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Truma solar charge controller fuse location

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The roof mounted panel on my series 3 Unicorn Cadiz isn't charging the leisure battery 

The Truma solar controller is set up correctly for a wet lead acid battery but on checking the voltage from the panel with a multimeter it’s not showing 18+ volts which it should in sunlight 

I’m guessing there should be a fuse between the panel and the controller but I cannot locate it 

incidentally the connection from the battery at the controller shows 12.5volts 

and the connection at controller from the solar panel also shows 12.5 volts even in bright sunlight 

Edited by N&L

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Try disconnecting one panel wire from the controller, them measure the panel volts. If the open circuit volts are 18v plus, it’s probably the charge controller that’s failed

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I had the same issue. No voltage showing at the input to the controller. There is no fuse.

On the roof under the panel there are two push connectors between the solar panel output wires and the connection to the controller.  Disconnecting and cleaning these solved the problem.

If under warranty get the dealer to check - they should be aware of this issue.

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7 hours ago, CliveB said:

I had the same issue. No voltage showing at the input to the controller. There is no fuse.

On the roof under the panel there are two push connectors between the solar panel output wires and the connection to the controller.  Disconnecting and cleaning these solved the problem.

If under warranty get the dealer to check - they should be aware of this issue.

Ok I’ve ascertained that there is a good voltage from the panel but the feed from the solar controller to the battery has an issue 

checked the the 12 volt fuses in the box under the fridge but cannot see anything marked up as solar panel

is there a separate fuse between the solar regulator and the battery and if so where would it be

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Bailey fit a fuse in the wring loom which is located in the rear bed box, taped into the loom close to floor by the side of the fridge. You have to feel around for it as it quite tightly taped in

 

Check that it hasn't become dislodge with stuff being shoved in there although I'd suspect that if the fuse wasn't present (dislodged or blown) then you wouldn't be measuring 12.5 at the controller terminals.

 

How are you determining that the panel isn't charging?. Is the controller light flashing? Have you checked the current from the controller as well as the voltage across the terminals. Perhaps you battery is knackered if it's not being charged

Edited by matelodave
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40 minutes ago, matelodave said:

Bailey fit a fuse in the wring loom which is located in the rear bed box, taped into the loom close to floor by the side of the fridge. You have to feel around for it as it quite tightly taped in

 

Check that it hasn't become dislodge with stuff being shoved in there although I'd suspect that if the fuse wasn't present (dislodged or blown) then you wouldn't be measuring 12.5 at the controller terminals.

 

How are you determining that the panel isn't charging?. Is the controller light flashing? Have you checked the current from the controller as well as the voltage across the terminals. Perhaps you battery is knackered if it's not being charged

I have checked the voltage from the panel with a multi meter and it’s showing 18 + volts so ther is power getting to the charge controller but no 12 volt from charge controller to battery 

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The fuse is in the bed box adjacent to the fridge.

 

It is bundled up in a load of wires at the base of the fridge and not easy to see,it is blue in colour.

 

Ian

Edited by Tandem Man
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1 hour ago, Tandem Man said:

The fuse is in the bed box adjacent to the fridge.

 

It is bundled up in a load of wires at the base of the fridge and not easy to see,it is blue in colour.

 

Ian

I found it and was very awkward to get to but

the fuse had blown so I replaced it with the correct 15 amp fuse 

The Solar panel is producing 18+ volts I disconnected the the feed to truma solar controller and put the multimeter on the 

+ & - minus cables so I know the panel is functioning correctly 

Now that the fuse is replaced ( my fault it blew as I let the wires touch ) we’re getting 13.8 volts showing at the controller which would be correct because we’re connected to EHU 

But if disconnect the mains electricity from the van both the feed coming from the solar panel to the controller and feed from controller to the battery show the same voltage about 12.9 volts 

Even bright sunlight 

Earlier today I disconnected the EHU and deliberately let the battery partially discharge down to 12.6 volts  and after switching everything of and you would expect the solar panel to start charging in sunlight but the voltage remained the same even after 5 hours of bright sunny conditions which would suggest there is fault with the solar controller 

 

 

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There really isn't anything else you can do now except replace the controller or investigate getting it repaired.

 

I dont know whether Truma have a repair or replacement system which might work out cheaper than just replacing it but there are plenty of controllers available on t'interweb

 

I'm sure that there will be plenty of recommendations from others on a suitable replacement if you dont want to replace it with another Truma controller.

 

Have a shufti here https://www.photonicuniverse.com/en/catalog/list/category/solar-controller there's at least one that looks suspiciously like the TRuma unit and significantly less cost. MorningStar & Victron are also well regarded

Edited by matelodave
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1 hour ago, matelodave said:

There really isn't anything else you can do now except replace the controller or investigate getting it repaired.

 

I dont know whether Truma have a repair or replacement system which might work out cheaper than just replacing it but there are plenty of controllers available on t'interweb

 

I'm sure that there will be plenty of recommendations from others on a suitable replacement if you dont want to replace it with another Truma controller.

 

Have a shufti here https://www.photonicuniverse.com/en/catalog/list/category/solar-controller there's at least one that looks suspiciously like the TRuma unit and significantly less cost. MorningStar & Victron are also well regarded

Thanks for your input Dave it’s been helpful 

I’ll replace it with a Victron PWM as I already have one fitted to my motorhome and it works well

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