EFI Rewiring: Bad vs Good Idea

Decided to overhaul my EFI wiring this week since it's getting on my nerves. Half of my injectors stopped working a few days ago, the fuel pump wires were smoking, the cable terminal block were melting and tonnes of other stuff made me sick and went to rip and re-did the whole thing.

Using terminal strips as wire junction, i gotta admit, was a bad move. Actually, it's not really that bad idea. DIYAutoTune, Megasquirt's official retailer, whose idea i copied, uses similar stuff on their MS Relay Board kit. It's actually nice that you can undo sensor wires individually with ease. The problem relies on your placement of the terminal strips under the hood. Here's what a bad location could do to your strips.

As you can see, those strips are melting all over the place. What's wrong? Here's what's wrong:

When i first placed the terminal strips there, i was still running NA. There's was no turbo to cause the extra heat to melt the strips. So, if you decide to go with terminal strips, make sure you plan ahead and place them away from exhaust.

I decided to get rid of those strips and use connectors instead. I can't find one rated for automotive use being sold near to where i live so i had to compromise with DB25 computer connector. I made sure it's placed far enough from the turbo. Let's see if it can withstand under-hood temperatures.

I also made sure correct wire thickness are used. When it comes to wire thickness, you can never go too big. Your limit is only space availability. No one would blame you for using 14 AWG on MAP sensor harness but that's overkill. On the other hand, 22 AWG on fuel pump or injector wiring? Be prepared for catastrophic failure. I'm going slightly overkill on the main power wire as it will supply all the EFI components, fuel pumps, injectors and ECU included. I even used a battery cut off switch so my EFI system is now separated from the ignition key turn. Here's the cut off switch, not yet mounted properly.