Isotherm Refrigerator Saga

I replaced my original 3-way refrigerator last spring with an Isotherm CR130 marine refrigerator.  The old one never worked for more than a few hours and mostly not at all.  I tried everything but to no avail.  After much research, I settled on the Isotherm because of it's excellent reputation for ruggedness, efficiency, and the company standing behind it's products.  It was expensive but I really wanted one that would be reliable and very miserly on the battery usage.


I got it and installed it with little trouble other than the prep for the cavity.  It worked beautifully on a short trip I took at the end of April.  I had it running for a week before I took off in early July so that I could see how it kept the temps in summer temperatures and it worked well, even empty.  My first day out, it worked well and used about 1/3 of my battery allotment overnight while running the inverter and fan.  It is so quiet, I have to put my ear right up to it to hear the compressor at all.  I was really happy with it.

But the second night, it failed.  I woke to the inside temp being about 50F.  Yikes!  I spent the morning pulling the refrigerator to check the connections and make sure everything was solid.  It was.  I had a ridiculous amount of trouble getting the trim I made out because a nut broke and was spinning on the screw with no way to reach it.  I finally just yanked it out forcibly and will have to re-do the trim later. I tested all the connections with my voltmeter and got electricity at all points.  I got out the manual for it and followed its troubleshooting with no luck.

Defeated, I pushed it back in and secured it to make sure it rode ok in the van.  Fortunately, at the last minute, I put the small cooler into the van behind the passenger seat in case I needed more room for things like fruit.  I stopped for a big bag of ice and put it into the cooler and into the produce bin of the refrigerator plus a plastic container in the mid section.  I put the most perishable food into the cooler on top of the ice and the rest on top of the ice in the refrigerator.  It all made it without spoilage even tho the empty air space in the fridge read in the 50's.

Once I got to my sister's house, I emailed the company abut the problem.  In under 24 hours, I got a response with a pdf explaining clearly how to test it and what the results would mean.  Being at my sister's house, I got a small wire to actually bridge the T and C connectors as directed and this time, the compressor came on. (Note to self, put a little extra wire in the toolkit)  That indicated the compressor and fan were ok and the ASU computer unit was at fault.  The Isotherm guy asked me to call him and he thoroughly explained how the unit worked AND how to jury rig it to run it off a manual switch in the meantime.  He said they could test the ASU and get it back to me inside of a week so I had him return it to my sister's house.

Manual switch to run fridge

In the meantime, I got wire, connectors, and a 20 amp auto 12V switch and wired it to the power and bridged the T & C to run it manually.  That worked well.  Having the top more or less open let a lot of hot air into the van so I used a towel to block the heat.  It was also evident at how hot the cavity gets when the temps are 100F.

The ASU tested fine so they sent me a remote switch as that also has a circuit board and could be the fault   It came 2 days after they sent it.  No joy.  It still wouldn't come on.  Defeated again and needing to get back home, I reconnected the manual switch and pushed the fridge back into place, secured it and we went home.  It worked fine.  Most mornings, it had gotten into the mid to low 30s so I turned it off for a while.  It was so hot in the day that running it all the time kept the fridge temps in the low 40s.  That made it so the manual switch was not much bother since I needed it to run most of the time.

Once I got home, the Isotherm guy sent a replacement ASU in case it was at fault even tho it tested fine. Still no joy.  I also got a 8ga wire and connected it directly from the battery to the fridge bypassing all the van wiring and still no joy.

He said to send it to them (by freight on a pallet - $$$) and they would fix it and ship it back.  I would have to pay to ship it down but they would pay to return it.  It cost me $180 to get it in the first place so that is a not insignificant sum.  But what could I do?  It would cost me more in gas just to get it down there.

My aisle in the van is narrow so I have to remove the door and the supports for it that jut out to get it out.  Once I did that and had it sitting in the door, I tipped it back to put the supports back on the bottom and suddenly, my eyes locked on a wire in the back of the inside of the fridge.  There's a telephone wire with a RJ11 jack going to the ASU that controls the thermisters.  The yellow wire was still connected to a blue connector but the black wire was loose.  There are also a red and green wire.  I took a guess and put power back to the ASU and touched the end of the black wire to the connector and voila!  The compressor and fan came on.  The lights on the remote came on as they are supposed to and it started freezing the blue ice pack.

Broken wire inside fridge.  It goes to the back of the blue ice plate.

I sent an email back with a picture of the connector but haven't heard back from the Isotherm guy.  I don't want to spend a couple hundred bucks to ship it if that is all that is wrong.  I need to know if the red and green wires do anything or are just extra because that's how phone wires are made.  I'm confident that I can repair the connection myself but the wire is short so I would prefer a new wire to make the repair.

The connector is too big for the 26ga phone wire side and as it hangs down against the back wall, I'm pretty sure that during movement of the van, something inside the fridge knocked against it and broke the wire.  I found phone connectors that will probably work better for such a tiny wire than the blue barrel connector they used.  I will also cable tie or tape the connection to protect it and keep it up out of the way of the contents.  That seems to be the weak link.

The responsiveness of the company to the problem was stellar except for the silence this week but I suppose my contact could be on vacation.  I did tell him that I'm no longer reliant on the fridge now that I'm back home so the urgency is gone.  I hope they learn from this and make a better protected connection to this in future models.  It is a newly designed refrigerator so their experience is limited with it.

Update on Tuesday morning:  My contact replied.  He had been out with a health problem and will send me a new wire.  The green and red wires are not used so only the black and yellow wires need be connected.  He said the wire had somehow been pulled down as evidenced by the white stuff where it is supposed to be up where the white cable goes thru.  Not sure how that happened but in the interior picture I took of the fridge when I received it, the wire is not dangling down like it is now.  This is a company that stands behind their product and is extremely helpful in correcting any problem.