Crap heaters, low engine temp and new 'stat

When I bought my petrol series 3 the seller told me that the previous owner to him used to use a grille blind to stop air getting to the rad and over cooling the engine. I thought this to be a bit strange when our winters are never really as cold as countries where these radiator blinds are common.

The temperature never goes above the C at the bottom of the gauge and even when stuck fast in thick mud and left to idle for 2+ hours it never got as high as a 1/4 up the gauge. To go with this the heaters are really poor. Not only are they luke warm, they only have one speed. I thought Series 3s had 2 speed heaters? The switch is a 3 ways switch and there are 2 wires going to it but only one is connected. The motor is a single speed blower with just one power wire going in to it. My Dolomites had 2 speed blower motors and they had resistors on them which makes me think maybe its been changed?

I've changed the thermostat as I thought that would be the culprit but no change... barely warm heaters and hardly moving on the temp gauge. It does seem to be flowing around the block/radiator just like it should. I do think I've got 2 problems that aren't connected. I tried flushing out the heater matrix but it was pretty clean to begin with and theres no difference. Still cold...


Any ideas?

you need a rad blind m8,
most of the older cars i've had have needed them, they must be wayyy overcooled but ya see plenty of series with blinds fitted over the colder months