Need help with electrical issue!!!

[Ed Ipema]

I'm new to this forum, just recently picked up a 2005 gmc yukon with the 5.3l v8. Lady i got it from parked it about 3 years ago because she was having some electrical issues with it. So as of right now the problem I'm having is when I hook up the battery (which is brand new) the truck automatically wants to start without the key in the ignition and also is leaking gas everywhere. I figured out the fuel problem after I dropped the tank and the fuel pump is completely rusted and broken so I know I need a new one of those. But as for when I hook up the battery and the truck wants to start on its' own, I have no idea what it could be. Any help from you guys would be great. Thanks again.

 

[Tonyrodz]

I'm new to this forum, just recently picked up a 2005 gmc yukon with the 5.3l v8. Lady i got it from parked it about 3 years ago because she was having some electrical issues with it. So as of right now the problem I'm having is when I hook up the battery (which is brand new) the truck automatically wants to start without the key in the ignition and also is leaking gas everywhere. I figured out the fuel problem after I dropped the tank and the fuel pump is completely rusted and broken so I know I need a new one of those. But as for when I hook up the battery and the truck wants to start on its' own, I have no idea what it could be. Any help from you guys would be great. Thanks again.

I wonder if maybe it has something to do with the starter. A short to it.

 

[Ed Ipema]

I wonder if maybe it has something to do with the starter. A short to it.

I am gonna check that when i get a chance. Does it make sense that the fuel pump is running automatically when the ground is put to the battery with no key in ignition tho?

 

[SunlitComet]

If your starter actually engages the engine just by hooking up the battery then try it with starter removed snd try again. If it stays off afterwards then your relay contacts are likely shorted closed if the key is out or something is really screwd up with your ignition switch perhaps. The fuel pump relay is usually controlled by the pcm. So if the pcm is fine one might think there might be something goofy inside the relay box where the wires terminate such as corrosion. Or something chewing on your wires.

 

[Brother Bluto]

Both the fuel pump and starter are on different circuits. Those two circuits intersect at the ignition switch. Check there first

 

[iamdub]

Both the fuel pump and starter are on different circuits. Those two circuits intersect at the ignition switch. Check there first

This. You could just reach under the dash and unplug the wire harness going to the ignition switch, then reconnect the battery. If it doesn't try to come on, replace the ignition switch.

 

[HiHoeSilver]

Both the fuel pump and starter are on different circuits. Those two circuits intersect at the ignition switch. Check there first

This. You could just reach under the dash and unplug the wire harness going to the ignition switch, then reconnect the battery. If it doesn't try to come on, replace the ignition switch.

X3