66 c10 Ls harness routing
 

I am trying to figure out the best way to get my ls swap harness from the cab to the engine bay to look clean. I want to see some ideas on if it’s best to mount Ecm under the dash and pass through the firewall. Or if it’s easier to put it under the seat and run under the cab. I don’t really want to cut my new Nelson performance harness to extend it if I don’t have to.

Re: 66 c10 Ls harness routing
 

Did you get them to extend it from stock length?

Re: 66 c10 Ls harness routing
 

Im running mine down the back of the motor and up through the floor. The main determining factor, like Clyde has mentioned, will be length.

I was planning on going through the firewall on mine, but I had too much length and would have had a coiled mess. Running up through the floor uses up that length and keeps the hole out of sight.

Re: 66 c10 Ls harness routing
 

Any pictures of where to locate the hole and how it was ran?

Re: 66 c10 Ls harness routing
 

Any pictures of where to locate the hole and how it was ran?

Re: 66 c10 Ls harness routing
 

I haven't ran my wiring yet, just mocked up. I picked a place on the floor that I thought would be clear of my seat mounts and leave room to mount the ecm on a flat surface while being under my seats out of view with enough wire to comfortably reach everything. The other thing to consider if you run it this way are things like exhaust, the driveshaft, and places to secure the harness in order to keep it away from those items.