you need to run 4 gaug or bigger coming from the battery to the isolator figure out the max amps it need to turn on the compressor and put a fun inline on the 4 gaug wire then run 6 or 8 guag to the compressor to this what happens is the wire you are using is to small and the amps from the compressor is to much for the wire if you dont use the same gaug for ground as for power it will make the compressor work harder and get way to hot . long wire run with to small gauge wire produces resitance and most get hot until a fire how to fix it is the longer the wire run the bigger the wire gauge you need 0/1 or 4 gauge for long wire runs from battery then a distribution block to split it to smaller gauge wire like 8 gauge to amps or compressors any question email me
fredstinting@yahoo.com