To bridge the wires just use a old piece of wire, strip 1/4" insulation from each end and jam in the plug.
The heater is like dead centre behind the controls, if you get down in the drivers footwell you should see the cable that moves the flap, and the flap on the side of the large plastic heater box, make sure this is getting full movement in the hot position, if not loosen the philips screw and move cable along slightly so the flap cam move full travel, has it had a recent matrix ?, maybe it wasn't put back very well, some dodgy people when selling cars bypass the matrix(if leaking) so this would produce no heat.
tabetha