t_thall

iTrader: (4)

Just finished installing my new engine and 4l80e this weekend, did the tranny wiring and hooked up the battery. When i turn the key on everything lights up and the security light comes on. It will not turn over. After this the dash and marker lights stay on along with the security light and the only way to take them off is to disconnect the battery. Once i turn the key on again it all happens again. My hp-tuners won't connect to the truck. Our shop's Snap-On Solus scan tool won't connect. The procedure in our manual to reset the security light does not work. Also another weird thing - i've had a trickle charger on while i was trying to figure it out and whenever i remove it the door chimes go off for a while. Anyone have any idea of where to look? It looks like all grounds are hooked up and everything is plugged in properly. I though it maybe cause the old tune is still in there but i can't get in to change it!

GMCtrk

iTrader: (27)

Re-do all the grounds. When I got the LQ9 in it would not turn over. All kinds of weird **** was happening. Both of my turn signals would light up on the dash, the tow/haul light would come on, my speakers popped when I locked the doors, etc. I never in my wildest dreams thought a bad ground could cause all this. I thought I had friend something electronic but all fuses were good. It was the bad ground from the battery to the block.

thunder550

iTrader: (70)

+1 for double-checking all your grounds. There should be three ground wires on the upper back of the block and two on the lower driver's side.

eallanboggs

iTrader: (1)

Once you check the ground straps try to connect. Check the fuse for the DLC. It's the same one for the cig liter. If it's blown you won't be able to connect. Did you change any modules? PCM, BCM, etc.?

viciousknid

iTrader: (8)

Stupid question but are you using your key fob to lock/unlock the doors to reset the security light or are you doing it another way?
Just throwing it out there.

This problem comes up a lot after a swap and it's usually something simple that takes forever to find. If i get bored i'll do a search cuz i know there's a few threads from people who had the same problem, just don't remember the different solutions.

t_thall

iTrader: (4)

didn't change any modules

t_thall

iTrader: (4)

In our shops manual it says it is a thirty minute process to reset the light, unless you have a tech II.

viciousknid

iTrader: (8)

As mentioned. for the HPT and Scan tool check the Cig Lighter fuse under the hood. I spent hours trying to get EFILive to connect and couldn't because that fews blew. Hopefully that'll at least let you take a look around.
I dunno if shutting the VATs off would help you or not.

t_thall

iTrader: (4)

I figured it out! I had tightened one of the grounds on the back of the engine with an impact and a long extension and never looked at it after it was tight, i guess it must of spun around and snapped the eyelet off, so you guys were right about the grounds - thanks!!

thunder550

iTrader: (70)

Sweet! Glad to hear you figured it out