see the ELD Bypass thread and you'll understand why you see voltage drop.

 

I had to look into ELDs when I got a CEL for a low eld circuit at one point. That was fixed my securing the wire connections more. I would like to read more.

Where is it?

And whats your opinion on upgrades in the electrical system for more performance tuning? Theres not much to be found on it. Or is it basically making sure the circuits are as thorough as possible?