Isolator vs switch vs unplugging - ref. and fan questions.

luvmymanor1 · 07-01-2011, 02:53 PM

I appologize if this is a repeat but I could not find my answer through the search.

In my current setup 2005 2720, the ref. and fan will be drawing power from the 12V battery on the toung of the TM. so as we are driving the alternator is providing power back to the battery of the TV and the TM, BUT, from what I'm hearing there isn't enough power to recharge the TM's battery while running the ref. and the fan. Is thsi true? are others having similar issues?

My question is... is there any chance that when we pull over the TM's ref. and fan will continue to draw power from the car's battery when we turn off the TV??? from my understanding when you shut power off the TV the lights and all power is off. so it would make sense that the TM would then continue to draw power from the TM's on board battery not from the cars battery. Is this correct?

07-01-2011, 03:33 PM

No, your umbilical cord from the TV to the TM is always hot, the 12V line does not go thru the ignition, (at least on my TV) it will draw from your TV battery and politley discharge it for you if you leave the car too long. I have been traveling the last couple weeks running the frig on battery power while traveling, if I'm away from the car for more than 15 minutes, I have been unplugging the cord from the TV and letting the TM run on it's own battery. Several have posted about putting a cutoff switch in line with the 12v line from the TV so it can be switched off easily.
Running the fridge this way with the fan on has been working well for us in very hot humid weather.

luvmymanor1 · 07-01-2011, 07:49 PM

Quote:

Originally Posted by Redhawk

No, your umbilical cord from the TV to the TM is always hot, the 12V line does not go thru the ignition, (at least on my TV) it will draw from your TV battery and politley discharge it for you if you leave the car too long. I have been traveling the last couple weeks running the frig on battery power while traveling, if I'm away from the car for more than 15 minutes, I have been unplugging the cord from the TV and letting the TM run on it's own battery. Several have posted about putting a cutoff switch in line with the 12v line from the TV so it can be switched off easily.
Running the fridge this way with the fan on has been working well for us in very hot humid weather.

really? I'm surprised... this seems incorrect to me. it should actually turn off or at least be set to turn off if you shut the engine off. This could potentially strand you out in the middle of no where and you need to take an emergency stop...

oh well just another glitchy thing to remember when hitching the TM.

ThePair · 07-01-2011, 08:27 PM

Some vehicles have a relay that will prevent draining the TV battery if the ignition is off. My TV is hardwired directly. Obviously you need to know what your situation is.

On the other hand, installing a fridge cutoff switch is quite easy to do, there are plenty of posts. I just switch the fridge off whenever I stop, and I've never had an issue.

luvmymanor1 · 07-01-2011, 10:14 PM

Quote:

Originally Posted by ThePair

I just switch the fridge off whenever I stop, and I've never had an issue.

How do you do that from outside the TM??? or do you have to open the TM up in order to do it?

07-01-2011, 10:22 PM

really? I'm surprised... this seems incorrect to me. it should actually turn off or at least be set to turn off if you shut the engine off. This could potentially strand you out in the middle of no where and you need to take an emergency stop...

oh well just another glitchy thing to remember when hitching the TM.

When I had my 2720SL I always pulled the cord from the TV to TM. If I was stopping for lunch at a fast food place. Stopping for gas, I just tried to do a fast job. Never had a problem. My brother has a coleman Popup and he does the same thing. Not sure though if his refer can be changed to 12v??

John

Barb&Tim · 07-01-2011, 10:56 PM

Originally Posted by ThePair

Quote:

I just switch the fridge off whenever I stop, and I've never had an issue.

Quote:

Originally Posted by luvmymanor1

How do you do that from outside the TM??? or do you have to open the TM up in order to do it?

He added an outside switch to be able to turn off the 12v going to his fridge and fan without having to open the TM. I liked ThePair's mod and adapted it to my TM.

Just search for "outside fridge switch" and you should find numerous posts on the subject.

Tim

**Bill** · 07-04-2011, 04:29 PM

OK, let's back up, boys. The question is, when I switch off the ignition key in my tow vehicle, does it continue to supply power to the trailer? The answer is another question - does your tow vehicle have an isolator relay? As tow vehicles come from the factory, some do, and some do not. My Explorer, for example, does have one - but many other equally-capable vehicles do not. LuvMyManor, you might consider adding your TM model and year, and tow vehicle info, to your signature line. It helps the membership answer questions like this.

If you have a test light or a test meter, you can check out the presence of an isolator by checking the battery-charge line in the 7-pin Bargman trailer connector at the rear bumper of the tow vehicle. Check it with the ignition on, and then with the ignition off.

If your vehicle does not have an isolator, then it is not to hard to add one if you are electrically handy. Otherwise, it is probably easiest simply to unplug the trailer when you stop, and then plug it back in before you start moving again.

Bill

luvmymanor1 · 07-04-2011, 07:20 PM

Quote:

Originally Posted by Bill

LuvMyManor, you might consider adding your TM model and year, and tow vehicle info, to your signature line. It helps the membership answer questions like this.

doing that right now... so no one has to dig up the info. TV = 2006 toyota sienna mini van...TM = 2005 2720.

oh and I will admit now that I know enough about electricity to get me into trouble

07-04-2011, 07:30 PM

Quote:

Originally Posted by luvmymanor1

TV = 2006 toyota sienna mini van...TM = 2005 2720.

I have a 2006 Sienna also and it was my tow vehicle for my 2720 before we got the Tundra. My Sienna did not come from factory with a tow package. If I am remembering the details correctly, it had a "tow prep" which consisted of a larger alternator and a transmission cooler. I had to install the hitch receiver and do all of the wiring myself using parts obtained from etrailer.com.

Since I was wiring it, it was simpler to not install an ignition relay in it. So on my Sienna, the hitch wires are hot regardless of ignition switch position. Did your Sienna come straight from factory with a hitch receiver and 7-pin trailer connector?