Solar charge controller question

[GregW]

I'm a bit puzzled, when the tarp is covering the top of our camper to keep it dry, the display on the controller shows the system is working. However, when the tarp is off and the camper is ready to set off on an adventure, nothing shows on the display and however much button pressing and cursing at it I do, the display remains blank. I have a new controller ready to fit but if it is really not broken I don't want to fix it! Any comments gladly received.

[spirou]

Details and photos could help. What controller, what exactly is it showing when you think it's working and when it's not?

 

Edit: also, has it ever worked normally before and how is everything wired?

Edited November 17 by spirou

[GregW]

Will try to remember to take a photo at the weekend, I think it is actually working ok, when the tarp is off, the panel pumps out about 40v d and I think the cutout is 39. 7? the battery has good voltage and it is charging at just over 13.? volts. As a novice I think I just over thought it!