vp commodore, heater is on all the time cannot adjust

Check the blower motor relay could be sticking

heater tap on R/H/S below master cyl, may be faulty and if vacuum line off tap goes to hot, also listen for vacuum leak under dash near heater control, the switch is a vacuum switch and this can also be a problem.

thank guys but that does not seem to be what its problem is?

A bit more precise info on what the problem is, as much detail as you want.

OK, the heater seems to be on all the time, the heat/cold switch is on cold. have changed the settings on the dial, heat still comes out.

the air feels fresh so i think the air-con is working.

check for vacuum at the heater tap, if the control is on cold and both heater hoses are hot, either the tap has failed or there is a problem with the vacuum side of the heater system, the main switch for heater and vent controls is vacuum operated.