What Wiring Gauge For Alternator / Starter?

[Quarterwave]

Hi everyone,

I'm replacing some of the wiring on my engine build (5.7 GM truck engine that has been converted for marine use) and need some help with the wiring from the starter to the alternator.

What gauge wiring should I use?

What type of connectors should I use?

I'm working through an older harness from my previous Mercruiser 5.0 and will be soldering and then heat-shrinking any splices that may be needed (some connectors are corroded), but knowing which wiring to use would be a great help.

NOTE - many of the connectors are not in great condition, so are there any "kits" that I can buy that will give me a bunch of wiring, connectors, clips etc....?

Thanks!

 

[Bondo]

Ayuh,... The wire from the Alt. to the starter is usually 8 or maybe 10 ga......

From the battery to the starter, I use #0 ga. or #00 ga,......

I buy my wirin' kits from my local Napa,.....
Donno of any for "Marine", nor "Merc",.....

 

[fishrdan]

Are you using the truck's starter and alternator? If so, you can't do that, they are not spark suppressed, bad things can happen - boat goes BOOM!

Use the starter and alt of the old engine, or marine rated replacements for the original starter and alt.

You post says solder and heatshrink, but you must crimp first, need the mechanical connection before soldering. If you have good crimpers, you don't need to solder. That said, I crimp, solder and heatshrink.

Go to genuinedealz.com to get your wiring, crimps, etc. They sell high quality "marine" wire and supplies, free shipping, only takes 2-3 days to get it.

 

[Scott Danforth]

what size alternator?

I went from a 55 amp to a 105 amp. so my wire jumped from a #6 gauge to a #4 gauge

I have an assortment of tinned marine cable and wire. for what I dont have in stock, I order and wait a few days for the stuff to show up.

as for the ring terminals on the battery and charge cable, you get them for the size of cable and the stud needed.

 

[Quarterwave]

Thanks everyone.

Fishrdan - yes, the starter and alternator are new, marine-grade.

 

[Quarterwave]

Hi Scott,

The alternator is a standard, 55 amp alternator.

 

[Bondo]

Hi Scott,

The alternator is a standard, 55 amp alternator.

Ayuh,.... So go with # 6 ga.,.....

I guess I was alittle light in wire gage in my post above,....

 

[fishrdan]

Blue Seas DC wire calculator is handy for figuring out what size of wire is needed.

55 amps with 10' of wire (I went way looong) only needs 8ga wire. Won't hurt to use 6ga though.

 

[Quarterwave]

Perfect, thanks everyone!