EDIT I got the controller panel and the solar panel mixed up!
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Clean up the mess till you can get some readings just from the wires at the back of the panel (never mind the controller, disconnect that for now)
When cleaned up, aim the panel at the sun at high noon (1pm for now during fast time), and read the amps and volts. Should get rated Isc or more, and about 2 volts less than Voc for 12v panel or more for 24v panel (loss due to heat)
Now the panel is working right, connect up and see what the controller says. Probably ok.