Firstly, you frequently find heating controls (hot and cold) are directed through the same fuse. So, I would consider checking the fuse first. Not sure where they are on one of those, so owners manual would be a good bet.
Second, it's likely that the system requires there to be full coolant levels in the air con system. So you may have a leak (and when it gets too low, the safety system will cut in and disable the heating/cooling to safeguard the compressor). That's the second choice. Other than that, sorry no idea. They would be my two first options to check.
It is for reducing petrol when climate control is switched on
One of your Cat Convertors has a problem
i have a vectra as well, the only way i figured out was to remove the traction control/abs fuse, but in doing that it also is the fuse for the speedometer, so a bit of a problem there
Defective heater blower motor resistor pack.
Check the fuel injection air-intake. I had a similar problem on my Alfa when there was a leak in the pipe between the air-filter and the manifold. idle control switch on throttle body try taking off the idle control valve and giving it a good clean out with some choke and carb cleaner it comes in a spray can i had this problem with my vectra apparently it is a common fault with them once i cleaned the control valve all was ok
Traction Control. Standard on 2.0 and V6.
The idle air control valve on a Vauxhall Vectra B is located on the intake manifold. The valve is placed in front of the air tubing, right behind the engine cylinder head.
The cruise control fuse can be found in the fuse box. The cruise control fuse will be at the bottom of the first column.
I had the same problem on my Vectra B. Mine had refused to turn and I used Graphite powder and played with the key until it turned. it come in a little "puff pack"
idle control valve faulty or needs cleaning
hi just had the same problem, clean the idle control valve with carb cleaner job done :-]
vectra b is the earlier engine