How to change block heater wire on 2002 T6??

Tried to test the block heater plug with an ohmmeter and got an open circuit. I traced the plug wire down under the car to some kind of integrated block in the wire (relay?), the wire then continues up to the block. I can barely see where it connects to the engine from under the car, it looks to be a horrible place to try and get at to disconnect the plug wire and maybe run a new one. I'm looking for any suggestions on how to proceed, will I need to run a new plug wire from the heater element on the block all the way back out to the right front? I don't even know how I would be able to gain access to the block heater element to disconnect the wire..
I have Mitchell and Alldata, but they don't have any information that is helpful for this problem.