Basically it goes on and then when l start the engine it wont work at all. Sometimes while driving it will randomly just come on but otherwise not and l need it to work. Can anyone help?
Also, rear door isnt locking via central locking or pressing the button. How hard is thiis to fix? One more thing,when the fuel line goes into the bosch fuel pump, does it then go straight into the engine? Just need to know for a modification im making.
Thanks yall.
Thanks so much guys The info is superb and l will pass the info onto my mechanic if l cant do the jobs.
l will award best answer to the guy with less points because l wanna give to him.
THANKS!!!!

Fan could be an ignition switch fault, the accessory circuit position may have become faulty on the electrical part of the switch - get a Haynes manual & check for voltage at the accessory position with the ignition on.
Rear door is probably a faulty solenoid - cheap & easy to fix. Good source for everyday spares here;
http://gsfcarparts.com
When u mention Bosch fuel pump, l assume it is a diesel. If so, the pump is mounted on the engine & then feeds all four cylinders' injectors directly via high pressure steel lines.

The blower works through a relay connected to the ignition switch.
When u start the engine, the power to the blower is cut, helping to get full power to the starter.
When the engine starts, & u release the key, the power should return to the blower. ur relay is faulty.

Door fault is the solenoid or wiring.

The last question is hard to answer without further info on the type of engine, but presuming it is a diesel model.
The fuel may go from the pump to a fuel distributor, which then injects fuel into each cylinder in turn.
Direct injection does away with the fuel distributor, & uses electric solenoids on the injectors to control the fuel from a common rail.