Solar Monitor Box PCB fix

PCB Solar Panel Kit Monitor Box

Hi All,

I have a solar kit for camping that has a plug in monitor box. The wires to the PCB inside were soldered poorly and have come loose I am unable to work out what wire goes where. There is 4 wires Red, Black, White and Green and 4 soldered areas where the wires were previously soldered. PLEASE HELP I have been staring at this thing for months trying to work out what goes where

Kind thanks in advance
Ian

We have no idea what is at the other end of the cable!

If we assume (that is the best we can do) that the black wire is negative and red wire is positive, because that is a convention, from left to right they would be red then black. The other two appear to be RS232 data transmit and receive connections, if you have a DVM, solder the black and red wires to the pads, place the black probe on the black wire and measure the voltage on the green and white wires, WITH IT PLUGGED IN. One will probably have almost nothing and the other probably 6V or more, note the one with the voltage. Now measure the 3rd and last pad on the PCB and you should see the same. Connect the wire with voltage to the pad without it and vice versa. No harm will come if the green and white wires are swapped over but the data link will only work with them one way around.

Brian.