The lights have stopped working on the heater controls on my V40. 2001 with auto A/C. Can i repair it or do I need to buy the complete unit.

There's a website reliable-store.com that has all this information about all these automobiles and their repair manuals everything totally free there are many actually but I personally like few .. let me know if u need help
thanks

You need to be a bit more specific. Did the amber temperature/fan speed display stop working or did all functions stop as well? The control units are prone to fail on these cars as is just the display. There is also a control modules that can go bad as well. Repair of the module is not cost-effective option. I would first suggest having the BMW codes scanned and then replace the offending control or module with a used one. Part will be less than $100 plus you and cost for running codes.

Good luck,
-Scott
EuroPartsPlus.com

When I had my Buick we had problems similar to this and we just went to the auto wreckers and pulled one out of another car and replaced it and then it seemed to be fine. It's relatively easy to replace and a cheap fix, the unit cost us around $10 at the auto wreckers.

you don't have to replace the heater but get a new heater control switch and install it then all should be right as rain. Good Luck

This is nothing more than the tank sending unit that has failed. I would look into a junk yard and see about buying a complete unit(pump/sending unit assembly). It will be substantially less than new. Let me know if you need instructions on repair.

here is a suggestion--go to any auto parts store and buy a haynes manual for your make and model car. they are based on a complete teardown of vehicle. for only about 20.00, the manual will tell how to remove heater core.

Download owner guide first printing from below link

http://www.motorcraftservice.com/vdirs/SPubs/default.asp?TYPE=OWNERGUIDE&pageid=oghome&gutsid=spubs_serv_all_new&MARKET_LANG=US-EN&YEAR=2003&VEHICLE=Expedition

after downloading go to page number 231 where you get the fuse box diagram
fuse for the radio is #7 in the fuse box diagram

it works completely

U must remove the climate control unit from the dash and remove the top cover of the unit, u will find a tiny twist in light bulb socket with a tiny little light bulb, this provides the backlight for the AC/heater display, u can buy the bulb at any auto parts store, couple of bucks.

From what you are describing it sounds as if the headlight switch has gone bad.  That switch controls not only the headlights but the tail lights and all dash lights.  Everything that IS working is connected to other switches not related to the headlight switch.  You can either buy a new one or get a used one from a junk yard or ebay.  Pay particular attention when getting a replacement as there are 3 different models which vary depending on options such as Auto mode and Foglights.   Replacement is easy.  Using a flat screwdriver carefully pry off the trim cover around the switch. The switch is held in with some screws.  Be careful disconnecting the wires so as not to break the locking tabs. The trim just pushes firmly back into place.

The heater works from hot water from the engine. The flow of hot water into the heater is controlled by the climate control computer. If this is not functioning properly it can be heating even if you have switched it off. Fixing the climate control system may be complex. The flow of water is controlled by valves which may be jammed open causing it to heat all the time. These are under the dash so to fix them you will have to dismantle most of the facia. This can be done but you may battle to find all the concealed screws and clips. If you try it take a careful note of where everything fits so you can put it back later.

To disconnect the heater completely you have to locate the rubber hoses that carry the hot water from the engine into passenger compartment. There will be 2 hoses, one carrying the water in and one carrying it back into the engine after it has circulated through the heater. You can stop the flow in 2 ways, as follows:
1 Disconnect both the in and the out hoses from their respective manifolds, buy a piece of rubber hosing the same size from your friendly auto parts store with 2 hose clamps and fit it between the in and out manifolds. This will take your heater out of circuit completely.
2 Put a clamp on the "In" hose (this will be the hose connected to the engine at the front near the water pump). You can do this with a "C" clamp that you can buy at any hardware store. This will stop the water flowing throough the radiator.

Good luck and stay cool.