Which alternator wire is for the isolator? (1 Viewer)

[80cruiserscool]

Am hoping someone can tell me which wire of the three, that go to the alternator is supposed to supply the excitement to an isolator?

 

[Landpimp]

the wire on the post(not the plug) is the alt charge wire.

 

[80cruiserscool]

The isolator I have has four posts. one is supposed to come from the alternator wiring to give the isolator knowledge of when to c harge the system.

help?
Product Family: Battery Isolators
: 48122
Description: Battery Isolator






Picture shown may differ from the listed part.



Top View



Front View



Side View

Specifications
Details Isolates loads of 2 batteries, allows charging from 1 source
Rating 12-36V DC; 140A max. alternator rating; negative ground electrical system only
Terminals three 5/16" studs and one #10 stud
Size 6"L x 4-3/16"W x 3-11/32"H
Min Qty No
UL Listed not listed

 

[80cruiserscool]

tried to send pictures of the isolator evidently did'nt work!
here is a link though if anyone can help me understand!
http://www.colehersee.com/resource/index.htm
thanks

 

[Hltoppr]

On a 1992:

The excite wire is in the harness. You'll need a wiring diagram to figure out which wire it is. On my 1992 IIRC it was purple and black.

 

[80cruiserscool]

great pictures! always help
it looks like you ran to as circuit breaker?
what size is the breaker your using ?
Thanks

 

[Landpimp]

sorry I misunderstood what you were looking for, I have no clue which wire you need, I know nothing about isolators.

 

[lovetoski]

I have a 4 post isolator on my 80 also. The charging wire from the alternator is like pimp described. The "sensing" wire is the non-obvious one, but very important. You run an 12 ga (I think - check you installation instructions) wire from the sensing post on the isolator to the 7.5am charging fuse in the black fuse box on the DS fender. You'll need a little brass clip to enable you to connect a female spade clip to this fuse.

The function of the sension wire is to detect system voltage, and inform the alternator. The only wierdness in this set up is that the alt doesn't put out enough to "energise" the system until you rev the motor to ~1500 rpm. So, when you fire it up on a warm day (or when the motors warm) it won't reach 1500 rpm until you give it some gas. Until you exceed 1500 rpm, a bunch of dash lights will be lit up, and when this first happened to me I was sure I'd fawked something up good!

Maybe there is a better way to wire this up, but I followed the instructions in the tech section - check it out there are some articles on dual battery installations.

HTH.

 

[80cruiserscool]

I've gone through all of the tech articles but still dont understand the wiring to a isolator?
I'm ready to do the jump to duals but I dont want to screww something up!
Any help is greatly appreciated!
Thanks

 

[80cruiserscool]

landpimp,
what is the green wire coming from that is on your picture?

 

[80cruiserscool]

:whoops: sorry that is Hill topper's pix's I'll pose the question to him.
where is the green wire coming from that is going to the isolator.

 

[lovetoski]

Your needs should drive the choice as to how you set up a dual battery system. In the case of my wife's 80, she wanted to have a portable heating/cooling unit in the back (to heat and cool drinks and food). This is left plugged in sometimes all day, and we still want the car to start at the end of the day. But, key point for her, she wanted it really simple - plug the cooler in to make it work, unplug it to make it stop. I installed an aux power outlet in the rear, and it's wired to the second battery. Works great. I think a lot of people would love this setup. (Not just landcruisers).

An isolator has the advantage of being invisible once you install it. No switches, just drive the car. There is a voltage drop, but with the 4 post isolater you can still get correct voltage to the electrical system. The alternator (voltage reg actually) compensates by sending higher voltage to the isolator. Voltage into the isolator (from the alt) is 15 - 15.5V. Voltage out is 14-14.5V. The voltage drop is dissipated as heat.

The green wire in hilltoppers pic is probably the voltage sensing wire. The other end goes to the black fuse box (also in the picture), and is probably connected to the 7.5amp charging fuse.

 

[80cruiserscool]

Doug,
thanks for the info!
so what your describing is you have two posts for the batteries directly then one post uses the alternator output cable. the question I have is the fourth post which is the excitor. Can I use the 7.5 fuse that George's link talks about as the ignition switch wire on the isolator?
I'm not sure if that is correct or am I completely off!

Thanks for your help!

 

[lovetoski]

Can I use the 7.5 fuse that George's link talks about as the ignition switch wire on the isolator?

You got it!

 

[Hltoppr]

The green lead goes to the "excite" wire on the back of the alternator plug. IIRC it was the purple and black wire in the loom. You'll need to check out the wiring diagram for your vehicle and see which wire is from the ignition to the alternator.

-H-