Installing a new 100amp one wire into '69 chevelle with A/C, electric fans, soon to be fuel injection. I've read a dozen posts about how to convert the wires. As a last question, do I need to worry about changing out any fuses, installing higher amp fuses or bigger gauge wire for this thing since it puts out more? Thanks!
Quick Alternator question!
69307/350Chevelle
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Installing a new 100amp one wire into '69 chevelle with A/C, electric fans, soon to be fuel injection. I've read a dozen posts about how to convert the wires. As a last question, do I need to worry about changing out any fuses, installing higher amp fuses or bigger gauge wire for this thing since it puts out more? Thanks!
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The only thing I disagree with in his article is the use of the factory harness from the alternator. A 10 AWG wire can't carry 50A for fans plus the load from the rest of the cars electrical system. I suggest you run an 8 AWG wire (to replace the 10) to where the horn relay is and then hook your fans and EFI via fuses to the horn relay. A good fuse panel is a good iead when you add the additional stuff. It can also be used for the electric fuel pump fuses.
Ron
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ok, well I have a 100 amp internal reg 1 wire alternator I ordered from summit and I don't think its the exact one on this page: http://www.chevelles.com/techref/ftecref14.html. None the less, is this how I am supposed to wire it up? Thanks for all the help guys 
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So...that a yes?
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i agree that from the ALT to the Horn Bus Bar use #8AWG wire.
i would also upgrade to #8AWG from the HornBusBar to the Distribution Block on the passenger side of the radiator support and also use #8AWG from there to the Battery+terminal.
i would insure that you have a good ground from battery to engine block and from engine block to frame and frame to radiator support+body. this will insure that the extra power flows thru the proper places not the (speedo cable or other items that can conduct but are not meant too....):thumbsup:
i think link shows what to do with the wires going to the old regulator assembly and how to hook up the alternator correctly.ok, well I have a 100 amp internal reg 1 wire alternator I ordered from summit and I don't think its the exact one on this page: http://www.chevelles.com/techref/ftecref14.html. None the less, is this how I am supposed to wire it up? Thanks for all the help guys
this link here also has lots of good info/how to/ and why info.
http://www.madelectrical.com/newstuff/
you should have it under control now...:thumbsup:
You may want to check the Mad Electrical site, lot of good info there. There is a good reason to leave the wire from horn relay to junction block and to battery, which should be 14g fusible link, alone. The smaller wire slows the charge rate, and drain rate, on the battery. The slower charge rate, now that you have a larger alt, is better for the battery. The fans and new accessories should run off the alt, not the battery, so a larger wire from alt to horn relay is a good idea. Also 8g from battery to chassis, passenger fender. This is the ground path for the new fans and all other accessories and lights.
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Ok, so when you guys say "distribution block", are you talking about the side of the fuse block thats just below the master cylinder? I can see where that splice is, where it splits off in 4 directions, and I will be changing the wires to 8 gauge.
Good advice from Hank, though I disagree about leaving the fusible link at factory size. When adding load to the electrical system (fans, ignition, stereo, lights) of course the supply side must be upgraded (alternator to horn relay). I feel the fusible link and battery-to-horn-relay wires should go bigger also, so the battery can power the car with its additional load if/when the alternator fails. Without an alternator, the battery would need to power everything through the fusible link. If that link overloads and melts it would disable the entire car.
What is the continuous capacity of a factory 14g fusible link? 30A? Electric radiator fans by themselves would pull that much current.
My recommendation for wiring a 100A alternator is:
alternator to the horn relay with 8g or 6g wire,
horn relay to fuse panel with 14g fusible link and 10g wire,
horn relay to battery junction with 8g,
battery 12g fusible link, and
2g or bigger for the battery ground, very important to remember the ground side.
Clean the ground cable contacts at the engine, frame, and fender and your new 100A alternator should be good.
What is the continuous capacity of a factory 14g fusible link? 30A? Electric radiator fans by themselves would pull that much current.
My recommendation for wiring a 100A alternator is:
alternator to the horn relay with 8g or 6g wire,
horn relay to fuse panel with 14g fusible link and 10g wire,
horn relay to battery junction with 8g,
battery 12g fusible link, and
2g or bigger for the battery ground, very important to remember the ground side.
Clean the ground cable contacts at the engine, frame, and fender and your new 100A alternator should be good.
You need to read the entire article on Chevy main electrical systems to understand what all is going on. The smaller 10g wire and 14g fusible link between the battery and horn relay will suffer from voltage drop under a heavy load. This can occur whan the battery is drained and the alt is trying to recharge it. The voltage drop which results in reduced current flow is a good thing. It reduces the charge rate on the battery, we all know a slow charge rate is better for the battery. The reduced current flow also reduces the load on the alt so it doesn't overheat.
Again, the battery is meant to start the car, after that the alt should carry the load. Should the alt fail the 10g wire will again reduce the current drain on the battery. With a complete alt failure you would know it pretty quickly as the voltage to the electrical system would drop, battery can't maintain the voltage at the horn relay at the proper level. It's unlikely the fusible link would blow as the reduced voltage at the horn relay would reduce current flow to the fans and other accessories. Unlike a fuse it requires pretty much a dead short to blow a fusible link. The can carry an overload for an extended period of time, a fuse blows pretty much instantly.
Anyway that's my thoughts based on different articles I've read. Upgrading the wire and fusible link won't hurt anything in most circumstances, leaving them as is won't either. Don't forget to upgrade the pigtail from negative battery post to passenger fender, that is a must.
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The fusing current of 14 gauge wire is approximately 160 amps. The fusible link is designed to protect the wire it is in series with, not any downstream devices. They should be separately fused. Replacing the charging wire to the battery will have very little effect in case of alternator failure. Most guys will reduce the electrical load to a minimum when this happens, and having a little more wire resistance will actually allow the battery to last longer.
Well said!
The path from the alternator to the fuse block is what generally counts. However, if you expect your fans and your megawatt stereo to work off the battery you need to reassess the use of a 10AWG wire from the battery to the horn relay...
Ron
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Well it's in, it runs, it charges, nothing has exploded Thank you guys for all your help! Now...this coming weekend...engine swap!
Thank you guys for all your help! Now...this coming weekend...engine swap!1 - 15 of 15 Posts
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