refridgerator question?

[outdoors5]

I have the typical three way pu refridgerator.  If the refridgerator is set to 12v when driving will I drain the pu battery or the tow vehicles battery or is the refridgerator using the tow vehicles electrical system, thus not using any battery?  
My second question is about using the propane setting, it has been a long time since I tried this.  On my last trip the cg lost power so I tried propane and I belive it did not light.  I was looking through a small swinging door for the flame and saw nothing.  Is this location correct?  Any ideas on why the fridge is not lighting and what can I do?  Thanks in advance for your ideas!

[austinado16]

Fridge function, use and performance has been a *hot* recent topic, so do a quick search here in the "Mr. Fixit" archives and you'll find a lot of info.  Infact, just scroll down a bit.

You're wiring to your camper from your tow vehicle should be supplying 12 volts only when the tow vehicle engine is running.  This power should be sent directly to your camper battery.  This way, going down the road,  your tow vehicle's alternator is both charging your camper battery and supplying power to your 12 volt fridge.  When you turn the tow vehicle "off" the fridge then just get's 12 volts from the camper's battery........and not from the tow vehicle.  But, the camper battery can probably only power your fridge for 3-4hrs before it goes dead.

Regarding lighting your fridge for propane use, yes, that little swinging door should show you a nice fat pilot light flame.

Try using a butane BBQ ignitor.........turn your fridge's gas valve to the "on" position, depress the button on the safety valve and hold it down, then swing the door out of the way, light your BBQ ignitor and stick it in over the little burner in there.  Leave the BBQ ignitor on, and keep holding down that safety valve button until you see a blue flame come on from the burner.  Once that blue flame starts, take the BBQ ignitor out and continue to hold down the safety valve button for about 15-30seconds so it's little heat sensing probe (a thermocouple) has a chance to get hot.  Then let go of the safety valve and you should have a nice steady burning blue flame.  Set the temp dial in the 4-9 range and *poof* you're making cold.

[outdoors5]

You're wiring to your camper from your tow vehicle should be supplying 12 volts only when the tow vehicle engine is running.  This power should be sent directly to your camper battery.  This way, going down the road,  your tow vehicle's alternator is both charging your camper battery and supplying power to your 12 volt fridge.

Just making sure that I am clear.  So, this means that it is not a problem to run your fridge on 12v while driving and I will not drain any batteries, car or camper.  Do I have that correct?

If so I wonder why the talk is always about questioning who runs the fridge on propane while driving.  If 12v is safe why not only 12v?



Quote:
 Try using a butane BBQ ignitor.........turn your fridge's gas valve to the "on" position, depress the button on the safety valve and hold it down, then swing the door out of the way, light your BBQ ignitor and stick it in over the little burner in there.  


Where is the gas valve?  Do you mean the selector switch that allows you to choose between plug in, 12v, or propane or is this an actual valve that I need to open?  If so where is it located?  (I do turn my propane tank valve on but it sounds like you mean something else.)

[waterdoctor]

I have a 3-way Dometic fridge in my pup and when driving only use the 12v system.  I have found that my tow vehicle battery drains down to the point the engine dies when I have the fridge running while enroute to the cg.  This is not a normal situation for most, but this particular tow vehicle is a late 60's pickup with a 45-50 amp alternator.  That's just too small to keep things in the truck running while trying to run the fridge, as well.  I've converted from the old Ford alt to a 100amp GM alt and that seems to have solved the problem.  As to operating the fridge on propane while on the road, I would not recommend it.  I've tried that too and discovered the pilot flame gets blown out (not a good thing!!!) and the raw propane could be smelled both in and out of the pup. The gas detector inside was letting me know it smelled it too.  About the lighting problem you indicated - for safety, when I'm breaking camp and turn the propane tank off, I always bleed off the line pressure.  Between trips, the lines will get some ambient air in them, so when you turn the tank back on the air needs to purge out. Since the pilot on the fridge is at the furthest point from the tank, it can take a few minutes to get all the air out at the fridge pilot.  I have to hold down the gas valve (which is also the same knob for setting the fridge temp) for a few minutes while holding the lit BBQ llighter at the pilot until it lights. You should be able to see the flame, but if that side of the pup is in the sun, it can be very difficult to see thru the little access hole.  I've read that the flame should be a fan shape. If not, then you may need to do some cleaning to get rid of soot buildup (see your manual for this procedure).

I'm still a rank amateur at this, so am still on a pretty steep learning curve.
I hope this sheds some light for you.  I'm still learning about all the ins & outs of this pup camping thing, having moved over from tenting and not having all the amenities of a pup.  Austinado16 mentioned in his reply that the vehicle battery supplies power only when the engine is running.  Since I did my own wiring, I don't see how that is the case for me.  I think that as long as my tow vehicle is connected to the trailer, there's power going both ways.  Maybe austinado16 can enlighten on this point?

[AustinBoston]

You're wiring to your camper from your tow vehicle should be supplying 12 volts only when the tow vehicle engine is running.  This power should be sent directly to your camper battery.  This way, going down the road,  your tow vehicle's alternator is both charging your camper battery and supplying power to your 12 volt fridge.  When you turn the tow vehicle "off" the fridge then just get's 12 volts from the camper's battery........and not from the tow vehicle.

This depends on the tow vehicle.  Some vehicles (actually, nearly all) have a "12V charge" line that is always on, which means if you park for extended periods of time with the trailer hooked up and on 12V, it will kill both the camper and tow vehicle battery.  BTDT.

More and more vehicles now days include a charge relay that shuts off the charge line when the ignition is off (sometimes part of the tow package), but most don't have it yet.  There is nothing to prevent owners from wiring in a relay for this purpose.

Austin

[AustinBoston]

[Just making sure that I am clear.  So, this means that it is not a problem to run your fridge on 12v while driving and I will not drain any batteries, car or camper.  Do I have that correct?

Your vehicle's alternator, the gauge of the charge line, the quality of the contacts, and corrosion in the contacts of the connector can conspire to compromise it, but in theory, yes, while the vehicle is running.  If the charge line is too small, or if the contacts are poor, then the fridge will get some of it's power from the charge line and get the rest from the camper battery.  It won't drain the tow vehicle battery while driving unless there is an electrical problem with your vehicle.

If so I wonder why the talk is always about questioning who runs the fridge on propane while driving.  If 12v is safe why not only 12v?

Mainly because the fridge doesn't work very well on 12V.  My fridge works better than most, but it still doesn't work well on 12V.  It's fine for a few hours, but expect the fridge to gain 15-20

[mountainrev]

As to operating the fridge on propane while on the road, I would not recommend it.  I've tried that too and discovered the pilot flame gets blown out (not a good thing!!!) and the raw propane could be smelled both in and out of the pup. The gas detector inside was letting me know it smelled it too.  

It's actually not a pilot flame, but a flame nonetheless.  However, unless it's an old camper, it operates on a thermocouple, which will shut off the propane automatically if the flame goes out.  Therefore, you shouldn't have a problem with propane leaking if the flame goes out.

My experience with my unit (Dometic 3-way fridge in an '03 Viking), however, is that I cannot operate the fridge on propane while the pup is popped down.  There must be a kill switch somewhere that shuts off the propane, or disables the thermocouple, or something like that.  Therefore, I do not operate my fridge at all until it is set up at the campsite, since I don't want to run down my TV and/or pup battery.  The downside is that it takes well over 12 hours to cool the fridge.  I'm planning to buy one of those battery-operated cube fans in the near future to aid in cooling.

[wavery]

Quote:
 Try using a butane BBQ ignitor.........turn your fridge's gas valve to the "on" position, depress the button on the safety valve and hold it down, then swing the door out of the way, light your BBQ ignitor and stick it in over the little burner in there.  


Where is the gas valve?  Do you mean the selector switch that allows you to choose between plug in, 12v, or propane or is this an actual valve that I need to open?  If so where is it located?  (I do turn my propane tank valve on but it sounds like you mean something else.)[/COLOR]

I have a 2002 Coleman and I believe we both have the same fridge.

The later model fridges (like ours) run quite well on propane while driving. I have never had our pilot blow out while towing. Even if it does, it is not dangerous (as previously stated).

I believe that you have a "RED" button igniter on your fridge (mine does). I simply depress the "gas selector switch" (on pilot) for 120 seconds (to allow the gas to reach the burner) and it will light on one click. Our burner is much different than austinado16's. The window is much smaller and it is harder to get to the pilot with a "BBQ igniter". In fact, most won't even go through the window and the pilot light is much harder to see. Besides, it just isn't necessary. Just give the gas a chance to flow.

[Dray]

A few things I'm gonna try this weekend on my trip are to use a couple peices of tape to hold both the vent up and another peice to hold open that little round window to see the flame.  It's quite challenging to hold up the vent while opening that circle view deally while trying to light the darn thing.

[austinado16]

Mountainrev that sure seems strange that yours won't work with the camper "down."  Might be worth finding out what you're loosing and see if you can get it dialed in.  Thermocouple's make their own voltage as they are heated and that voltage energizes a magnet in the safety valve portion of the gas valve (or a seperate safety valve like in my Dometic 2190) and once that magnet is holding the valve open internally, gas flows to the gas burner.

Regarding the question about the fridge draining the tow vehicle or camper battery while towing, no, it shouldn't.  But that's been covered already pretty thoroughly.  We just did a maiden voyage to the Grand Canyon.  Precooled for about 12hrs (over night and into the next afternoon) on propane, loaded up cold food, switched to 12v and headed off through centeral California and into the Mojave Desert.  It was well over 100*F and fridge temps went from the mid 30's here in the yard, to high 40's during the 2 days and 11-12hrs worth of driving it took to get to the south rim.  Even while camping and switched back to propane it didn't get into the 30's until we left the fridge closed for 2 days while we hiked to the bottom and back.  The tow home was similar with the same smoking hot outside temps and fridge temps in the high 40's.  Nothing went bad, and we had milk, eggs, and meet.  We were gone a total of 5 days.

As far as seperating your tow vehicle's battery from the camper battery when the engine is turned off, I've drawn up this wiring diagram using a standard Bosch 4 prong relay.  These relays are available with a mounting tab moulded into one side, so they can be easly screwed into the firewall or inner fender.

That valve, or valves I'm talking about are: 1) The gas valve that may be back inline just before your fridge's main gas valve.  It's just an on/off ball valve with a lever.  Turn the lever sideways blocks the flow.  Turn the lever inline with the gas line and that allows flow.   2) The safety valve, which is a seperate valve on mine with a spring loaded button that I have to keep pushed down while lighting the flame, and then hold it down for about 30sec to wait for the thermocouple to heat up and make enough voltage to energize the magnet inside the valve I'm holding.......or, like on yours, you may turn your dial to "Pilot" and then push it down and hold it until you have a flame, wait 30sec., release it, and then move the dial to the "on" position and then further to set the tempurature number.  Hope that makes some sense.

I'm new to PUP's too, learning as I go and thankful for the help I've received here either directly in questions I've asked, or via archived threads.  There's a ton of knowledge here and people like Wavery and AustinBoston and Mike, make it a great forum.

[mountainrev]

Mountainrev that sure seems strange that yours won't work with the camper "down."  Might be worth finding out what you're loosing and see if you can get it dialed in.  Thermocouple's make their own voltage as they are heated and that voltage energizes a magnet in the safety valve portion of the gas valve (or a seperate safety valve like in my Dometic 2190) and once that magnet is holding the valve open internally, gas flows to the gas burner.

Sorry to hijack the thread.  I agree--it is strange.  I'd love to figure out why my Dometic will not light when it's popped down.  But I don't know where to start.  What should I look for?  Does anyone else out there have a similar issue?  Is this a safety feature which Viking built in?  Or is this a problem unique to my camper?

[AustinBoston]

Sorry to hijack the thread.  I agree--it is strange.  I'd love to figure out why my Dometic will not light when it's popped down.  But I don't know where to start.  What should I look for?  Does anyone else out there have a similar issue?  Is this a safety feature which Viking built in?  Or is this a problem unique to my camper?

How many times have you tried it?  I know the ease of lighting varies a lot with our fridge, and sometimes it takes a good 5-10 minutes (and some mumbled curs...incantations).   :mad:  But it acts like this in both the up and down position.

Try holding the gas button down for several minutes, then waiting a minute with the button off, then lighting normally.  Sometimes our gas lines get filled with air (which does not burn) from just sitting there.

Something else to try would be to pop up, light it, and close it.  See if it stays lit.  If it does, then turn it off for 15 minutes, then try lighting it.

My suspicion is that you just have a tempramental burner, and it just happened by chance to only act up when popped down, and there isn't really anything different about popped up and popped down.  Doing what I've suggested would prove me wrong (something that's never happpened before :book: ).

Austin

[wavery]

Sorry to hijack the thread.  I agree--it is strange.  I'd love to figure out why my Dometic will not light when it's popped down.  But I don't know where to start.  What should I look for?  Does anyone else out there have a similar issue?  Is this a safety feature which Viking built in?  Or is this a problem unique to my camper?

HMMMMMMMMMMMMMMMM!!! I doubt that it would be any kind of "Safety Device". They would have to build in some sort of shut off valve in the gas system (added expense). I just can't imagine how that (in itself) would be "Safe". Seems to me like it may just be another thing to go wrong and could indeed add more liability and warranty problems than it may prevent. I just can't see the manufacturer going to that expense when it appears to be a little risky.

[austinado16]

I say pull up a stool with some wrenches in hand, pop the louvered bottom door up (or take it off), and see if you have gas flow (PUP closed).  That's all it needs to work.......gas, and for you to light the flame and hold down the safety until the thermocouple gets hot enough to do it for you.

You're not going to blow yourself up.  If you can't get it lit at the burner, even after taking long enough to purge the air, then loosen a gas fitting there in the fridge compartment and then operate the gas valve and see if you hear hissing or smell propane.  If you do, great, you know you've got gas.....so to speak.

If not, back track up the system and find out why.

[AustinBoston]

HMMMMMMMMMMMMMMMM!!! I doubt that it would be any kind of "Safety Device". They would have to build in some sort of shut off valve in the gas system (added expense).

Actually, all they would need is a switch in the thermocouple (assuming it is a true electro-thermocouple and not an oil-expansion valve*).

Austin

* oil-expansion valve may not be the technically correct term for the device...