Rookie Mistake 102

[Doc Wood]

Hey, no worries, you aren't the first or last to do that! I did it, twice before I figured out what had happened. Imagine waking up a 5 a.m. on the NY Throughway rest area with a dead battery! Fortunately, one of my first purchases, and I highly recommend this, was a mini charger that I carry in my car. Jumped the car just fine--of course also set off the alarm as I had opened the door with the key and not the clicker so I woke up the truckers parked next to me.

One thing on this thread I do disagree a bit with. I never run my frig on propane while driving. Too many horror stories and who needs a live fire in your trailer while moving down the road. the 12V does just fine, you just need to remember to either shut off the frig at night if you can't plug in or don't want to bother with the propane.

[computerspook]

Originally Posted by Raspy

Lisle,

Everything fits together except why the car died while driving. Once running, the car battery should not go dead.

It is probably not a good idea to ever run the fridge on 12 volts. Not many vehicles send enough power through the seven pin plug to support that, and while plugged in, running it on shore power is better. While out camping, propane is best.

Absolutely something else wrong. Actually sounds like a flaky alternator. Now charging the camper battery from the alternator may damage it if it is under powered already. But a good alternator.


Actually I run my frig on 12 volt while on the road a lot. It does take a good connection. But generally most well wired 7 pin connection should handle that fine. I have at a lot of trouble with this kind of thing until I learned the important truth on that. An electrical circuit is an electrical CIRCUIT. It has to be a circle and a completed circle. It is only as good as the worst part of the circle. And generally the worst part of the circle is the ground side and usually right at the connection. Check your ground connection wire on your plug. The see how it is run for the car. A lot of times it is very light wiring and then screwed to the frame with a bad connection. Hook your ground up with a wire a bit heavier than the other wires. And then make sure it goes to a good ground point. Not the frame can work well. I usually run it into the cab of the vehicle and ground it out of the weather. Either way clean the connection point and the connector on the wire. I generally solder this connector on. Then tighten it down. Where possible I use stainless steel. Then I paint or under coat the connection. Don't forget the back of the screw point. Your car will thank you.

[Len S]

[QUOTE=AC0GV;766219]

Originally Posted by Lisle

So I've been full time in my Casita 16' since September. I went thru the RV Online University, RV101 class, and read the Casita manual. Nowhere in there did it mention that I should unplug my camper from my tow vehicle overnight. (Or did I miss it?)


It will depend on the tow vehicle and who wired it. Many factory wired 7 pins disconnect the "charge" pin when the engine is not running.

Agree with Ken that it all depends how he 12v power line is wired to the car battery from the trailer . If there is a relay that did not open circuit but kept the circuit closed when the key was turned off that that is the issue. Not hard to check with a voltmeter . Also more smaller new trailers do not have the 12v feature on the fridge , only 110vac and propane.

[Peder_y2k]

I think the fuse blew from high resistance in the trailer feed wiring. Excess electrical load will do that with inadequate wiring.

[gordon2]

Originally Posted by Doc Wood

..
One thing on this thread I do disagree a bit with. I never run my frig on propane while driving. Too many horror stories and..

Please provide links or leads to these horror stories about fires started by a fridge on propane when on the road. In all my research I could only find one, and it was a unique case in that the RV (with fridge running on propane) was actually stopped at a gas pump and somehow someone splashed gas from a gas pump hose into the fridge vent.

Of course there are too many cases of RVs and campers catching fire but usually the cause is something else, or, if it is the fridge, it is because it is defective and being on the road had nothing to do with it.

Originally Posted by Doc Wood

... and who needs a live fire in your trailer while moving down the road...

I do for one. If I want my food unspoiled. My fridge runs on 120 VAC or Propane ONLY. And it does not retain cold very well.

BTW, I did buy a portable 120/12 volt Danfoss type fridge so I can sometimes avoid using the fridge in the camper,. After all having the tank off is best. However my portable fridge is pretty small.

I just think the risk of using a propane fridge on the road is often over stated but I'm always interested in hard evidence.

[jerrybob]

I run our fridge on propane or AC...never DC. Also.....I always unplug the trailer if we're gonna be gone more than an hour.....easy to do...keeps you out of trouble.

[Dennis McMillan]

Had a similar occurrence in our Scamp 13. Our TV is an older Jeep Grand Cherokee with factory tow package. Solved it by installing a relay in the hot lead that closes when the running lights are on. Just need to remember to turn the lights on when we leave the drive. When we stop the Jeep reminds me that the lights are on when I take the key out of the ignition. No problems since.

Dennis.

[Gompka]

I know some people have successfully run the fridge on 12v while driving, but it's horribly inefficient on dc and from my testing my 105 amp hour deep cycle can only run the fridge on 12v for about 4.5 hrs before its at 50% capacity. Don't forget the lower the voltage gets the more power the fridge uses. For example on a 12.8v freshly charged battery your pulling 120w/12.8v = 9.375 amps, as that battery gets to 11.8v your pulling 120w/11.8v = 10.169 amps. When your running on 120v shore power, your also using a seperate 120w heating element but then your amperage is 120w/120v = 1 amp, much more efficient. I tow with the fridge on propane and have done so successfully for a couple of years now, i don't want to open up that can of worms so just saying its what I choose to do, not persuading or dissuading you on that one

[Glenn Baglo]

Originally Posted by gordon2

Please provide links or leads to these horror stories about fires started by a fridge on propane.

Yes please do provide links to respected sites, like propane associations, government motor vehicle and motor vehicle act sites. Exclude forums where anonymous members make assertions without verification.

[JaxDan]

I can feel for y'all as last week at the Swanee rally my tow vehicle battery died and it was not even connected to the Casita...the house battery did not have enough to start it so thankfully a neighbor got me going with a jump and Auto Zone had the right new battery. What I learned is the new pickups have a 110 V generator under the hood and one of the folks there showed how he has a separate switchable 110 V plug in for the fridge so it can operate while on the road. This is great with the older 2 way fridge but the new ones might still revert to battery when stopped and the engine is off. One possible mod may be to just remove the 12 V heating element - that way when the generator is not supplying current the 12 V system won't function. Nice to see what others can do, my old war horse tow vehicle is not all that sophisticated.

[computerspook]

Originally Posted by Lisle

And he told me that yes, leaving the car connected to the camper and running electrical stuff in the camper can drain your car's battery. Finally I understand. So be warned, newbies, and disconnect your car from your camper overnight if you're running electrical things in the camper. In this case, it's been cold here, I was running the electric fan on my propane heater, as well as the water pump and the frig on 12V. Cost me $1400 in repair bills and RV campsites while the car was in the shop. Sighhhhh.

If you are are running on battery absolutely. Some people say that when the car is not running the battery is not connected. It is for all of the vehicles I have dealt with. But this can also be good. If you have ac power you can charge the car or even use the items in the car such as the lights without actually discharging the battery.

Now I have a box that I use with my scamp. It has a 7 pin rv socket on it. It has a switch and two side marker lights. The switch is a three position switch. I take the battery connection line and run it to the switch. Middle is off. Up turns on one of the lights and the break lights. Down turns on the running lights and the other light. That way I have a light on the front of the camper and the lights are all on so that I can be more visible when camping in unusual areas. Yes I had an experience that caused me to invent this ;-) But it also lets me test the lights before I go somewhere.

[gordon2]

Originally Posted by Glenn Baglo

Yes please do provide links to respected sites, like propane associations, government motor vehicle and motor vehicle act sites. ....

Yes please do... I am still waiting.

We all agree that having the tank valve off is safer. In fact having the tank removed from the trailer is even better. And having no gas in your tow vehicle makes the vehicle very safe. But in each case functionality suffers, so there is always a trade off. People have many fears which are often quite unreasonable. Stay home (and in bed) if you really want to be as safe as possible.

Reasonable risk management using hard data is best and to the end I am waiting for real data. How many RV fires where attributed to the use of propane when on the road? How does that risk compare to the very act of driving, taking a walk in the woods, etc. How many people have been killed by lightning, shark attack, or absorption fridge fires (on gas, not electric).

If you have the option to keep your food from spoiling and making you sick, without the use of propane on the road, then thats great. If you don't, then its fair to assess the risk vs. reward. Lets assess it fairly.

[Gompka]

Originally Posted by JaxDan

I can feel for y'all as last week at the Swanee rally my tow vehicle battery died and it was not even connected to the Casita...the house battery did not have enough to start it so thankfully a neighbor got me going with a jump and Auto Zone had the right new battery. What I learned is the new pickups have a 110 V generator under the hood and one of the folks there showed how he has a separate switchable 110 V plug in for the fridge so it can operate while on the road. This is great with the older 2 way fridge but the new ones might still revert to battery when stopped and the engine is off. One possible mod may be to just remove the 12 V heating element - that way when the generator is not supplying current the 12 V system won't function. Nice to see what others can do, my old war horse tow vehicle is not all that sophisticated.

Unfortunately, the new vehicles are just using inverters. So yes your using only 1 amp at 120v but to get from 12v to that 120v your using even more than 10 amps because of conversion losses. I'm sure they just make up for this with a very large alternator, but can't get around the physics of it.

[charlsara]

Or you could just get a 12 volt compressor fridge. Our Truckfridge TF-130 will run for three to four days off my 2 six golf GC batteries.

[nefldiver]

Wow this form is great I always learn something. I always use propane when traveling and not hooked up to shore power. My dometic fridge keeps ice cream rock hard on propane alone. The thing I didn't know and never thought about was turning it off when I go to the gas station!!! Leaving it on is like standing near the pumps with a Bic lighter burning. It never occurred to me, and I am the first to tell people to put their cell phones away while they're pumping gas.

[Rzrbrn]

I have a 2011 Toyo Tundra with tow package, 5.7L engine. I read about disengaging the 7 pin when parked, so I did for awhile. Then I forgot one time and nothing happened. So when I got home I experimented. Now I never pull the 7 pin when parked and no problems whatsoever. Also the truck charges my trailer battery just fine while driving. I set the fridge to automatic and forget about it.

[nefldiver]

An interesting fact I learned a while ago was dot-dot-dot why do women experience way more fires at the gas pump then men? Is because women are more likely 2 go back into their cars sliding across the seat and more than likely a synthetic fabric, then they get back out and go to touch the pump handle, and the static spark ignites the fumes. Don't believe me look it up on Snopes

[Shannon Thompson]

Lisle,

Thanks for sharing your learning curve.... everybody has them. My biggest rookie moves were:

1. Forgetting to raise the hitch foot after hooking up the trailer, and then driving out of my driveway. Quickly realized mistake with terrifying jolting/scraping sound and the car being bounced all over. Amazingly and thankfully it did not pop the trailer off the hitch ball and nothing sustained damage (except my pride).
2. Forgetting to chock the wheels before unhooking from my vehicle and watching in horror as the trailer began to roll away from me down a slight decline.... Thankfully it only rolled a couple feet before stopping. I nearly passed out.

These, even after a few years of camping experience AND my hook-up and unhooking checklists that I review each time.

[Penny in Montana]

I am really thankful to have that information. I always travel with my frig on 12 volt. I thought that is what it is for. I do cool it off with the home 120 before leaving home. So far no issues but thanks to your help, I will switch to ice or propane.

[gordon2]

Originally Posted by Penny in Montana

I am really thankful to have that information. I always travel with my frig on 12 volt. I thought that is what it is for. I do cool it off with the home 120 before leaving home. So far no issues but thanks to your help, I will switch to ice or propane.

No need to switch if it works.. if the fridges works on 12 VDC with sufficient power from the tow vehicle, and does not discharge the tow or trailer battery, then you can use it. Just remember to turn the fridge off of 12 volts and/or disconnect the tow vehicle umbilical cord when you have the tow vehicle off for more than a short time or get a battery isolator or relay.