AC won't go full blast. S13 Ka

[Nick_04K]

My AC controls all work on speeds 1-3, but speed 4 (full blast) won't work at all. The air conditioning just stops. Any ideas?

[Vernal]

The fan blows hot air or the fan doesnt spin on setting 4?

[NIZzS13]

In fan speeds 1-3 the power goes through a blower resistor and high power goes strait to the motor so more than likely you have a broken wire or bad connection on that line.

[badboy6686]

The last car I had that had that problem it was fixed by swapping the whole control unit with another one.