Does anyone know if an isolator for the 12 volt line going to trailer plug is standard as part
of the trailer tow package? I looked aroound and dont see any ..but, that doen not mean it
isnt hiding out of sight somewhere. Thanks in advance for any comments.

 

To my knowlege an isolator is not part of the trailer package. I have the trailer package and there is no isolator.

 

A typical 12v isolator will not function properly unless there is a balanced load (a battery connected to each output terminal) on both output terminals. Since a trailer with a battery won't always be connected to the trailer harness, an isolator will not work in this application. You will not find a towing package trailer harness equipped with an isolator. Some guys do add a HD solenoid to the battery positive wire in the trailer harness so that when the ignition is off, the trailer won't drain the truck batteries and when the ignition is on, the truck will charge the trailer batteries.

 

Try one of these... The're even built up in your neck of the woods... Very good company.
http://www.surepower.com/separator.html
Distributors prices range all over the place... Factory price was WELL over $100.00.
One of their distributors in Houston (Tracy Electric) was half that price.(~$47.00)

Keith

 

Why wouldn't an isolator work with only one battery hooked up? All it is is a diode to each battery from the alternator lead which prevents one from drawing from the other but both can feed from the alternator. One side would not affect the other which is the purpose.

 

H-I-D, that's true but each diode isolated leg is .6volts voltage forward drop(unless it is a Shottky type which will be .4v drop).
Some vehicle alternator regulation systems make it a Royal PITA to install an "Isolator" in them. The trick is to keep from hosing up the alternator's voltage & current regulator sensing scheme for the vehicle battery. If you don't watch out and get things just right, you wind up reducing the available battery charging voltages by .6volts!
Those Isolators were simple to use in the "old days" before those confounded computer controlled, current sensing alternators came along.

The battery SEPARATOR is a far easier system to install for a remote battery and load like an RV or winch battery.
Just 3 connections! truck battery #1, RV battery #2 and ground #3.
If you are using the existing #12 trailer hitch wiring, just make sure to mount the separator on the truck wiring side to keep any trailer wiring induced voltage drop from prematurely "separating" the two systems under load.

They make two 12volt models. One model only monitors the truck battery to control the contactor and the RV compatible model which will sense a charging battery from either direction, the truck or the RV.

Take a look at their website and you'll see...

Keith