I have just received my new FB4 and hooked it up, it seems to be OK except for the low volts on the output when relay is on. I have 12.06 volt at the battery supply and 7.8 volts across relay when it is turned on then. The relay keeps turning on and off. I have the jumpers on the 12 volt side on the board.
Can someone help? I can not find the solution in the forms, except maybe a bad FB!?