If the fuses are ok then its obviously got a short/bad earth, clean all connections up and earth points. maybe try another heater panel? the resistor was dodgy on a mondeo one i had so i bought another, same problem, so thought it wasnt the heater panel, i then spent £50 on new dash loom and all sorts, turns out the second heater panel was just as fucked as the first, 3rd one worked fine !