2007 Sierra 1500 - turn signal relay chatter (cut wire)

[Benz0]

Long time reader first time poster...Son just installed his sound system and amp for his first truck with some friends on the grounds he didn't want to pay the install fee.

 

They managed to blow the starter fuse and console light fuse in the process. He also stated that the left turn signal would flash quickly which I've known to be relay chatter in the past on other vehicles which the computer says it's a blown bulb in one of the sockets. He replaced ALL of the left marker and signal lights and still has the chatter. Well, turns out they routed the power wire for the AMP through the big rubber grommet for the wiring harness through the firewall and apparently cut a wire or more when making a hole for the power wire. Anyone ever replace this harness before or try to splice in a wire jumper???

 

If anyone has a schematic I can look at would be great - I'm an ex- US Navy Aircraft electrician so I can read them

 

Thanks!

Benz0