Different wire gauge sizes - ok ??

adamsnez2

Seaman Apprentice
Joined
Apr 15, 2010
Messages
47
Hey iBoats :)
Here's my question, my motor is an electric start 1965 Evinrude.
It has a wire harness (obviousely) coming off it, inside there are 6 smaller wires, the and 4AWG positive and negative wires. (8wires total, although 2 wires are cut and covered inside the motor cowling and connected to nothing).

On the other end of the harness, is a plastic clip (quick connect, that connects into a junction box attached to transom -- which leads to electric start from boat key on dash, obviousely again haha)

Here's my question:
I can't tell the original gauge size. It appears to be 12 or 14, for sure.. Either Or.. I bought 14AWG to replace these wires, all different colors.

Here's the question, IF the 6 wires are 12AWG, and I replace with 14, is this still safe? I know you should replace with the same gauge when doing so, I just can't tell 100% for sure... So is downsizing one gauge size alright to do? Especially for a boat motor, not sure how much amperage these things pull to their respective parts of the motor.

Thoughts? Insights? Green lights to go ahead? Thanks guys
 

Juniinc

Petty Officer 1st Class
Joined
Jan 16, 2010
Messages
221
Re: Different wire gauge sizes - ok ??

U are most likely running a 20AMP fuse,,,
I would personally do it with 12Ga, I'm sure others will say 14 is fine,,,
wire stripper will tell pretty close, what they were.
Good luck.
 

ajgraz

Lieutenant Commander
Joined
Mar 1, 2010
Messages
1,858
Re: Different wire gauge sizes - ok ??

Does the control box and harness look like this?

REMCONTBOX.jpg
 

adamsnez2

Seaman Apprentice
Joined
Apr 15, 2010
Messages
47
Re: Different wire gauge sizes - ok ??

U are most likely running majority of 20AMP fuse,,,
I would personally do it with 12Ga, I'm sure others will say 14 is fine,,,
wire stripper will tell pretty close, what they were.
Good luck.
haven't been to boat in a while (it's at the cabin, motor is at home).
But i recall there being only one inline fuse (under the dash, not sure the amperage)
 

adamsnez2

Seaman Apprentice
Joined
Apr 15, 2010
Messages
47
Re: Different wire gauge sizes - ok ??

To the pic above; no.

It goes Harness from motor ---> plugs into other harness in a junction box ---> leads back to front of boat.

inside that box, i have to connect the + 4awg to a wingnut post, same with the 4awg ground from motor.

very basic. no tach, no choke, no ign kill...

When i say junction box, i moreso mean a metal box mounted on transom where all the wires come together and either, connect to a wingnut post, or connect clips together
 

adamsnez2

Seaman Apprentice
Joined
Apr 15, 2010
Messages
47
Re: Different wire gauge sizes - ok ??

it's a RECTANGULAR plug btw, not the circle style.

I did some reading, and PaulMoir said the two black wires are 18AWG (they don't look that small at all!!).
Does anyone know the correct AWG size for these wires?

1965 ski-twin 33hp is the motor.

Still wondering if 14AWG is acceptable (EVEN IF ORIGINAL ONESS WERE IN FACT, Smaller!) for all the smaller gauge wires (and still using 4awg for batt start and ground)
 

adamsnez2

Seaman Apprentice
Joined
Apr 15, 2010
Messages
47
Re: Different wire gauge sizes - ok ??

I have found this out;

The wiring harness has 2 black wires from the coils to kill the motor,
a white wire that is for the saftey cut-out switch
red wire for the power choke.

These are the four wires I'm using (2 went nowhere, cutting them out). The 2 magneto wires, choke, and safety cut-out, what AWG is recommended??

(ps; what the HECK is safety cut out wire even for?)

Thanks.... Looking to wire this up this week. Anyone? Please :(
 

ajgraz

Lieutenant Commander
Joined
Mar 1, 2010
Messages
1,858
Re: Different wire gauge sizes - ok ??

You can't go wrong going to larger wire than what was there originally.
 

adamsnez2

Seaman Apprentice
Joined
Apr 15, 2010
Messages
47
Re: Different wire gauge sizes - ok ??

that i know yes, i just can't tell if it's actually 12 or 14 (and i have 14 already cut).

I'm just wondering, cuz PaulMoir said magneto wires for this motor were *18awg* DEFINITELY don;t look it...

Just wondering if you guys who have done rewiring before have seen / can tell me if 14 is sufficient for magneto, elec choke, and safety cut-out (and what that safety cut out even does still lol)
 

ajgraz

Lieutenant Commander
Joined
Mar 1, 2010
Messages
1,858
Re: Different wire gauge sizes - ok ??

Electric choke probably pulls 3 to 5 amps. Safety cut-out just grounds out the switchbox (or coil(s), does that motor even have a switchbox?) to interrupt spark and shut down, say at key-off. Magneto likely powers nothing more than a couple of light bulbs (nav lights), yes? If so, maybe 2 or 4 amps. 14 AWG should be more than fine for even a 20-foot run for those uses.
 
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