Propane and towing

[Byron Kinnaman]

This is an old argument. There's lots of things that people do that are somewhat risky and they get away with it for ever. Others don't.
When it comes to some activities it's a good idea to evaluate the risk vs the cost reducing that risk. Towing with the propane running the fridge is one those that also fits the "it only takes once" law. It only takes one time to forget to turn off the propane when fueling for vehicle, maybe you've got away with it a 100 times before. The conditions just right and a loud noise occurs. What's the cost of turning off the propane to further reduce the chances of a loud noise? In my opinion there is no cost, in fact it's less cost of time than running with the propane on. I don't have to get out before I get to the pump and turn the propane off. I don't have pull away from the pump then stop, turn the propane on the re-light the fridge.

Risk vs cost...
Law of once.

[Steve L.]

Originally Posted by sokhapkin

This is a BS. Sorry, can't resist. All vehicles have at least 80-100A alternators, fridge consumes about 10A on 12V.

I agree mostly with Bryon. Dude! It not the size of your alternator it's what you do with it.

There was a move afoot about 10 years ago to take car batteries to 24v because the electrical demands are so great in modern cars. Obviously it died out.

Plus, the capability to generate 100a doesn't mean "all you can use", is being made available to the charge wire in the towing harness. My Flex w/tow package has a 200A alternator and I know for a fact that only about 4 amps is passed to the trailer when my refrig is on DC and drawing ~10a.
(photo of test box in line with the trailer connection.)

I routinely arrive at my campsite with a dead trailer battery after a long trip despite my 200a alternator.

[Byron Kinnaman]

Originally Posted by Steve L.

I agree mostly with Bryon. Dude! It not the size of your alternator it's what you do with it.

There was a move afoot about 10 years ago to take car batteries to 24v because the electrical demands are so great in modern cars. Obviously it died out.

Plus, the capability to generate 100a doesn't mean "all you can use", is being made available to the charge wire in the towing harness. My Flex w/tow package has a 200A alternator and I know for a fact that only about 4 amps is passed to the trailer when my refrig is on DC and drawing ~10a.
(photo of test box in line with the trailer connection.)

I routinely arrive at my campsite with a dead trailer battery after a long trip despite my 200a alternator.

I was quite surprised, I guess I shouldn't have been, when I went to purchase a new battery for my 2005 Dakota with tow package. They checked the current coming from the alternator no trailer, no accessories on, and the truck idling. The truck was using almost 100 amps at that point. It has a 150 amp alternator.
My previous tow was a 1998 Blazer, I managed to get 2 amps to the battery with nothing on in the trailer. As soon as I turned on the fridge I started drawing close to 8 amps out of the battery. Yes I put a meter on to be sure of what was going on.

Steve, they started talking about going to 24volt or even 32 volt systems about 20 to 25 years ago. The amount of copper was getting very hard to handle both weight and the cost of copper. Much of the problem was solved with CAN buss and microprocessors. It still takes a lot of current to run everything but you don't have to run large gauge wires to and from switches as well as power the stuff you need to run.

[Carol H]

My guess would be that the newer the car and the more stuff such as navigation system, blue tooth, tire monitoring, rear DVD, etc etc the more amps the vehicle uses up and the less that is available to go to the trailer. Could be wrong though!

[Bob Miller]

The unanswered question remains: It is not illegal to pull your trailer with the refrigerator ON in any of the 50 states nor, apparently, in the opinion of those states, is it unsafe.

Of course there are local exceptions for tunnels, ferries etc.

But, travelling in fear of every and any possible risk, is like living life on ones knees.

[Joe Romas]

Originally Posted by bob miller

but, travelling in fear of every and any possible risk, is like living life on ones knees.

x2
I can't agree more

[Raz]

Originally Posted by Bob Miller

The unanswered question remains: It is not illegal to pull your trailer with the refrigerator ON in any of the 50 states nor, apparently, in the opinion of those states, is it unsafe.

Of course there are local exceptions for tunnels, ferries etc.

But, travelling in fear of every and any possible risk, is like living life on ones knees.

Seems the people that run the tunnels and ferries don't think it is safe??

[Bob Miller]

Originally Posted by P. Raz

Seems the people that run the tunnels and ferries don't think it is safe??

Just like running your car in a closed garage, it's all about location, location & location. One would think that, should something happen with a leaky or broken LP line in an enclosed space that the consequences could be much greater than just when driving down the road. Again it's all about risk management.

BTW: In those instances ALL of the LP must be OFF and the tank valves closed. It's not the refrigerator flame they are concerned about, it's the entire system.

[Carol H]

Originally Posted by P. Raz

Seems the people that run the tunnels and ferries don't think it is safe??

International marine safety laws require all propane tanks to be shut off when traveling on ferries - big or small ones.

[sokhapkin]

Originally Posted by joe romas

x2
i can't agree more:d

+1.

[Byron Kinnaman]

Same old argument.

[Dan Meyer]

Originally Posted by P. Raz

Seems the people that run the tunnels and ferries don't think it is safe??

That is because propane is heavier than air, and they don't want an accumulation of propane in the low point of the tunnel or hull of a ship.

If using propane while moving was so dangerous, it would have been outlawed as a motor fuel a long time ago.

-- Dan Meyer

[Raz]

Originally Posted by Dan Meyer

That is because propane is heavier than air, and they don't want an accumulation of propane in the low point of the tunnel or hull of a ship.

-- Dan Meyer

good explanation. Raz

[sokhapkin]

Originally Posted by Byron Kinnaman

Same old argument.

Wear. Definitely. They are your life savers in the case of accident, aren't they?

[sokhapkin]

Originally Posted by Carol H

Count yourself amongst the fortunate ones Many here including myself have found that the tugs charge line can not keep up with the 12v consumption of the fridge while towing. True of both the tugs I have used for my current trailer - one with factory tow package and one that had to have the charge line added to it.

Possible reasons for your good fortune is the gage of your charge line and as yours is a newer trailer the fridge may be more conservative on its 12V usage?

I think that the reason of my good fortune is in the wire gauge. Gauge 10 is problem free. I recently purchased used 2013 F150 without towing package, it has tow wiring in the cab, but the wire harness from the cab to the rear of the truck misses tow-related wires (charge line and electric brakes). I added wires myself. The (relatively short) inside cab wiring for charge line is done with 12 or maybe even 14AWG wire! I'm almost sure that tow package wiring from the cab to rear is done with the same wire size. Sure it is not enough to power the fridge and charge the battery.

Let's see how it will work, maybe I will have to replace in-cab charge wire with gauge 10 too.

[The Minimalist]

Originally Posted by sokhapkin

I think that the reason of my good fortune is in the wire gauge. Gauge 10 is problem free. I recently purchased used 2013 F150 without towing package, it has tow wiring in the cab, but the wire harness from the cab to the rear of the truck misses tow-related wires (charge line and electric brakes). I added wires myself. The (relatively short) inside cab wiring for charge line is done with 12 or maybe even 14AWG wire! I'm almost sure that tow package wiring from the cab to rear is done with the same wire size. Sure it is not enough to power the fridge and charge the battery.

Let's see how it will work, maybe I will have to replace in-cab charge wire with gauge 10 too.

Check to see if those wires aren't connected to relays that energize more substantial conductors.

[sokhapkin]

Originally Posted by The Minimalist

Check to see if those wires aren't connected to relays that energize more substantial conductors.

Charge wire is connected to the dedicated relay/fuse in the fuse box in the engine compartment.