Dometic AES III Fridges

Spydermann · Senior Member

Dometic AES III Fridges

PeterD · Guru

What's your query?

Spydermann · Senior Member

My caravan manual, Dometic manual, caravan dealer and Dometic dealer all seem to vary in their opinions as to how the AES works. So I'm trying to sort out how it should really work. Given that you should not travel with gas on, I'm thinking the AES to gas (when 12v car or 240vac not available) is a waste of time and doesn't appear to work in any case. Works fine manually. Still awaiting clarification on a few points from a few people.

As someone pointed out in another post, dealers are not always up-to-date on caravan equipment and I can see their problem. Low volume and regular change of equipment, unlike cars. Also, with warranty on some items not carried out by the van dealer, it can be messy trying to find out who is responsible: van dealer or equipment dealer.

dorian · Guru

AIUI, the seller (in your case the dealer) is responsible for warranty work, even if he has to organise Dometic to do it. Don't let him fob you off.

PeterD · Guru

Spydermann wrote:
Given that you should not travel with gas on, I'm thinking the AES to gas (when 12v car or 240vac not available) is a waste of time and doesn't appear to work in any case. Works fine manually. Still awaiting clarification on a few points from a few people.

I would take note of the operating manual. After all it is written around how the manufacturer designed the fridge. It's a pity you did not include the model number of your fridge. If your fridge is not working properly on gas when switches to auto then they have stuffed up the installation. I have explanations of at least three models of Dometic AES controller. However they all basically work the same. There are three 12 V inputs to the back of the fridge. There is heavy 12 V input for the fridge element (same as all other fridges) that comes directly from the tugs alternator/battery. It should not be connected directly to the house battery. In addition to that there is a low current input from the house battery to power the AES logic board. The third input is a signal from the tug to indicate that the alternator is charging or the ignition switch is in the run position. (this third signal wire is designed to run to the ignition circuit in the tug but id you are using a voltage sensitive relay or ignition controlled relay to disconnect the 12 V supply to the fridge element some installers will wire the control wire to the element positive wire.)

The fridge will not work as designed if any of these connections has been incorrectly wired. If the house battery supply is not getting to the logic board is can not operate.. If the mains power is available the logic will switch the fridge to work off it. If there is battery supply from the tug and the signal wire is livened up (ignition switched on) then the logic board will power the fridge from the tug. If the signal on the ignition signal wire is cut then the logic board will light up the gas, the gas ignition spark is powered by the house battery.

As far as warranty work goes it's up to the agent to sort out the fridge wiring. Do you have a multi meter and know how to use it? If you give us the fridge model number we can tell you where to find all the connections.

-- Edited by PeterD on Tuesday 17th of November 2015 10:28:27 PM

Spydermann · Senior Member

dorian wrote:
AIUI, the seller (in your case the dealer) is responsible for warranty work, even if he has to organise Dometic to do it. Don't let him fob you off.

It's not quite that simple. When you get your new van you get a heap of manuals and manufactures warranty forms for equipment (radio, microwave). Should one of these items fail, one needs to contact whoever holds the warranty on that item. However, if the fault is vague then you have the warranty shop saying it's an assembly issue and the assembly people saying it's a product problem. It's even worse when there are two problems, one an assembly and one a manufacturing. No one wants to go first. However, I think I may have it licked but if it's still dodgy I have the option of getting my next service at a nearby van shop who is also a Dometic dealer.

Spydermann · Senior Member

PeterD.

Fridge is a Dometic AES III RM2355. I have the wiring manual. I also have the van manual and the transformer manual. There is a bit of a conflict on what each manual is saying which I hope I have finally sorted out this morning. I just spent the morning with my multi-meter over everything so I can map out the entire 240v and 12v circuits. The primary reason for todays work is I'm hooking up a solar panel and Anderson plug and find out what cables are coming to/from where so I can put the solar panel wire in the most suitable channel back to the a-frame.

KFT · Guru

The AES fridges have a 15 minute delay before the gas will light automatically.

you can force it to light straight away by turning the AES function off.

The delay is to allow safe refueling at a servo.

Does that help or are you having other issues?

frank

Spydermann · Senior Member

My fridge was trying to start immediately when either the 12v from the tug or the 240v from the mains was disconnected. Hence the issue putting fuel in that has been noted. Supposed to have had a 30 min delay put in last week for when the 12v from the tug stops. However this is not working. I can force the gas to start which actually I do not mind as I prefer to have a bit of control to when the spark happens. The fridge not starting other than on manual was happening before I got the 30 minute delay put in. The delay was an van assembly problem, the other not sure (gas only on manual) but I can live with that.

PeterD · Guru

Spydermann wrote:
PeterD.

Fridge is a Dometic AES III RM2355. I have the wiring manual.

Sorry I'm a bit slow getting back but I have been chasing the source of this paper - AES REFRIGERATOR WIRING - It has information that will be of interest to you and everyone else with an AES fridge.