range rover classic 1993

can you help me. my heater fan only works on no 3 for about 1 min.then stops.but makes a loud noise.please its cold help

Sounds like a problem I used to have with an old Mondeo (a well documented one), not certain RR is same but it's likely. Check the ballast resistor pack it's probably burnt out on the resistors for slower speeds and the high speed is heating up and failing.

Where is th eballast resistor located? is it in the wiring loom to the Fan or in the heater assembly itself?
I may have one at a reasonable cost as I have a RR in the garden in my way

what is a balast resistor.? where does it live.?

Near Bath..... he's been resisting his ballast for years

If thats your only problem on a classic you are lucky lol

i wish

Hi Steve,

From memory the ballast resistor is located behind the air intake vent on the bulkhead.

The ballast resistor works by controling the total load imputted into the electricery to control the motor a various speeds, when you drive forward air gets forced into the intake and can speed the fan up which in turn speeds up the motor which is being supplied with electricty to turn at a slower speed than it currently is....the way a motor works is to pass the current through a coil to generate magnetisum which pushes against the field coil magent on the motor case.....this current then goes onto the next coil to generate another magnet etc and this pushes (or pulls depending on how the motor is wound) round. If the motor starts to go faster than the magnetisum pushing (or pulling) it then a process called back EMF (Electro-Motive Force) is generated and this gets fed back into the system which the electrical system wouldn't like so a ballast reisiter is fitted to control the motor speed but is also fitted with a diode pack to prevent any back EMF from shorting the system out.....

Hope that is as clear as mud.....it is behind the air intake grill on the bulkhead by the bonnet....

Rgds,
Saint.

thanks for the info.i will check it out on saturday.steve