Alternator question...

[hoodride]

I traced an electrical drain down to my alternator the other day and also found a wire just dangling (don't know how I missed that) I've read through quite a bit from what the search brings up but didn't find what I need. It's a 2-wire alternator (a 63 amp I think). The wire I'm holding is the one on the right, and the left wire goes to the back of the alt. (pictured) and then on the the battery.

Where does this go?

 

[hoodride]

Ok, correct me if I'm wrong, but the wire I am holding (the one on the right) is terminal one, which should go to some sort of resistor (do we have a batt. light in first gen blazers?) and then on to the battery. The left is terminal two, and this goes straight to the battery, as well as the battery terminal on the rear of the alternator. Would I fry anything if I just hook all three of these up straight to the battery?

 

[miniwally]

I would guess that the wire your holding needs to be keyed power.

I think???

You need battery voltage to tell the alternator to charge (wire thats hooked up) and the keyed power to tell it the vehicle is running and it can charge (wire thats in your hand).

There are others that are way more into the electrical side of things than I.

 

[bp71k5]

I'd need to look for my wiring diagram, but the big lug on the back of the alternator marked "Bat" goes directly to the battery. The only ground wire on there is the threaded hole in the back of the alternator.

The two plug wires are:
1. Voltage sensor (goes to your main 12V+ distribution block or to the battery) (probably wire not in your hand)
2. Ignition+ (switched ignition source when engine is running) (probably the wire in your hand)

I'd have to go check which is which and maybe post a picture. You should find out for sure if it's the 12SI or the 10SI.

Edit: It looks like someone converted it to a "one-wire-esque" style alternator. The big red lug should not be hooked up to either plug wire. It should go separately to the battery or a juntion block

 

[hoodride]

If you wouldn't mind taking a picture that would be sweet

 

[bp71k5]

Ok, picture.


You have a 10si and mine's a 12si but I think the wiring is the same.

Big red wire goes to power junction block (or battery)
White wire (terminal #2) is the voltage sensor and should be connected to +12V near any big draw items. For example, if you're winch is wired to a distribution block, run the wire to that block. If you have a bunch of stuff wired directly to the battery, run it to the battery. If you have nothing extra, it probably doesn't matter so just run it as a separate line to the battery.

Blue wire (terminal #1) is the switched ignition power (+12v). It should only get 12V when the key is on. That wire will head up into the dash somewhere and may not be the same color.

If you're going to run a winch, you should probably upgrade to a more powerful alternator. I'm using a 93A 12SI and it runs all of my electronics including about 800W of amplifiers at full blast while idling and is still charging at 14V.

You said electrical wasn't very friendly for you, but this article explains a lot. I used it as a guide for mine and it's working better now. http://www.madelectrical.com/electricaltech/remotevoltagesensing.shtml

 

[hoodride]

Thanks so much, HUGE help. Regarding getting a alt. with higher amperage, I decided to wait on that as my winch is inoperable, and fixing/replacing it is toward the bottom of my list. It was only $40, so if/when I upgrade I'll just keep this as a spare.

I actually went to the library yesterday and looked at some blown out diagrams of these alternators and some wiring schematics, I'm getting way more comfortable with this electric stuff after figuring out what everything is for and some proper tools to eliminate the guess work. That said, I still wont do it unless I have to

Again, I really appreciate the help (and pic)

Grant