Troubleshooting an onboard fridge and freezer - where to start

[Bowdrie]

With adequate voltage, and absent obvious physical damage to either the condensing unit or the evaporator, the most common failure mode is the controller.

[Enyar]

Originally Posted by RaymondR

Digital multimeters are not the best tools for trouble shooting refrigerator problems. The old style analog give a much better indication of what is occurring with the compressor motor.

We used to have a couple of really good refrigeration professionals on the forum who could be relied on to give excellent advice. Unfortunately they appear to have been oppressed into remaining silent these days.

I was able to find some LED lights in my pile of junk. I will try again with that. I also have some 6 gauge wire that I will run directly from the battery to test. If that's not enough power then I'll try buying a new controller.

Originally Posted by cr180

Have had a similar problem (maybe the same problem) with a Secop (danfoss) compressor. They are very voltage sensitive. The voltage measured when the compressor is not running can be normal but drops too much when compressor and fan try to start. The cause can be a poor connection anywhere in the circuit including the feed to main breaker on distribution panel. I solved my problem by running a direct feed including fuse from the battery to the refrig terminal block with #12 wire.

Thanks, I will try a new feed and see what happens.

Originally Posted by Bowdrie

With adequate voltage, and absent obvious physical damage to either the condensing unit or the evaporator, the most common failure mode is the controller.

Is there a place that rebuilds them or should I just replace it at around $250?

[Eder]

mis posted

[Eder]

OK heres what I was looking for
Some good guides that have helped me fix my own 2 frigoboat systems...
Hope it helps


https://www.coastalclimatecontrol.co...roubleshooting

[Rocinante33]

I just went through this myself…..condolences.

I think I traced mine to a bad thermostat, but the thermostat showed continuity at every setting.

I set up a jumper on the ‘brain box’ (from T to C, which bypasses the thermostat) which allowed the compressor to kick on. Weirdly, the thermostat checks out on the multimeter, and when I tried to bypass the thermostat itself, it didn’t work. But bypass it at the brain box and the compressor kicks in and runs like a champ.

Small amounts of corrosion can produce near infinite resistance I’m told.

I found this from a guy Jacob to be very, very helpful. There are only so many moving parts on a fridge, but I’m afraid you either work through them one by one, or you pay somebody a couple of hundred dollars an hour to do the same thing.

The only thing you really can’t do yourself is check the gas pressure. (Or at least I couldn’t do…..it was, of course perfect.) But that only cost me a 12 pack and a day to have an hvac guy check it for me.

Adler/Barbour Troubleshooting (and Waeco 50, 80, and 90 series)

Best of luck, but at least this problem has cold beer waiting at the end of it!

[Enyar]

Well lesson learned. You can't use a digital multimeter to pull the code. Previously thought I was getting 1 flash. When tested with the LED I am clearly getting 3 flashes. Time for a rebuild I guess?

[Eder]

Three Flashes–Compressor non start–Very common
Compressor overloaded and unable to start. Most often associated with a system shutdown followed byanimmediate
re-*‐start attempt whilerefrigerantpressuredifferentialin systemisstill high. Typically, systemwill eventuallyre-*‐start
unaided. Often associated withare-*‐start attempt after a low voltage failure. May also be due to a warm start-*‐up in hot
conditions, especiallywithair-*‐cooled systems, where pre-*‐cooling the box with ice and setting compressor to run at
slowest speed are recommended


Compressor most likely is fine.
https://www.coastalclimatecontrol.com/component/edocman/232-so-what-makes-you-think-your-compressor-is-bad/viewdocument/232?Itemid=0

[Rocinante33]

Originally Posted by Enyar

Well lesson learned. You can't use a digital multimeter to pull the code. Previously thought I was getting 1 flash. When tested with the LED I am clearly getting 3 flashes. Time for a rebuild I guess?

How are you using the multimeter to test? At the power connection to the ‘brain box/‘

Do I understand you to be saying that your box is showing one flash but should be showing 3?

I’m at an impasse now. The thermostat restored the fridge as long as the shore power is hooked up or the engine is running

On battery only, it starts flashing after a couple hours even though batts are new and passed soc charge. It will do this even under midday sun when the panels are pushing 14.5 volts and the system tests out at 12.5-12.7 at every point I try.

I’m pretty frustrated now. Not sure what to try next

[Enyar]

Originally Posted by Eder

Three Flashes–Compressor non start–Very common
Compressor overloaded and unable to start. Most often associated with a system shutdown followed byanimmediate
re-*‐start attempt whilerefrigerantpressuredifferentialin systemisstill high. Typically, systemwill eventuallyre-*‐start
unaided. Often associated withare-*‐start attempt after a low voltage failure. May also be due to a warm start-*‐up in hot
conditions, especiallywithair-*‐cooled systems, where pre-*‐cooling the box with ice and setting compressor to run at
slowest speed are recommended


Compressor most likely is fine.
https://www.coastalclimatecontrol.com/component/edocman/232-so-what-makes-you-think-your-compressor-is-bad/viewdocument/232?Itemid=0

Should I replace the controller or try pre chilling the box?

Stupid question, what setting on the thermostat is slower speed? It's not clear if higher is higher temp or higher cooling.

[Enyar]

Originally Posted by Rocinante33

How are you using the multimeter to test? At the power connection to the ‘brain box/‘

Do I understand you to be saying that your box is showing one flash but should be showing 3?

I’m at an impasse now. The thermostat restored the fridge as long as the shore power is hooked up or the engine is running

On battery only, it starts flashing after a couple hours even though batts are new and passed soc charge. It will do this even under midday sun when the panels are pushing 14.5 volts and the system tests out at 12.5-12.7 at every point I try.

I’m pretty frustrated now. Not sure what to try next

No I was trying to say that with the digital multi meter I thought I was only getting one flash. What I think actually was happening is the pulses are so short that my multimeter was only picking up one flash (its digital) but now that I have an LED light on it it's very clearly showing 3 flashes.

[Enyar]

Originally Posted by Eder

Three Flashes–Compressor non start–Very common
Compressor overloaded and unable to start. Most often associated with a system shutdown followed byanimmediate
re-*‐start attempt whilerefrigerantpressuredifferentialin systemisstill high. Typically, systemwill eventuallyre-*‐start
unaided. Often associated withare-*‐start attempt after a low voltage failure. May also be due to a warm start-*‐up in hot
conditions, especiallywithair-*‐cooled systems, where pre-*‐cooling the box with ice and setting compressor to run at
slowest speed are recommended


Compressor most likely is fine.
https://www.coastalclimatecontrol.com/component/edocman/232-so-what-makes-you-think-your-compressor-is-bad/viewdocument/232?Itemid=0

It should be noted that the system has been off for months now so the system restarting unaided isn't happening.

Another stupid question. What should I be doing with the fridge breaker when unhooking from shore power or starting the engine? I was reading that the thing that kills these controllers is voltage spikes from an alternator but im not sure the proper way of how or when I should cut power to this thing. Should I just turn it off when starting or stopping the motor?