Battery Isolator - Have one??

[Wendell Ann Hanks]

How do I(we)know if our trailers have a battery isolator?
Ours is a model 560, built in August, 2011.
Problem: Our 2014 Highlander, with factory hitch and wiring, does not charge our trailer battery. However, all the brake& signal lights work when driving

Help from Cary:
Cary's insightful observation maybe the reason our trailer may not be charging when towed:
"If your trailer is equipped with the optional battery isolator it might not be turning on due to the charge voltage on the tow vehicle not being high enough to switch it on...the turn on voltage is 13.4. So, if you are reading 13.5 or less at the 7 pin on the tow vehicle you will likely run into an issue if your trailer is equipped with the isolator option the isolator needs to be bypassed out to make the charge circuit work."
I presume the "isolator" on the trailer and how it is it bypassed? -- and does it need to be activated once driving has stopped?
The learning saga continues!
Thanks,
Wendell

 

[rotus8]

Probably the easiest is to ask Cary if your serial number had one installed at the factory.

The more direct way is to see if it is there; Open the right galley storage bin under the counter and take out all the stuff you have stored there. Remove the screws holding the panel on the right side inside the bin and pull the panel away from the side; it will still be attached to the battery disconnect switch so just hold it aside. Inside you will find the battery and the fuse panel. If you have a battery isolator, it will be there too, attached to the back of the compartment. Mine is a dark grey/black box with cooling fins, about 4" square with a bunch of wires connected to terminals with nuts.

 

[dhutchin]

I have a battery isolator installed under my truck. I had an issue with my battery not charging. It turned out that one of the wires to the isolator had rubbed and become corroded.

 

[Cary Winch]

Wendell,

I did a quick check of your original build sheet. Yes, your trailer does have a battery isolator.

We have been seeing issues with some of the newer Toyota products with factory 7 pins on them. For some reason Toyota is regulating the voltage on the charging line. The measured voltage is right at the point of not always allowing the trailer's isolator to turn on. In a case like this we would recommend bypassing the trailer's isolator. You probably have a charge line relay in the Highlander any how making the trailer's isolator redundant.

Cary