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alternator output post to what ?

sweetk30

sweetk30

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whats best to run the alt output post cable to ?

the battery to act as a direct filter for any possible noise or little voltage spikes ?

or

the big junction block i wired the system with ? the battery is on 1 stud . next is starter feed power . the rest will be power points for stuff like msd and other feeds for the rig .

i think its should be direct to battery for best performance but just wanted to make sure . i can lay it out both ways with the length of cable i have to work with .
 
Mine has both. The factory one that goes to junction block/starter wires and a 4ga. I added direct to battery.
 
I don't think it makes any difference really, unless there is an excessive amount of voltage drop in the wiring. And that would be a problem in itself, as there really shouldn't be an excessive amount of resistance in the wiring or terminals to make a difference.
 
cool to the wire block it is then . were doing all the big wires from 2ga or bigger so i dont think there is much drop in flow .
 
What amp alternator are you running, and what is your estimated max electrical load?

I don't mean to take this thread off topic, but I'm a bit confused how GM got away with running, what, 12 or 10 gauge wiring off the alternator even as they were surpassing 110A output in the alternators? I'm assuming much of the increased output has to do with being able to sustain a higher load at idle as opposed to actually needing say, 110A peak, but even then, all information I can find says that at best, the stock wiring is good for 50A, from the alternator wiring I've seen that GM used.

Stock battery/starter wiring is another example, as the battery cables are apparently good for at best half as much as the stock starters draw, but that's also not for prolonged use, unlike an alternator, where I can see 50A+ being a sustained load once we start adding electric fans and other electric accessories that draw more juice.

Maybe I've just not been exposed to enough of the later vehicles to know what OEM has been running for wires since the C/K/R/V's?
 
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In response to the original post, one thing to be careful about is where you connect the alt cable if you are using a battery disconnect switch.
The alternator needs to be connected to the battery side of the switch, or it can cause the truck to continue to run if the switch is opened in an emergency shut down situation.
 
I have the big Blue Sea Systems battery switch/diconnect and I wired the alternator to the common side of that switch. In essence, it's the same concept as putting on the junction block.
 
I think there’s a diagram (Maybe MadElectrical?) and explanation of GM’s electrical design. If I remember the summary, the battery is only used for starting the car and so the 10g charge wire is just for maintaining the battery charge and the alternator sends most of it’s power to a junction block that powers the rest of the vehicles electronics.

I don’t think you need a huge alternator charging wire going straight to the battery unless you have some other big current draw stuff connected directly to the battery as well. (Winch, etc)
 
bp71k5 said:
I think there’s a diagram (Maybe MadElectrical?) and explanation of GM’s electrical design. If I remember the summary, the battery is only used for starting the car and so the 10g charge wire is just for maintaining the battery charge and the alternator sends most of it’s power to a junction block that powers the rest of the vehicles electronics.

I don’t think you need a huge alternator charging wire going straight to the battery unless you have some other big current draw stuff connected directly to the battery as well. (Winch, etc)
Click to expand...
That is correct. I have a 200 amp alt., winch, inverter, fridge, lights.. so I added the 4ga.
 
I have found on my older low mileage chevy trucks that when adding the new addons like fans etc the fuse block is not a good place to start. probably most everybody adds the relay feed straight from the battery with the trigger from the starter switch so that is where I would want the bigger alt to feed at the battery. My older stuff starts to have problems at the heater fan blower switch first when idling with the ac on high so I looked at the wiring diag and added a new relay to feed that circuit from the battery to take the load off of the starter sw circuit. Addon to me means more relays and fuses for the older trucks or a complete rewire to a newer fuse panel with more high amp relays and fuses. I would just feed the battery from the alt to keep it simple except that if a disconnect is used needs to be bigger to support the added amps.
 
I have a summit one wire alternator and it just seemed like the best scenario to just hook it directly to the battery. But you have a junction block that would work just as well but may take some of the Amps that would normally go through the battery first before being used by the rest of the electrical system. The output amps of the alt are going to need to overpower the draw in any case either way. So it might not make as much a difference. As long as you are on the battery side of your battery cutoff it should run just like it is wired directly to the battery anyway. It’s a mess having multiple wires going directly into the battery terminal imo. I only have the two and added a fuse panel and wired everything else off of that instead of battery.
 
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