Roller Team 600G 2007 model Thetford N145 fridge issues

[Pidea]

Last week we went away in out 2007 AutoRoller 600G and, despite a few niggles (to be documented later !) we had a good time.

Our only really major problem was that the Thetford N145 fridge wouldn't stay cold when running on 12 volts but ran quite happily on mains or gas. Whenever it operated on 12 volts the blue LED would flash and the spanner symbol appeared on the display. I'm aware that it only operates on 12 volts whilst the engine is on so that wasn't the issue as we were driving at the time so there's another issue.

From Googling it appears that it could be a power supply issue. Having found the installation manual for the fridge online I'll check the wiring tomorrow but the other possible cause is the 12 volt heater has failed. Looking at these online it appears that they don't have a very long cable on them:

Therford Heater DC - N145/150 Models | Caravan Fridges | Titan

Genuine Thetford spare parts supplied and fitted by Titan for motohome and caravan fridges, Order a replacement Thetford Heater DC for N145/150 series today.

titanmotorhomesandcaravans.com

So my question is: is the 12 volt heater located at the bottom of the fridge where it might be accessible from the lower fridge vent or is it higher up and therefore out of reach which would mean removing the fridge (something that I'm loathed to do).

Thanks in advance !

 

[DandG5515]

We have a RT600 fridge will only run 12v with engine running as wired to alternator. Always leave on auto, then it selects hookup 1st then 12v then gas. Depending which is available. Can only clear fault “spanner” by switching off and on,

 

[bigtwin]

The heating elements are usually accessible from the bottom fridge vent.

Ian

 

[suavecarve]

We have a RT600 fridge will only run 12v with engine running as wired to alternator. Always leave on auto, then it selects hookup 1st then 12v then gas. Depending which is available. Can only clear fault “spanner” by switching off and on,

As per above

 

[DandG5515]

Sorry didn’t read full post before answering, did you manually select 12v or by auto?

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[suavecarve]

I ve just re read and may be confused as well.
Are you using the 12 volt option when the engine is off expecting the leisure battery to operating ? If that is the case then change the setting to 240 or gas upon stopping. (or just put on auto and forget it)

 

[Spanner]

It’s worth checking for a bad connection on the 12 volt wiring, ours had a faulty connection in the multi plug which was easy to access and repair from the lower vent

 

[Pidea]

Just to clarify peoples confusion .... as I stated originally the fridge does not cool on 12 volts whilst driving (i.e. with the engine on). I'm not expecting it to.

However, I switch it to battery mode before starting the engine (and see the blue flashing LED) and once the engine is running the blue LED remains flashing. I would expect it to flash whilst the engine is off but to stop flashing once the engine is on. Perhaps that's because I didn't leave it in Auto mode but manually switched to battery mode ?

I'll go over to where we store it later and will check again.

 

[DandG5515]

Hi error occurs because you switch before starting engine. Run on gas auto first then start engine and should switch without touching it. Likewise engine stop auto back to gas. I travel with gas on for this reason.

 

[DandG5515]

Once flashing error fridge does not reset itself.

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[Pidea]

I thought it was illegal to travel with the gas on ?

 

[DandG5515]

Don't know, I have Auto shut-off on refillable bottle if impacted. However I would recommend starting engine then switching bottle off to save fridge erroring. Or switch fridge off isolate gas, start engine then switch fridge back on.

 

[Pidea]

OK, just popped over to the motorhome and started it up. I then turned on the fridge and it defaulted to gas (even though the gas supply was turned off). It didn't offer to run off of the battery despite the engine running.

Manually switching it to battery mode resulted in the same problem as before, namely the flashing blue LED and spanner symbol on the display so it could be an issue with the 12 v supply to the fridge or the heater element.

 

[TerryL]

Is there a code on the fridge panel when the flashing blue LED is on? The 12v system isn't really expected to cool the fridge down just hold it at whatever temperature it was when switched to 12v. But if the element has failed, which isn't uncommon on a fridge that age, a code will tell you. A poor connection, if there is any juice at all, will show a different fault. Check your fridge handbook for codes.

If there is an error present on the 12v system the auto selector will not go to it and instead go to the default, which is usually 240v electric, unless again there is none available.

Changing the element is not difficult provided you can get at it, but I had to take the fridge out to change mine - it's not as bad as it sounds as long as you take care with all the connections, especially the gas, which you have to disconnect. I've done it a few times for different reasons (one of which was to tighten a screw on the entrance door grab handle!)

As an aside if you select gas, either manually or automatically, the system doesn't care if the gas is on or off. It will run for a short time but then shut down and, believe it or not () show a fault.

 

[DandG5515]

Hi attached fault codes for the fridge 2 looks like faulty heater 10 is no power from engine. I have just put mine in manual 12volt without engine running and came up with spanner 10 on starting the engine it did clear the fault, so I’ve learnt something today. I will try and give you all my ideas in one go to save you going backwards and forwards.

behind the passenger seat is a black box with fuzes in, second one looks like a fridge symbol with a 20amp fuze in. I would check them all with a meter.

with the engine running, on the panel above the hab door press top left button to see engine and domestic battery condition. On engine running both battery packs should be reading 3 green leds. Without engine running they normally drop to 2 leds quickly. I am looking for voltage to be correct from alternator to habitation side. ie have you had any problems of habitation batteries charging while driving?

i have had my 600 from new and have most of the manuals, unfortunately I cannot find a wiring diagram for the fridge.

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[Pidea]

Apologies for the delay - I had to upgrade my account and wait for it to be activated.

Do you definitely have an N145 as there is no code on my screen just a spanner symbol. Perhaps you have a different model fridge ?

 

[DandG5515]

Mine is a year newer so maybe a slight change in display

 

[XxAnthxX]

Check for a 12v D+ signal at the fridge when the engine is running and check the fuse.

Thetfords website contains flow charts for all their models, they also list the resistance for the relevant 12v elements.

On some of the models without a lcd display the Led lights, light up in a sequence that you can read the error code from.

 

[Pidea]

The LCD display looks the same but the panel is slightly different although the buttons are in the same place. My model number is the same as yours though - REFR N145 - N51H06R6A which is odd.

Is there any particular set of button presses that you need in order to get the error code to display ?

 

[Pidea]

Duh ! I assumed that 10 related to the current fridge temperature or something but it's actually the error code (in my defence it's been a loooong day !). I'll pop back over and will see what code I get when the engine is running. Pretty sure that it's the 10 ...

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[TerryL]

Link from Practical Caravan with probable cause.

thetford fridge, 10 spanner fault

Hi all can anyone help me track down a problem, my fridge (2008 swift challenger 540) has always been a bit hit and miss on 12v, I thought I had it sorted with a fuse, but now I have power (13.6v with engine running) both sides of the fuse and yet the fridge is warning me that the engine is not...

forums.practicalcaravan.com

And repair

 

[Pidea]

Hmm ... the plot thickens. The 20 Amp fuse in the fuseholder behind the passenger seat is fine.

Looking inside the bottom vent it's possible to see the wiring that's connected to the fridge. From left to right are the 3 wires for the mains hookup, then the two large diameter wires (red and black) are the supply from the alternator and then two thinner wires to the far right are the low current 12 volt wires to power the fridge light etc.

With the engine off there's 14 volts across the red and black ones and with the engine on there's 14 volts across the red and black ones. Given the error message on the fridge (10 - No engine running signal) I wasn't expecting the 14 volts across the wires with the engine off ....

We do have 2 x 100 Watt solar panels that are connected to the leisure battery via a charge controller but I can't see how that would give us the voltage across the red and black wires. Totally stumped !

 

[DandG5515]

ok mine is very similar but wired by a different money with different coloured cable. 240 on separate con block big red and black permantly 12volt dispite engine on or off. I think orange signal from engine running, purple still need to confirm as low power consumption. Still looking for proper wiring diagram. Will try pm

 

[Pidea]

Thanks - I'm really surprised at the shoddy looking wiring. I thought an amateur had bodged mine but yours looks no different so perhaps that's how they left the factory !

 

[DandG5515]

I’ve been to the autotrail factory and for higher price you still get the same. Ok I am learning as quickly as you, i will try and come back with some more ideas, may be possible to put a switch (link) in to fool the fridge.

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[mitzimad]

Delete

 

[mitzimad]

do you have a relay for þhe fridge or is itintegralwith the fridge

 

[DandG5515]

Ok been busy today installing solar panel, so had a chance to pull van apart.

Duh ! I assumed that 10 related to the current fridge temperature or something but it's actually the error code (in my defence it's been a loooong day !). I'll pop back over and will see what code I get when the engine is running. Pretty sure that it's the 10 ...

Ok been a busy day installing solar. Have given me a chance to have a good look around the van to find anything else. Red to black 12v perminately, purple to black 12v perminate assume low consumption supply. Orange to black only 12volt when engine running. Cannot find where the orange ie signal from engine is connected to. Could go into plc board in box behind passenger seat. Had a tentive look in thier but wired tight and did not want to bugger my van up. I am guessing that were the split charging is controlled from.

I have read on another forum about linking orange with positive feed on another truma to fool the fringe to run on 12v from solar. I suppose that would prove the fringe isn't faulty. Permanent doing that would leave it possible to flatten domestic batteries quickly, and would stop it working correctly on auto. I think I am at the end of my knowledge.

 

[Pidea]

Thanks for the comprehensive post. I've popped over to mine to try and resolve another issue (unsuccessfully) and took a quick look and couldn't see where the wires feed from either. Will have another look when it's not raining so much !

 

[Pidea]

OK, had half an hour so went over to the motorhome to sort out the Fiamma turbo vent which still isn't working. Oddly it only has power when the lighting circuit is on but the voltage is around 10 volts not the 12 volts that I was expecting. With the engine on I get 12 volts.

So ....

I'm wondering if the fridge issue is related in some way, perhaps an earth leak somewhere ? Which might also explain why my non-working reversing light only has about 8 volts across it instead of the expected 12 volts.

Puzzled !

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