[ejw]

I recently realized my disconnect will not shut car off w alternator. I am installing a 4 post switch and cannot find info on Web about how to wire in my alternator (powermaster using stock wiring). How do I wire in the alt.?
The alternator can also be installed as a 1 wire setup. Would it be easier to go w this? If so, can I run wire to remote solenoid on firewall that connects to 2ga positive battery wire going to trunk or do I need to run to disconnect in trunk? Which I guess then I wouldn't need 4 post disconnect.
Thanks.

[Chief of the 60's]

This is what I used - https://www.summitracing.com/parts/prf-50105

I am surprised tech does not require it.

[johnta1]

I am installing a 4 post switch and cannot find info on Web about how to wire in my alternator (powermaster using stock wiring). How do I wire in the alt.?

Should be a few threads here.
Do a search and should find many diagrams and info.

[S/st 54]

Originally Posted by johnta1

Should be a few threads here.
Do a search and should find many diagrams and info.

If someone finds info and diagram could ya post a link?

Since the format change on here I have been unable to do searches

[johnta1]

Try this one:

Battery switch

[S/st 54]

Originally Posted by johnta1

Try this one:

Battery switch

Thanks John!

I got to playin around on the summit link that was provided...Good info too! Also it shows why summit's website is above the rest it provides a link to the manufactures site with instructions.

[Skip Fix]

I posted this similar question awhile back lots of different ways. A couple of friends that worked at parts stores before opening shops tested alternators. They say many that even when field wire was not hooked up had output so it could back feed the harness(it all hooks up together in the main hot feed in the factory harness). So mine has alternator output hooked to battery hot side of switch. Switch on gets output to battery and also harness via switch. Switched disconnect no hot going anywhere out from the battery so should not be able to back feed the ignition and harness. Wired in a separate ANL fuse in line.

[johnta1]

That's the main thing for using an alternator.
The main wire should not be feeding any other circuit in the wiring system.
Go straight to the battery side of the disconnect switch, for the easiest way.
(but the wire will be hot even with switch off)

Use a relay on the alternator wire will eliminate that.
(if wired correctly)

Or as ejw said, he will be using a dtdp switch which will make it simple to use.

Alternator wire to one of the small terminals, the battery cable to one of the big terminals.

Done.

[Skip Fix]

John pull apart a factory wiring-I just did flipping the Camaro's to the correct side for a Pontiac. The main hot wires all are connected including the alternator wires into the harness. Some of the Pontiacs connected one wire at the battery cable at the starter. They can then back feed into the harness and continue to light the engine, why it keeps running off the alternator when you disconnect the battery.

[johnta1]

I guess I should have said no wires from alternator should go to any other circuit except to the battery post.

I know the other wires are connected together later.
Just figured for a race vehicle most don't run a stock setup.

On my dragster I run the 2 small wires right to the alternator output post.
Sometimes I might run the field wire to a switch so I can control when it is charging. Just depends on my mood.

[Skip Fix]

Also depending on the amp rating on the DPDT the smaller terminals may or may not support the load.

Got you on the wiring. I figured since he is using a 3 wire he has some factory wiring like I am going to use/

I found on the Camaro's main feed the factory actually soldered the wires together which many auto wiring folks say should not be done.

[johnta1]

My 70 Bird has a crimp fitting for the original connections.
On that Bird I used the wire to the back connected to the battery side of switch.
(too cheap for dpdt)

[ejw]

My alternator currently has stock wiring harness but can be used as 1 wire. Could I just run as one wire and connect to battery cable junction block at firewall and not have to run standalone wire to trunk. If I do this it should charge battery and shut down w disconnect?
Thanks

[Chief of the 60's]

I never saw a good reason to go 1 wire. If it was such a great idea, GM would have used it to save money. I certainly would not use it with an MSD box due to the fact 1 wire does not charge at low rpm.

[BruceWilkie]

Originally Posted by Chief of the 60's

I never saw a good reason to go 1 wire. If it was such a great idea, GM would have used it to save money. I certainly would not use it with an MSD box due to the fact 1 wire does not charge at low rpm.

Have a true 1 wire 61 amp 10si altenator on a street rod over at the shop. It's self exciting without reving it etc.. Yes, it charges when it needs to, including idle.

Only 1 place you can put a wire on it.

Http://www.Wilsonautoelectric.com
Part# 90-01-3125
Think it came from O'Reilly's or Advanced Auto

[johnta1]

Could I just run as one wire and connect to battery cable junction block at firewall and not have to run standalone wire to trunk. If I do this it should charge battery and shut down w disconnect?

Does the battery junction block have any other circuits connected to it?
If so, it won't work.

Might try the relay idea.

I certainly would not use it with an MSD box due to the fact 1 wire does not charge at low rpm.

It should charge?
The other wire is used to keep the alternator from overcharging basically.
(keeps it charging only when needed basically)

For no longer than the engine is ran, doubt it will overcharge the battery.
(unless still a street car)

I never charge between rounds, usually don't charge anytime.
(depends if I have ran the fan for a long time, like forgot to turn it off )

[R639]

You may have a solution already but here is a description of the problem and a basic method to address it:
The issue is that there are two sources of power i.e. the battery and the alternator. A two post disconnect switch will isolate the battery but not the alternator. Assuming the battery and disconnect switch are in the rear of the car, there is a heavy 2/0 - 4/0 gauge wire running from the battery to the disconnect and from the disconnect to the engine area where the starter and the rest of the electric system connect. Disconnecting the alternator requires a disconnect switch with 2 extra posts. There are two wiring methods to accomplish this.
First way is to remove the main power wire from the alternator and connect (or splice) that wire to a 2 gauge wire that would run back to one of the two extra posts on the disconnect and then run a second 2 gauge wire from the remaining extra post forward to the alternator.
This requires that the 2 extra disconnect posts be rated for the alternator current which can be 100+ amps depending on the alternator used. Many 4 post disconnects have 2 posts rated at 200 amps and the 2 extra posts rated at only 20 amps. A single 2 gauge wire could be used but it requires some possible rewiring of alternator to electric system if the car has existing factory wiring. Just running the 2 wires is simpler.
Second way is to use a relay rated for the alternator current and use the 2 extra disconnect posts to energize the relay. A disconnect with the extra 20 amp posts works fine since the relay coil is usually less than 1 amp. A 12 gauge wire from the relay coil would connect to one of the extra disconnect posts and the other extra post would connect to the battery or the large disconnect post that the battery is connected to. The relay must be rated for continuous operation or it will get very hot after a few minutes and fail (experience speaking). It will also be using a small amount of current for it's coil any the time the disconnect is on so the disconnect should be off when the car is not in use.
For simplicity, I prefer the first option.

[johnta1]

Good post.

[ejw]

Thanks for replies.

[Skip Fix]

You can get by with slightly smaller "marine wire" as it has smaller strand that have more surface are and is "tinned" so less resistance.