Upgrading wiring for EFI

Santa bought me a Holley Sniper EFI for Christmas. To prepare for it, I'm upgrading the wiring. Tell me what you think. I think I'm over thinking. No, I know I'm over thinking it!

Here's what I'm doing:

• Moved the coil to the firewall, running 12 volts to it via a harness with a relay with power ran off the starter relay that I can remove later. I need to run a relay for the EFI system, so adding a pig tail for a second relay is no big deal.
• Completely removed old ignition system from engine harness.
• Removed the 12awg alternator wire from the harness
• By-passed ammeter. I plan to create a pig tail to connect the red and black with an extra plug for the power windows. I would like to convert the ammeter gauge to factory looking volt meter. Any links?
• Running a red 4awg from the alternator to a circuit breaker then to a capacitor then to a fused distribution block (FDB) with 2x 4awg inputs and 2x 4awg / 2x 8awg outs.
• Running a black 4awg from the alternator case to a stainless bolt on the right side frame rail.
• Running a red 4awg to the starter from the battery
• Running a red 4awg to from the FDB the starter relay
• Ran new grounds for the turn signals and parking lights.
  
• New eBay headlight harness because I'm measuring 2+ ohm through the wires. That's just 9v to the headlights! The harness came a parts car that sat outside for 15+ years exposed to the weather. The wire must be real crusty in there.
• Running 8awg from the FDB to a relay box.
  
• The relay box with hold fuses and relay for the headlights and fans. I plan to upgrade to 55w/60w Hella lights and 2x 300 watts fans. Also planning to add an oil and power steering fluid coolers with their own fans. All will be power off this box feed via a 8awg red cable off the FDB. It will good for 100 amps and 1200 watts
• Holley recommend running the EFI and CD directly off the battery, so that is what they get.
• Wrapping everything in fabric tape.
• And an OEM style battery hold down.

Power system design:

Read post number 6 click expand to expand the post.. Really good writeup on the ammeter to voltmeter conversion.
https://www.forbbodiesonly.com/moparforum/threads/amp-meter-to-volt-meter-conversion.40423/

bigger alternator?

Don selleck said:

bigger alternator?

Click to expand...

Yes sir!

https://www.summitracing.com/parts/pwm-8-58539/make/dodge

Black of course!! But after Santa pays off the EFI or the old ways breaks. What ever comes first.

i upgraded mine too fuel injection guy said they were finacie about receiving 12v i got the 3x2 fitech set up

Souping up the electrical system is just part of hot rodding!
Mike

Don selleck said:

i upgraded mine too fuel injection guy said they were finacie about receiving 12v i got the 3x2 fitech set up

Click to expand...

The EFI computer don't care for the very dirty power systems found in old cars. A short list of design issues include no caps to drain AC currents, most grounds are laughable, just about every wire is undersized, poorly designed connectors, coils attached directly to the mains, ammeters, and the list goes on. And if the design isn't bad enough, throw in 45+ year old wires exposed to the elements for 20+ years and you got one huge mess.

Holley recommends attaching the EFI directly to a side post battery, using the top post for everything else, and using a relay to isolate the ignition circuit. The battery acts like a buffer against all the noise and chaos going on in the old car.

The alternator question got me thinking that maybe I should go with 2 awg cabling instead of 4 awg on the charging side, it would be $30 more.