[AKLankford]

So without going too much into the details (Stupidity on my part) my 08 Silverado 5.3 had a dead battery after being away on vacation, went to jump start it and accidentally switched the cables around on the running vehicle. The cables were hooked up 5 maybe 10 seconds before I noticed my mistake. Terminals smoked a little but nothing major visually. I hooked the cables back up normal, let it sit for about 10 minutes to get a charge and had absolutely nothing from the battery. Today I went and bought a new battery (it needed a new one anyway) hooked it up and still had absolutely nothing.

I've ran through the obvious fuses and none were burnt out. What I'm asking is what do I need to look for? Is there something obvious I missed? Electrical isn't really my strong point. I'm really hoping the ecu isn't fried like the horror stories I've been reading online. Thanks for any input guys and if you need to know any more details let me know.

PS: Feel free to call me dumb :roll:

 

[judsonlimited]

most likely have a fried ECU.

 

[AKLankford]

Aw man don't kill my hopes yet haha :shock:

 

[CarMech97]

So when you turn the truck on, nothing electrical will work?
If so, it sounds like a main fusible link has burnt out. You need to find it and replace it.
On my '92 Sierra, there is a wire that runs from the positive battery terminal to the main body feed on the firewall. Along the wire, in between those two points, lies the fusible link.
On your '08, it is likely different though, so I can't tell you where it is. But this hopefully gives you an idea of what you need to do.

CarMech97

 

[apcnc]

Is anything coming on at all? Lights? Do you have power to the terminals at the fuse block. Was the switch or anything on when this happened? May have burned a relay from the flyback. Hopefully the input to the ECM is rectified or has polarity protection.

 

[CarMech97]

Ah, here ya go. You have something called Mega fuses.
Did you check those??
http://www.revbase.com/BBBMotor/Wd/Down ... ?id=153880

 

[apcnc]

That fuse is on the battery cable. I was assuming that was one of the relevant fuses checked.

 

[AKLankford]

So when you turn the truck on, nothing electrical will work?
If so, it sounds like a main fusible link has burnt out. You need to find it and replace it.
On my '92 Sierra, there is a wire that runs from the positive battery terminal to the main body feed on the firewall. Along the wire, in between those two points, lies the fusible link.
On your '08, it is likely different though, so I can't tell you where it is. But this hopefully gives you an idea of what you need to do.

CarMech97

Thanks for the input man. I'll check that, like I said electrical isn't my strong point and I automatically bypassed that and went to the fuse box.

 

[GMT604]

Battery installed backwards, please help

 

[AKLankford]

Tested and replaced the fusible link. Truck fired right up! Thanks everyone for the input, you guys saved me the headaches. Gonna try to keep my stupidity levels in check...

 

[apcnc]

Eggselent! That was fast!

 

[judsonlimited]

Tested and replaced the fusible link. Truck fired right up! Thanks everyone for the input, you guys saved me the headaches. Gonna try to keep my stupidity levels in check...

Red = +
Black = -


Sent from my iPhone using Tapatalk

 

[Gozzie]

Count your blessings that all that blew was a fuse. It could have been very bad with the electronics nowadays.
Hope everyone reads your posts. Tis the season for jumping.

 

[AKLankford]

Eggselent! That was fast!

It's amazing how fast you can work at -10F

 

[jeverts]

Happened to a buddy of mine...he was sure he was going to have to fork out thousands in electrical work. Turned out to the the mega fuse. 5 dollars and 5 minutes later, truck was as good as new. Awesome security measure by GM. Glad it worked out for you too!