Need help, not sure if I am doing this right.
I 'm going to set-up dual batteries to power my winch and slide-in camper and I am in the process of wiring in a sure power isolator. I am not sure which wires come off the alternator and attach to the isolator. I have located the neg(-), but there are a few/couple smaller wires bundled with the positive. Any advice wold be appreciated.
Thanks
Richard

 

First off, welcome to the board, enjoy your stay.

Just a guess, but you must have a 1st gen, as 2nd and 3rd gens come with 2 batteries already,
year of truck will play a part in the accuracy of the answers to follow.

Someone with more knowlege than I will be along shortly.


phox

 

Yes and hi and thanks for the welcome
My truck is a 1991 d250 1st gen., which has been a great truck for what i,ve been doing. Arborist work mostly. I have hauled some pretty big loads and the truck has never let me down.

I just want to make sure that I wire in the isolator correct and avoid burning my truck to the ground. Is there an external regulator on the alternator that needs to be wired in or is it just a straight forward one wire off the alternetor job.
thanks again
Richard

 

If you are installing this on the original ND alternator, then it is the larger stud that is surrounded by the plastic boss, (left alternator black plastic thing on its right side.) this is the output terminal.
You could pick it up where it connects to your battery but the wire is too small and already a voltage drop. I connected mine directly to the alternator terminal using #4 welding cable




Are you using an ISOLATOR or a SEPARATOR? I have the latter.
The connections are a bit different with each but they all need the feed from the alternator to be a good one because of the voltage drop in the factory harness and because they are using high current diodes you will loose about 1 volt to each battery.
Be sure your charging system is in good shape and charging well.



Jim

 

Thanks
very helpful info. and even better with pics. So if I hook the output from the alternator to the isolator I'm good to go with hooking up the batteries?

 

Yes, depending on the unit you have you would connect the alternator to the ALT terminal and the main and auxiliary batteries would connect to the terminals #1 & #2.
Now if you are installing a diode ISOLATOR (big finned aluminum heat sink with 3 5/16 studs on top) you could install a 100 amp solenoid between #1 & #2 terminals and wire a push button in the cab and you would have the ability to use both batteries to crank, get the power for the push button from the auxiliary battery.
Be sure to use a heavy gauge cable from the isolator to each battery.

120-105711 White Rodgers {these are the same relays used to power our grid heaters}
http://www.grainger.com/Grainger/wwg...784827&ccitem=
Jim

 

Here's a whole-hearted endorsement for the Sure-Power Battery SEPARATOR approach!.
You'll LOVE the ease of installation... No screwing around with the alternator wiring and trying to get the correct charging voltage for all batteries when using an ISOLATOR..
They now make several separator models for your needs.. I bought the smaller, unidirectional model 1314 as I don't have an RV with a battery charger/DC power supply. (it looks exactly like the one Jim Lane shows in his pic)
Also, it is nice to be able to override the controls and tie all batts together in an emergency with a small switch.

K.

 

I think I have finally found the almost perfect solution for battery charging using the Sure Power SEPARATOR, having used the big 240 amp schottky diode unit
www.surepower.com/pdf/180031b.pdf
to charge all of my batteries with 100 amp relays to shunt the diode so I could parallel all my batteries electrically. The SEPERATORs do this automatically and will not charge the aux. batteries until the main reaches a preset voltage; I can use 2 small switches to connect ALL 3 batteries together.

Because the SEPARATOR is only rated for 100 amps I installed a 100 amp relay in parallel
http://www.grainger.com/Grainger/wwg...784827&ccitem=
{since the picture} with it since my alternator can put out in excess of 150 amps. I talked to tech support at Sure Power and they liked the idea.
Jim

 

Jim, since I bought my original separator, they have come out with a 300amp model that looks just like their big 24volt 300amp model except it's for 12volt service.

K.