Fridge trips when the engine is running. Over voltage?

[pjm-84]

Fridge works fine on EHU or battery but now constantly trips when the vehicle is running.

Having switched back to the voltage display on the Control Unit, the only common item to note is that its showing 14.6 volts and an 0.2amp charge. At this point the fridge will trip.

Having been on EHU for the past 40hrs the batteries are fully charged so I wouldn't have thought fully charged batteries would still charge at this rate. Voltage reads 12.7 on the display when the engine is off but will shortly be going out to check with a voltage meter

 

[sidepod]

That’s a new one!

Hook up the voltmeter at the fridge connection and then start the engine. See if you loose 12v supply.

 

[pjm-84]

Nope. Fine. 12.37 (batt) vs 12.39 (running).

Volt meter and Control unit display pretty close. I think the CU was 0.1 more than the meter.

Its been on battery for a few hours. Just started and ran the vehicle and fine for 10mins, although still a negative draw (didn't appear to be charging on tick over). Just put the fridge on max at 8pm. At 9pm 12.6v and 90%. Now added the internal lights and will check again at 10pm.

Roof works on main battery????. However there was quite a draw showing on the display when the roof was up.

 

[WelshGas]

Nope. Fine. 12.37 (batt) vs 12.39 (running).

Volt meter and Control unit display pretty close. I think the CU was 0.1 more than the meter.

Its been on battery for a few hours. Just started and ran the vehicle and fine for 10mins, although still a negative draw (didn't appear to be charging on tick over). Just put the fridge on max at 8pm. At 9pm 12.6v and 90%. Now added the internal lights and will check again at 10pm.

Roof works on main battery. However there was quite a draw showing on the display when the roof was up.

What do you mean by “ Main “ Battery?

 

[pjm-84]

Vehicle battery rather leisure.

 

[WelshGas]

Vehicle battery rather leisure.

Well unless your vehicle is different to mine. The Roof Hydraulic Pump is powered from the Leisure Batteries. The Ignition has to be ON as a safety precaution to prevent accidental use . Actual power comes from the Leisure Batteries.
Every 10 hrs, if the roof is up, after the last Ignition Off the Roof System checks the system Hydraulic Pressure and activates the pump automatically if required. This is done without Ignition On.

 

[pjm-84]

I thought this may be the case, because of the current draw, but wasn't sure because of the requirement to have the ignition on. I missed the question mark.

I need to understand what regulates the charge to the leisure batteries when the engine is running. Is it the split charger or alternator?

I need a workshop manual!

 

[sidepod]

Are you sure the fridge isn’t coming back on again after a short while if engine running?

A theory (only guessing here) is that it drops out momentarily similar to the radio when you use the starter motor. Obvs supply is reinstated immediately via split charge system but perhaps the drop in voltage is resetting the fridge electronics and it takes some time to restart?

So many things to test on this one.

 

[Loz]

Split charge is just a relay which effectively joins the leisure batteries to the starter battery .

Can you define what you mean by “trips” ? How do you know?
Does the fridge button light go out?

As @WelshGas says re:roof hydraulics are powered by the LB.

 

[pjm-84]

Thanks. By "trip" the fridge light goes out and the icon flashes. Then it needs to be reset by holding down the bottom right button for "five" seconds.

Fridge has been on max for 12hrs at moment. Had all the lights on for about 45mins last night and ran the night heater. Display dropped down to 12.2v + 90%. This morning (just fridge still on) back up to 12.5v + 90%. Batteries seem to be holding fine.

It only trips when the van is running. Not during the starting process. The only common denominator is that the display is showing 14.6v. If its less it wont trip. However I was only able to observe this yesterday so maybe I need to do some further observations.

 

[WelshGas]

Thanks. By "trip" the fridge light goes out and the icon flashes. Then it needs to be reset by holding down the bottom right button for "five" seconds.

Fridge has been on max for 12hrs at moment. Had all the lights on for about 45mins last night and ran the night heater. Display dropped down to 12.2v *+ 90%. This morning (just fridge still on) back up to 12.5v *+ 90%. Batteries seem to be holding fine.

It only trips when the van is running. Not during the starting process. The only common denominator is that the display is showing 14.6v. If its less it wont trip. However I was only able to observe this yesterday so maybe I need to do some further observations.

Are there any Diagnostic Codes on the Control Panel?

Check Control Panel Diagnostics.

Control panel On

Press and Hold R lower button and then press Control Knob for 5 secs.

New Hidden Menu . Scroll to VW Diagnostics.

If there are any codes shown, take note and then Reset/Clear.

Return to Main Menu.

Switch Off Control Panel using L lower button. Wait 30 secs and Switch On.

Try Fridge

For those of you who don't know, if you ever get any problems with roof stuck or any other error say with the heater, you are able to access the hidden menu in your control panel as used by the VW Engineers.


Access as follows:

1. Hold down the centre of the rotary button together with the menu button (button below with the squares on it)

2. You will get the hidden menu.

3. Rotate the rotary button to get to "VW diagnose" and select this by pressing on the centre of the rotary button.

4. If no errors are present it will display "no errors"

5. If Errors are present then a list of errors will appear

6. Press the centre of the rotary button again to delete all the errors

7. Repeat process above just to check that errors have dissapeared!

8. Re-configure the time and date if neccesary.

Any problems should be resolved assuming these are Electronic and not Mechanical.

Error Codes from Control Panel.

1 = 1 = Pop-up roof


2 = 2 = Plumbing Heating


3 = 3 = Cool box Cooler


4 = 4 = Sewage wastewater


5 = 5 = Fresh water fresh water


6 = 6 = Outside temperature outside temperature


7 = 7 = Battery


Error Code Defect Fault


1010 1010 Short-circuit to (earth) roof


1001 1001 Fuse / short circuit to (plus+) roof


1100 1100 Short-circuit output Roof "on"


1101 1101 Fuse roof "to"


1110 1110 Short-circuit output Roof "to"


1111 1111 Fuse starting Roof "to"


2100 2100 Short-circuit output heating on / off


2101 2101 Fuse output heating on / off


2001 2001 Interrupt input heating 30


3100 3100 Short-circuit output coolbox


3101 3101 Fuse interrupt output output coolbox


3001 3001-J698-cooler input error "Active"


3010 3010 Short-circuit input icebox "actual temperature"


3011 3011 Interrupt or fuse input icebox "actual temperature"


4000 4000 Short-circuit to ground water level sensor


4001 4001 Fuse circuit to plus water level sensor failure


5000 5000 Short-circuit to ground water level sensor


5001 5001 Short circuit to plus water level sensor failure


6000 6000 Short-circuit to ground temperature sensor or for outdoor temperature


6001 6001 Fuse / short circuit to plus two temperature sensors for outside temperature


7001 7001 interrupt input interrupt input D +

 

[sidepod]

As stated, you need to establish the presence (or not) of a 12v supply at the fridge terminals when the engine is running. Once you know this then you know it is/isn’t the fridge at fault.

 

[pjm-84]

Thanks. Handy to have. Mine is showing no errors

 

[pjm-84]

Voltage is present with the engine running. I need to check when the fridge has tripped.

 

[pjm-84]

Okay is cant be voltage cut out.

The range for the Danfoss controller on standard battery protection settings is 10.4v to 17 volts (the higher voltage protection is consistent for all resistors)

Looks like a drive tonight with a multimeter.

 

[MattBW]

Could it be the blue motion? Under braking or deceleration when the amps increase?? Very intriguing.

 

[pjm-84]

Okay. Just checked and LBs at 12.4v and 80%. Fridge is 0 degrees. So that side seems to be working.

Checked my main battery and somewhat dismayed at 12.2 ish reading. Even on tickover its only going up to 12.4v. I would have expected 14v plus

 

[WelshGas]

Okay. Just checked and LBs at 12.4v and 80%. Fridge is 0 degrees. So that side seems to be working.

Checked my main battery and somewhat dismayed at 12.2 ish reading. Even on tickover its only going up to 12.4v. I would have expected 14v plus

Agree. Both Engine and Leisure Batteries voltage rises to 14.4 V to 14.6 V when idling following a Start.

 

[sidepod]

Possible problem there with the alternator but it should still be enough to run the fridge at 12.2v.

 

[MattBW]

Do you have a means to check the OBD for faults?

 

[pjm-84]

Currently on hook up charge but I've never noticed that it charges my main battery as it can be slow to turn over after 5days plus on a campsite even when hooked up. To overcome the issue I disable the electric side door.

As a precaution I have ordered a new vehicle battery. Away for 5days on Wednesday. Will check the voltage when I get back tonight.

 

[pjm-84]

Good idea. I have an OBD reader.

 

[pjm-84]

Double *******. I now see that the battery needs to be coded to the vehicle. I suspect that this will not be possible on the OBD.

 

[MattBW]

Where abouts are you? I have a vagcom device you could borrow, or many members have a VCDS cable.

 

[pjm-84]

Southampton.