400W/100W power outlet: does it dynamically cut off at high speeds?

So I went on a trip this week and put my fridge in the back under the tonneau plugged into the outlet. I know it switches from 400W to 100W when I start moving (not sure why since I have the upgraded tow package alternator) but it seems to also turn off completely when I'm running at speeds over 60-70MPH and won't turn back on!?

I looked down briefly (75MPH lol) and saw the light(s) off on the button so I pushed it in and the 100W light stayed on for a second or two then went back out. So I pulled over and tried again at idle in neutral, and it turned on and stayed and both 400/100 lights were lit. So I got back into traffic and watched as it switched to the 100W light and stayed on for a few miles and when I went fast to pass and go up a hill that light went out again.

What's happening? Do I need to do that 400W-always-on-mod?
Here are the specs on the fridge, it's pretty light on power: https://www.massimomotor.com/MASSIMO-E-KOOLER

 

I have a similar fridge with a very low power Japanese motor. I think it should run without any issues. Something is fucky with the inverter system because I get the same behaviour as you.
I plan to tear out the inverter outlet in the bed and replace it with a DC power panel fed by 10 gauge wires. I will just buy an inverter and plug it in.

 

I don't know about all that, but I know there is a 400W anytime mod that could address that.

 

When it's in drive it's 100W, every other time it's 400W (with ignition on and switch turned on)

 

That skimpy power quote for the fridge probably isn't the startup power draw. If you have a killawatt meter, it will show you what is really happening. My guess is your speed was merely coincidental as typically higher revs means higher alternator output. Anyhoo the 400 W anytime mod is simple and easy to do, and will allow you to run another device.

 

I have an Engel fridge which has a so-called "swing motor" that is pretty much the most electrically efficient out there.

The startup current is between 15 and 30 Amps, and the steady state current is around 5 Amps.

The fridge starts fine and it *should* continue to run in 100 Watt mode when the truck starts moving.

Sadly, what I think is happening is that when the inverter switches from 400 W mode to 100 W mode, it interrupts the power to the fridge. This is why the protection trips.

 

The compressor "cycles" while it's running just like the A/C system in the truck except the motor turns on and off instead of the clutch doing the work.

100W at 12V is roughly 8A so if the comp "cycles" while in 100W mode it trips the safety and shuts off.

400W @ 12V is roughly 33A, do the 400W anytime mod and you're good to go.

The Fridge Electronics are more efficient running on 12V so a 12V outlet in the bed would be ideal. ARB makes a kit that's reasonably priced and saves the headache of building one.

 

Good to know about your fridge. But, the OP's condition is already at 100w when failure occurs. That is if my reading comprehension is intact. He is associating it with increase in vehicle speed, which I find doubtful. His specific fridge, regardless of brand/model maybe pulling more for whatever reason. Confirming it off vehicle can be helpful or he can just do the mod and be rid of us.

 

So I don't want to be "that guy," but why run it through the inverter at all? Is it just for convenience of the plug in the back? I bet all your problems would go away if you ran it from the 12v DC/cigarette lighter outlet. (from the product description, it sounds like direct DC power is an option) If you need it in the back/bed, just extend the cable a bit!

 

I'm not sure how long those cables are, but what's your solution for routing the cord from the bed into the cab?

 

First I would try the rear window, and if I wasn't happy, I'd just carefully run it out one of the rear doors (just to make sure it doesn't get pinched/cut). It's kind of low-class/temporary solution, but with a little bit of playing around, and maybe some painters tape in hidden spots, you wouldn't even notice it if someone didn't point it out. It's the kind of thing I might do for the occasional camping trip! Not like a permanent mod type of thing. But good enough for several weekends a year...

edit: the cable for my magnetic antennas is much thicker than a typical DC power cable, and it doesn't interfere with door opening/closing when I'm using it. So that's what I'd do.

edit: if it was something I'd do all the time, I'd look into a mod to put a DC outlet in the bed [before the inverter]. Theoretically it sounds super simple.

 

Simpler to do the mod.

 

Sorry if it wasn't clear. My fridge has a Sawafuji swing motor. Lowest steady state, and also very low startup transient, current, of pretty much anything out there.

If the inverter system cannot run my fridge, it would be hard to see how it could run any fridge.

Highly recommend replacing the inverter outlet in the bed with an Anderson Powerpole setup, fed by 10 gauge wires or similar. Run the fridge off DC to eliminate conversion loss.

 

I run a fridge and charge a lithium solar battery off my inverter for months on the road. Did the mod shortly after purchasing my truck and haven't had a problem. Don't know why for the purpose of running a fridge you have to do all that stuff when Toyota did all the work already. The mod is so simple. Basically a no brainer that fits me perfectly.

 

Appreciate the thoughts. I will look into the 400W anytime mod. I also have a Jackery 500W power supply that I could plug into the bed outlet and plug the fridge into the Jackery. That would probably avoid any sudden current pulls that cause the output to shut off. Maybe also an ammeter inline with the bed outlet in the cab so I can monitor the current draw...

 

That's how I ended up doing it. The Jackery easily keeps everything running and the bed outlet will keep it topped up, when I remember to hit the button. Just strap those things down in the bed so plugs don't get broken

 

I've heard people say it needs to be 12V DC, unless that's what the cig lighter is
Problem with automotive cig lighter ports (typically) is popping the fuse every 5 seconds

I know of the 400w anytime harness mod - is that not necessary?

I see Amazon has for $15 a harness that clips directly onto the battery, running a cig lighter port
so *not* using an inverter

pretty much I'm researching trying to run a

$761 Dometic CFX3 35 Portable Refrigerator and Freezer - 36L - Powered by AC/DC or Solar Portable Refrigerator, Smokey Gray

Dometic CFX3 35, and Jackery (still trying to figure out which is best, maybe 1000)
have not figured out solar jet

^if going that route, is it really as simple as just plugging the battery (in this case Jackery) into cig lighter while idling or driving?

If this works, it sounds good...
Easier to find a home for stuff on the side secured in the bed, than interior cab on seats trying to get enough airflow