1976 C-20 upgrading a/c and alternator

[Mr. Goodtool]

Hello group!
Here's my questions.... Can I re-purpose the factory a/c fan's high speed "orange" wire's size to increase the wire size to use as a new charge wire for the new "powermaster" 140amp alternator? as scrap, after demo'ing out the old wires, I need to know if it's gauge is big enough. It looks pretty big in diameter, but does anyone have a clue what gauge it is? Powermaster recommends a #6 wire, for under 4' long applications. Is the high speed wire to the old a/c fan, #6 gauge?
I will take out the 30amp fuse connector/holder off of the old wire length, and re-purpose the longer portion that's left, as a wire to use on the #47294 Powermaster alternator. It will go to the positive terminal block on the firewall....right? The alternator will be used as a three wire system. I live in Las Vegas, Nv. and because of the summer heat, my mechanic friends tell me I should run an auxiliary fan in front of the new a/c system's condenser, as well as the regular engine's fan. The aftermarket system is from "vintage air", but the aux fan is not supplied with the kit....."73-84 with factory a/c". My second question is, is an aux. fan really necessary??
Thanks to all in advance!
Regards!!

 

[HotRodPC]

6 Gauge is pretty damn heavy wire. I'd imagine the AC wire is probably a 10 gauge. I think you can get 8 Gauge which should be plenty if kept under 4 feet, and I wouldn't be afraid to go 6 foot if needed. Overkill is always better but a roll of 8gu about 8 or 10 feel long should be about $8 at your local discount auto parts. I'd go with that in RED.

Aux fan probably isn't 100% needed, but sure nice to have on a hot day if you're towing something or sitting in stop and go traffic. Is it a factory Aux fan? It's probably a featured option on your truck if it's OEM. Just unplug it and watch your temp gauge. If it starts to run pretty warm, then yep, probably need it.

 

[Mr. Goodtool]

Hello HotRodPC! the aux fan is most likely going to be aftermarket. My close friend of a few decades, Is the owner/operator of "Sin City Hotrods" here in Las Vegas. He's giving me several parts and pieces, to complete the installation. I'm retired, and am a survivor of three summers here, but with these upgrades, and new a/c kit...no more!
That's why I wanted to know what gauge the orange wire was. The higher amp alternator is needed for the a/c and the aux fan. I have been all over the internet to find a gauge chart for sizing that wire, with no luck. thanks for your reply!

 

[Craig 85]

I can say for sure '85 and to '95 454 trucks/Suburbans with A/C and auto trans come with and aux fan stock that is mounted on the passenger side of the truck IFO the radiator. It's about an 11 1/2" fan with a mesh cage over it. I've had 6 trucks within this year span and all had them.

 

[HotRodPC]

I can say for sure '85 and to '95 454 trucks/Suburbans with A/C and auto trans come with and aux fan stock that is mounted on the passenger side of the truck IFO the radiator. It's about an 11 1/2" fan with a mesh cage over it. I've had 6 trucks within this year span and all had them.

Yep, that's why I asked if it was OEM or aftermarket. My 86 C20 OEM 454 had it, and so did my 88 Burb OEM 454. I know one of bucket's Burb that was a 454 had it too.

 

[74 Shortbed]

My 86 C30 dually had the AUX fan on it..

 

[Mr. Goodtool]

Hi; thanks for the replies! My c-20 is a 1975, and the original a/c condenser was demo'ed out long ago. I don't know if 75's ever had an aux fan. The truck originally had a 454, but now sports a hi-perf. small block 400, punched twenty, with aluminum 68cc heads, and a comp cams valve train, including roller rockers. Road jerks think i'm a push-over, till they eat my dust!

 

[HotRodPC]

Sounds like it oughta have some real good compression and should run real nice on some good gas.

 

[Mr. Goodtool]

Soooo, the wire that powers the fan's "high speed" is #10 gauge. I have located wire large enough to keep the alternator happy...#6. The factory "charge wire" definitely emanates from the firewall terminal block. That same wire goes to the starter, but the wire is tee'ed off inside the wire loom and is not a separate connection. The existing charge wire to the alternator will not be cut, just folded back into the wire loom sheathing, on top of the engine. All this, to relocate the alternator to the drivers side, for the a/c AND....YAY! the two wire connector reach'es the new location with the alternator "clocked" at 12 o-clock. The accessory bracket kit is by "JL Fabrication" #350al-pc 350-cl-pc...this kit "high mounts" the a/c-alt, locations. If someone wants me to keep a running timeline on the install, I'll try, especially when serious problems arise.