Carthago CBE Issues when switching from 240V to 12V

[pk-carthago]

Hi Everyone - When we switch from 240V to 12V our CBE PC320-CA display switches off and then goes into a perpetual malfunction loop with the background light flashing, this can only be fixed by plugging in the EHU. Occasionally, it has flipped over from 240/12V gracefully and we can operate the lights/water pumps/tv ok but if we activate the step this triggers the CBE display to malfunction. The same issue occurs if we attempt to operate the E&P levelling system which I've now disconnected to stop a continuous beep. I've checked the breakers, fuses, leisure battery voltage level, battery charger and all appear to be fine. Before I book an Auto-Electrician to diagnose does anyone have any thoughts on what the issue might be? Any help much appreciated.

2015 Carthago Compact-Line C138

 

[Vansflyer]

Have you checked the battery isolator switch is turned to "on"? Sounds like a lack of constant 12v power to the control unit. Also worth checking the B1 and B2 connections to confirm both are getting 12v without EHU. E&P should only be connected to the cab battery so that is a weird one as well. If you can use a multi meter then start at the leisure battery and work forward, worth bearing in mind that if hab battery is original it may be very tired by now. It can give a voltage reading but once under load it falls over.. Good luck.

 

[Pausim]

In some ways it suggests you have a depleted battery or a poor battery connection. You say you have checked the battery voltage but this can be misleading if the battery has become sulphated. A sulphated battery can still reach full voltage but will drop off rapidly as soon as any heavy load is applied. If you can check the voltage at the same time as operating the step you could check check to see if the voltage suddenly dies away.

 

[pk-carthago]

Have you checked the battery isolator switch is turned to "on"? Sounds like a lack of constant 12v power to the control unit. Also worth checking the B1 and B2 connections to confirm both are getting 12v without EHU. E&P should only be connected to the cab battery so that is a weird one as well. If you can use a multi meter then start at the leisure battery and work forward, worth bearing in mind that if hab battery is original it may be very tired by now. It can give a voltage reading but once under load it falls over.. Good luck.

In some ways it suggests you have a depleted battery or a poor battery connection. You say you have checked the battery voltage but this can be misleading if the battery has become sulphated. A sulphated battery can still reach full voltage but will drop off rapidly as soon as any heavy load is applied. If you can check the voltage at the same time as operating the step you could check check to see if the voltage suddenly dies away.

Thank you both for the advice it's much appreciated. We have noticed the voltage suddenly drops on the meter when the E&P levelling system is activated whilst also triggering the CBE display to switch off and start flashing; I suspect you're both right about the battery failing under load. I've checked the E&P system and it's cabled to take power off the the leisure battery, all the manuals suggest it should be powered off the car battery, but that might explain why we've not needed to engage the ignition when activating the levelling system. I'm hoping changing the battery will fix the issue but will call E&P first and run this by them.

 

[Vansflyer]

Thank you both for the advice it's much appreciated. We have noticed the voltage suddenly drops on the meter when the E&P levelling system is activated whilst also triggering the CBE display to switch off and start flashing; I suspect you're both right about the battery failing under load. I've checked the E&P system and it's cabled to take power off the the leisure battery, all the manuals suggest it should be powered off the car battery, but that might explain why we've not needed to engage the ignition when activating the levelling system. I'm hoping changing the battery will fix the issue but will call E&P first and run this by them.

Maybe you are closer to finding a solution now you know the E&P is connected wrong. The jacks can whack a load of current out of the system when operating, I don't turn the engine off now till we are level just to spare the battery a heavy load. Easy enough to test your leisure battery if you have a meter? The E&P should need rewiring going forward as it really should only work with ignition and handbrake on. A new LB isn't silly money so a cheapish fix if buggered... technical term Let us know how you get on.

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[Pausim]

Easy enough to test your leisure battery if you have a meter?

Voltage alone will not show if the battery has lost its capacity. A 90% defective lead acid battery can still show a full voltage because the active 10% behaves like a small battery. It just can’t cope with the normal demands.

 

[Vansflyer]

Voltage alone will not show if the battery has lost its capacity. A 90% defective lead acid battery can still show a full voltage because the active 10% behaves like a small battery. It just can’t cope with the normal demands.

Ta, I am aware of that but don't wish to overload the OP with too much tech info. A voltage reading is always the start of the diagnostics but start loading up the current drain and it becomes fairly obvious how it is performing. Cheers

 

[cyberyacht]

Maybe you are closer to finding a solution now you know the E&P is connected wrong. The jacks can whack a load of current out of the system when operating, I don't turn the engine off now till we are level just to spare the battery a heavy load. Easy enough to test your leisure battery if you have a meter? The E&P should need rewiring going forward as it really should only work with ignition and handbrake on. A new LB isn't silly money so a cheapish fix if buggered... technical term Let us know how you get on.

How does that work? I thought rams auto retracted when ignition is turned on.

 

[Vansflyer]

How does that work? I thought rams auto retracted when ignition is turned on.

Nope, ignition needs to be on and handbrake applied for the rams to extend. Ignition on and putting handbrake off causes them to retract automatically.
That is the standard set up as far as I am aware for E&P systems.

 

[peterc10]

The recognised experts for E&P jacks are SAP in Doncaster. Give them a ring and ask for Mick. He will be able tell you what is wrong and fix it for you. I suspect the problem is that they should be using the engine battery rather than the habitation battery. That is what our E&P jacks use.

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