Climate control acting funny after running a bit low on coolant.

[Gambit]

Hello,

I'm having an issue with my heater...

The other day while sat in traffic I watched my water temperature gauge drop off, it was at it's normal half way and it just dropped off at about the same pace the fuel gauge climbs after filling up.

The traffic started to move as the needle was falling and I started to accelerate, instantly the gauge went back up to normal. I got home and topped up my water levels that were a bit low and topped up the expansion tank that was pretty empty..

Since this the gauge has worked normal but the in car temp is not working correctly.

The other day I drove around with the temp set to 24c and the blower was at speed one and blowing cool air, I turned the temp up to about 26c and the blower speed switched off???? If I crank it up to max temp the blower goes to max speed and good warm air comes through.

What's going on?