Zanussi ZD694W PNC 911841090 sporadic failures

Zanussi Integrated ZD 694W
PNC 911841090
Product Type: 911N82-2F

Hello,
Have a Zanussi ZD 694W dishwasher at my parents house that is many years old and has never really worked that well. It will work if it has been left to stand for a long time but then after a few cycles it will fail, with the circuit breaker fuse tripping. I had originally thought it might be something to do with the rubber seal at the bottom of the front panel of the unit letting steam up that would then cause the controller selector at the front to short connections when water vapour had condensed.

Running the unit with the controller panel taped to the front of the unit with suitable insulation between contact points still lead to the unit tripping so water vapour does not seem to be the issue here.

I have taken the side panels off to see if I could see any way of getting to the larger components and put a multimeter across any of them and see if anything was shorting but could not find any easy access to the main components.

On the left side the water softener and resin is blocking access to the lower side of that unit and on the right hand side I can only see the power terminal strip block and a grounding wire and not much else.

The dishwasher can run through the whole cycle several times without an issue and then when it fails all it takes is the power being back on for it to trip again. I can detect a resistance that gets generally larger between live and earth when in this failed mode. Eventually it goes back to full open circuit.

All the components seem to be working, if it gets through a full cycle the dishes are clean and the expected amount of hot water vapour comes out when opening the door and the water is drained correctly. The spinning arms, the heater, the pumps all seem to be working and it’s difficult to identify the individual component that is failing without access to the primary components. I have no idea how to get the water softener plastic unit off the side, it seems to have the resin and some water in there. I’ve found some service unit sheets but at this point am a bit lost in how to proceed to get to the base components and find out which in particular is failing. Kind regards and thanks for taking the time to read this.