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**dmjlambert** · 05-08-2018, 09:09 AM

The red and brown wires that used to go to the regulator but will now go to the plug on the alternator do not need to be 12 gauge, they can be something smaller such as 16 gauge. The red one senses the voltage level at your main junction some feet from the alternator, and the brown one senses whether the ignition switch is on and in some trucks grounds a generator light on the dash. So those are not heavy current applications.

Regarding The wire looks pretty heavy - probably 10 gauge. So I should split this and add 6-9 inches of 16 gauge with a fusible link? This sounds like it would easily blow, but I will take your word on it. The fusible link wire is available in 16 gauge, which is 2 sizes smaller than the 12 gauge you have running to the alternator, and has a flame-proof insulation. It is supposed to burn up if you have a severe short somewhere, instead of allowing your truck wiring to burn up. It's a sacrificial wire that acts as a kind of fuse. It's available at any car parts store, and I've only seen it in grey color lately.

05-08-2018, 09:09 AM	#42
dmjlambert Senior Member Join Date: Apr 2016 Location: Cypress, TX Posts: 3,573	Re: Alternator question The red and brown wires that used to go to the regulator but will now go to the plug on the alternator do not need to be 12 gauge, they can be something smaller such as 16 gauge. The red one senses the voltage level at your main junction some feet from the alternator, and the brown one senses whether the ignition switch is on and in some trucks grounds a generator light on the dash. So those are not heavy current applications. Regarding The wire looks pretty heavy - probably 10 gauge. So I should split this and add 6-9 inches of 16 gauge with a fusible link? This sounds like it would easily blow, but I will take your word on it. The fusible link wire is available in 16 gauge, which is 2 sizes smaller than the 12 gauge you have running to the alternator, and has a flame-proof insulation. It is supposed to burn up if you have a severe short somewhere, instead of allowing your truck wiring to burn up. It's a sacrificial wire that acts as a kind of fuse. It's available at any car parts store, and I've only seen it in grey color lately.