We just fixed our with a bypass, took photos but this forum has no easy way to just attach them.
Basically we picked up 2 20$ PTC heater elements off eBay 200 watts each and pulled power off the driver side panel fuse box which has an open high power lug we tapped with a 30@ fuse and ran 10 gauge zipcord under the dash up through the defroster vents to the PTC heaters placed center over each defroster vent.
The more air we blow the more power they draw.
They are very fast to defrost, and keep the cable air a touch about e freezing in our Finnish winter's.
I would be happy to email the pics to anyone willing g to take the time to post them online and link them to this discussion...