows.

Given the complexity of the situation, it might be worth considering getting a professional diagnostic done. A mechanic with the right tools and expertise can pinpoint the exact issue and save you time and frustration.

Remember, troubleshooting these kinds of issues can take some time and patience, but with perseverance and the right guidance, you'll likely get your Yukon back up and running. Good luck, and I hope you're able to get to the bottom of this!

 

[rockola1971]

Check your ground wires for corrosion or loose/broken connection. Especially the ground strap from the rear of the engine to the firewall and down on the frame directly underneath drivers door just forward near where the firewall comes down. These grounds are esential to the BCM and can cause the BCM to not put other modules to sleep which draws the battery down to what underneath what is needed to turn the engine over. Check your battery voltage with a voltmeter after fully charged and then the next day go out and measure it again. You should see around 12.6v + on a fully charged battery. Anything 12.5v or less and there is something draining that battery down. I would clean the ground connections real good with a wire brush because they likely need it. Real common on the C and K chassis pickups and SUV's.

 

[Stucky8313]

UPDATE: Removed both battery cables, wire brushed cables and terminals, reinstalled cables and waalaa! The cables look "clean" but must have been something.
Thanks for all the help folks!

 

[Stucky8313]

What caused the inital overheat condition?

The engine slowly loses coolant over time and the engine consumes oil slowly. This Yukon is, was, my wife's vehicle. I very rarely drive and quite frankly, don't give it much of a thought until it's time to change the oil. My lack of attention basically is to blame.