New Alt Wiring

[jamieg285]

I am going to fit a new upgraded alternator to my 79 Camaro soon, and want to upgrade/replace the old/ugly wiring that's attached to it at the same time.

Looking at the wiring guide I can see that there are 3 wires coming out of it.

The brown goes to the instruments, but the 2 reds join together, before being connected to the starter and the firewall connector (both with fusibile links)

I want to strip out and replace all of this. I figure I can run the 2 red wires from the alt straight to the starter, and then a wire from the starter to the firewall connector.

The fusible link on the firewall will obviously protect the whole cars system, so this has to stay/be replaced with a fuse(Prefered option). What size fuse is required here?

Does there need to be a fuse between the alt and the starter (on either or both wires), and if so what size?

[Madspeed]

To Feed the whole car? a big one
As much as your alternator can put out
you can start with 50 amp Id say no more than 100

[MickMc]

Jamie
call or log on to Madelectrical.com. I could give you all sorts of advice but Mark @ MadElectrical.com has the facts and best of all Pictures and diagrams.
Mick Mc

[johnejohn]

Mick Mc, thanks for the MadElectrical link it's really helping out my learning curve.

[Texas Hotrod]

Single wire alternators work for me.

[PT Goat]

Jamie
call or log on to Madelectrical.com. I could give you all sorts of advice but Mark @ MadElectrical.com has the facts and best of all Pictures and diagrams.
Mick Mc

Definitely give MAD a call - I just wanted wiring for a better alternator and ended up upgrading most of my electrical system. And he'll talk to you about you're setup as long as you're willing to stay on the phone. Excellent company.

[BonzoHansen]

The fusible link on the firewall will obviously protect the whole cars system, so this has to stay/be replaced with a fuse(Prefered option). What size fuse is required here?
Don’t fear the link! Links handle temporary spikes far better than fuses and they are more reliable (corrosion issues, fuse getting loose, etc.). If you are popping links, you have bigger issues than how hard it is to change it.

[Johnny Blaze]

I am working on the same thing. Those links helped out a lot, but I still have a question.

The brown wire, which is used for the indicator light, can it just be left unused, or does it need to go to a switched hot source?

[gmachinz]

That brown wire is yoru remote voltage sensing wire. It basically tells your gauge how much voltage demand is being require from your alternator, and the regulator has to "read" the draw in order to put out enough amperage. If you read on Mark's site, he explains how remote voltage sensing works and why it is more reliable than a 1-wire design. You can call Mark and he can explain further or if you want, you can give us a call at 515-979-8602 and I can help you draw out what you need to do. It's really easy to do once you understand the basic theory behind the system. -Jabin