It sounds like he has one of the newer ones grayson,to solve hes problem all he has to do is have the Tekkeon power cable into the battery,select voltage, Then plug into vms5u,I ran into this problem when i started using the newer tekkeon its a mp3450,Now i use my older tekkeon that are the 3300 model and they work just fine,the vms5u is great it uses hardly no power at all.This is a simple fix no need to cut wires just a extra step, Hope it helps