Ctek D250s error on solar

If you have the temp sender hooked up to the service battery, try disconnecting it briefly to see if the fault disappears. Monitor the battery temp with your hand while you do this just to be safe

Today I removed the temp sensor of the battery and reconnected the rooftop solar and within a minute the display went from normal input to error.
I once again connected car and auxillary and it works fine. Driving me crazy.

CSeaJay
If that is the problem, then if the panel is the one which has been used successfully in the past, it would point to it being a problem with cable or connections or high resistance not passing sufficient current / voltage under load to the Ctek.

I don't have the specs. for the panel. Just checked open circuit value @ 21.2v

Therefore, at the end of the wires which go to the dc unit, you should have approximately the same open circuit voltage, and if you place a multimeter on AMPS setting, providing the panel isn't more than 10 amps Pmax current, directly across the terminals of the solar wire, the full ampere delivery of the solar panel to the plug or wires at the DC unit should be a reasonable amount. Never is it what the panel says though.
That way, you know panel voltage is present at the dc unit and amps available for use too. If OK, then the DC unit becomes in question. First things first.