After cab off electrical gremlin, I am stumped.

I cracked a piston a month ago, cab was pulled and engine, tranny and transfer case were put on the floor. I built the engine and had a good buddy help me get the truck running. It gave us headaches but finally got it running. Skip ahead to prep for the pull, I hooked up the safety kill and went to test it. Doesnt work.
I am using a trailer break away to make a ground contact that switches a relay disconnecting the ignition wire.
Now for the gremlin, We started tracing all the feeds and found that the wire that ford supplies in cab, 12v supply not switched is now 12v supply switched. What I am having a hard time figuring out is why, I cannot find anything that I missed at assembly. The wire in qestion is the one that H&S wants to tap into to supply the mini maxx with voltage on the obd connectors switch.

I did some more digging. I believe the wire I am dealing with is CBP44, it is a violet color with no trace. The body builder book that i got my hands on does not tell me much other than it is constant battery supply.

it is not constant, it is switched. which is why it's used to supply power to the tuner. otherwise the tuner would be on 24/7

drunk on diesel said:

it is not constant, it is switched. which is why it's used to supply power to the tuner. otherwise the tuner would be on 24/7

Click to expand...

That is what I originally thought. But before we had the cab up it was constant power. It did not matter which way the key was positioned, which is why I am confused. Any matter I will change my wiring, just this going from one way to another has me puzzled. may just get my hands on a schematic to find out.

that is very strange!