Dead resistor pack. Will be in the heater box somewhere with a few (4ish) wires going into. Cant remember off the top of my head exactly where it is on those
Yea find the resistor pack, it is probably the fuse that is blown on it. It is a thermal fuse and you can just buy a similar rated one and either solder or just twist it on.
I changed mine and bought the resistors from RS components. $1 ish or something.