Battery/Alt question

[jleger98]

On my 97 PRE2150WT, I just installed my stereo system. The last thing I did was hook up the battery isolator.....well almost. Here is the problem. There is only one lead that goes to the pos side of the battery. So how do I hook the isolator up?? So I have to run another wire? There is a a(maybe 8 or 10ga) orange wire that comes off the back of the alt, but it gets combined into a wrapped series, so I can;t tell where it goes. Anyone have any thoughts here? Otherwise I have a brand new 140 amp isolator for sale

[Domsz06]

did you look at the post sp put up on my wiring questions?

[jleger98]

Not sure I found the right thread. You got a link to it?

[chpthril]

On my 97 PRE2150WT, I just installed my stereo system. The last thing I did was hook up the battery isolator.....well almost. Here is the problem. There is only one lead that goes to the pos side of the battery. So how do I hook the isolator up?? So I have to run another wire? There is a a(maybe 8 or 10ga) orange wire that comes off the back of the alt, but it gets combined into a wrapped series, so I can;t tell where it goes. Anyone have any thoughts here? Otherwise I have a brand new 140 amp isolator for sale

You need to find where that wire off the back of the alt goes because that is the wire that will attach to the center post of the Iso. I would think the Pos post of the starting battery first, next, maybe it is going to the starter or a power buss?

After you find and attach the charge wire to the Iso, then you will need to run a cable from the 2 outer posts to each of you batteries.

wish I could tell you where that orange wire is going good luck

[R&T Babich]

I just finished the wiring on our 2000 21V this morning. Added a second battery, isolator, accy breakers, 2nd bilge pump, & a shower pump. The #8 orange wire on our boat went from the alt into the wiring harness and showed up at the starter. There was also a #10 red cable connected there that I think goes to the 50A breaker. 12v power would come from the battery lead to the starter post, out the red lead to the 50A breaker and out the orange lead to the alt. Actually the alternator doesn't use the power, so once the engine is running the alternator pushes back with 13.5v into the battery for charging and out the red for running the boat. At first I mistakenly lifted the red and orange from the starter post, tied them together and ran a wire to the isolator. The orange wire only needs to go to the center post of the isolator. Leave the red lead there or run a second wire back to the main battery. The #1 and #2 posts of the isolator need to be connected to the #1 and #2 batteries, somewhere, with #8 wire. I had added a master battery switch for the starter so I tied the isolator connections in there.

[spharis]

With an isolator, it is best to run a new wire from the alt to the isolator, and leave the other alone. Chances are your wiring right now is set up with a main wire from the battery to the starter lug, and starter lug to alt.

I would have suggested using a battery combiner, as it requires no new alt to battery wiring, and does a great job of isolating as well.

[jleger98]

yeah, I have the batteries wired up to the iso already. Just didn't make sense to run the one red lead that normally goes to the batt to the iso.

So If I follow this correctly, the alt actually charges back over the same line that everything gets powered off?

That said, then I should simply add a wire off the orange lead on the alt and bring it in to the center iso post and I'm good, right? No other rewiring required?

[spharis]

Yes you could jump from your starter to the iso, and it should combine OK. I don't know if there is a problem wiring that way or not.

[chpthril]

yeah, I have the batteries wired up to the iso already. Just didn't make sense to run the one red lead that normally goes to the batt to the iso.

So If I follow this correctly, the alt actually charges back over the same line that everything gets powered off?

That said, then I should simply add a wire off the orange lead on the alt and bring it in to the center iso post and I'm good, right? No other rewiring required?

If you run a new cable from the "charge" lug of the alt to the Iso, than you need to disconnect the original orange cable at both ends so it is dead.

sounds like you are making "heads and tails" of the project.

[jleger98]

ok, so if I simply disconnect the orange wire from the alt, and run a new one to the iso I should be fine. I guess I would cap the orange wire or disconnect it from the other end so I don't have a "hot" wire anywhere. Would that affect my gauges? I think its an ammeter....might be volts though.

[spharis]

The best thing to do would be to remove it completely. Unhooking both ends is fine.

I doubt you have an ammeter, but no it will not affect a voltmeter.

[chpthril]

ok, so if I simply disconnect the orange wire from the alt, and run a new one to the iso I should be fine. I guess I would cap the orange wire or disconnect it from the other end so I don't have a "hot" wire anywhere. Would that affect my gauges? I think its an ammeter....might be volts though.

Yes, disconnect the orange at both ends.

Factory current flow goes like this: Alt - orange cable - starter lug - starter cable - battery - components.
New current flow: alt- new cable - Iso - new cable to batts - batteries - components.

Does this make sense ?

[jleger98]

Yep, thanks guys!!

[jleger98]

On a side note, today I took it out on the water for the first time this year.

The new system sounds unbelievable. Even had one guy come over at the dock and check it out. Said he heard it out on the lake.

[chpthril]

On a side note, today I took it out on the water for the first time this year.

The new system sounds unbelievable. Even had one guy come over at the dock and check it out. Said he heard it out on the lake.