Has anyone wired in a battery isolator? I wired one up in my LB7 swapped 85 and I'm now getting the red battery light. The brown wire on the back of the alternator is the exciter wire, right?
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Battery Isolator???
- Thread starter Kspen90
- Start date
You must also provide a battery sense wire if you run an isolator. With an isolator there will be no voltage to the alternator at the charge post unless the alternator is putting out. Also you must have a voltage sense wire as a battery isloator will have a .8-1.2 volt drop from the alternator to the battery depending on output amps. All it is is a giant diode mounted to a heat sink, and it takes a certain amount of volts for the diode to transfer electricity. So if you put 13 volts into it, it will drop about .8 volts at light loads and only put out 12.2 volts. Sounds like you need to hook up the voltage sense wire so your alternator can charge. People run into this on motorhomes and such with 1 wire high output alternator conversions.
Sorry, I'm not very savvy to these types of wiring applications. Where would I locate a voltage sense wire to hook to the alternator, and where would I hook it to on the alternator?
What alternator? Since you say LB7, is the ECM fielding the alternator or did you wire it direct?
The ecm is. From what I'm reading, I need to hook the generator duty cycle wire to the delcotron sensor post on the isolator, correct?
Are you sure the alternators good? Have you tried removing the isolator and seeing if its charging? The ECM should provide the neccesary trigger and battery voltage sense signal to the alternator to make it work I would think.
The alternator was working right before I installed the isolator. I'll go reconnect it the way it was before and check to see.
Not 100% on your 02, but I know my 01 only used 2 of the 4 pins in the alternator plug(the 2 in the center). You will need to change out your current plug to a true 4 pin one as GM's isn't opened in the outer 2 pins(at least my 01 wasn't), and add in a wire hooked to the main battery to the S pin in the alternator plug. This should take care of any charging issues with an isolator installed. Heres a thread to reference in post #6 to give a better view.
http://www.fullsizechevy.com/forum/general-discussion/performance/480432-ad-230-ad-244-a.html
http://www.fullsizechevy.com/forum/general-discussion/performance/480432-ad-230-ad-244-a.html
alternator checked out good. Here are the online instructions for the isolator. I'm concerned if I hook it up the way they suggest, it might burn something up in the ECM due to the way the alt draws its excitation from there.
http://www.allbatterysalesandservice.com/graphics/Instruction-180012Q.pdf
http://www.allbatterysalesandservice.com/graphics/Instruction-180012Q.pdf
Mine also only has 2 pins, and Ive already added the third pin, but I'm afraid to hook up an additional excitation wire as per the instructions.
From the sounds of it, it looks like the excitation wire supplies power back to the charging lug of the alternator which may be what is needed to properly field the alternator. I would start it up, then jumper the excitation wire to the hot side and see if it then puts out, if so you know that is what it needs to charge.
What are you trying to accomplish with the isolator, did you add another battery to your truck ?
if you added a house battery this is a cool little device.. runs off your cranking battery to charge house battery up to 15 amps while cranking battery is being charged.
http://www.xantrex.com/power-products/power-accessories/auxiliary-battery-charger.aspx
if you added a house battery this is a cool little device.. runs off your cranking battery to charge house battery up to 15 amps while cranking battery is being charged.
http://www.xantrex.com/power-products/power-accessories/auxiliary-battery-charger.aspx
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