not too sure this will work out ok, but..
as my daughter switched on my non working jammed, heater blower, last time my j plate disco was on the road, she phoned to say the disco was alight on the seafront!....
found her parked on a mini round about with doors and bonnet open..
cut a long story short / she had burnt something out big time in heater i guess.
lastweek i fitted 2 x 50mm 12volt pc cooling blowers into demister pipes, firstly cutting 4 x inch pieces from empty silicon gun-tube, then epoxy glued onto each side of 12 volt blower fans, slit demister pipes, cable tied in my blower bodges, took power from bigger power wire out of heater switch / cut and taped wire to non working fan. blowers dont blow a storm, but do move air when stationary, more when on the move. have room for 2 more perhaps....like one of bustersbus photoclips, can use a 12 v ceramic heater blower ontop dash if needed in severe weather....just did`nt fancy taking out dash for heater fan replacement...