Hi, My advice is to change the Final Stage Resistor. It is a really easy job to do yourself and the resistor itself is only about 35 pounds. Might save yourself a lot of money and in the worst case scenario, you will have a spare resistor for when it does it go.

 

Just tried to locate the resistor and I'm really struggling - its late and dark, I will try again in the morning and order the part. I will update this thread when I know more.

 

UK - So drivers side foot well, where you rest your left foot when driving, above where your toes would be. It can be difficult to get at, but you can remove it without removing the dash! )Unbelievable incompetent dealer wanting to remove the dash!!!!!!!)

The fan is controlled by a voltage amplifier which receives required fan speed set point from ATC ECU. This voltage amplifier (strangely known in the community as the "final stage resistor" for reasons unknown) sits between the air inlet and the HVAC evaporator (it needs airflow to cool the output stage electronics) and is located as described above. I would agree that this should be your first line of troubleshooting and the mostly likely candidate for the fault. However, if this does not fix it, then the fan motor is the next stop. Agree with BGMan - is the new amplifier does not solve the issue, at least you have one for when the amplifier goes... as it will go someday.

The whirring you hear are the distribution flaps moving - this is normal, however should not last more than 10 seconds. If they are noisy, the small gearboxes may need lubricating.

Hope this helps.

 

Thanks for your gyrogypsy, I'm getting the part sorted tomorrow and I hop to have an update soon - I really hope it is that and the only problem I have to sort is my back as it contorted into that position to fit the part

 

hi gyrogypsy and BGman, I have now replaced the Final Stage Resistor (hedgehog), as suggested. I even changed the pollen filter because the parts guy at 'Landrover Stealer' did a job on me. Unfortunately, still nothing works. this time however I did start getting a humming sound and an awful smell. DO I need to get the dash out and look at the heater motor now? I really appreciate any advice on this?

 

OK - Sounds like the fan motor is either seized or the motor is a dead short.

I am thinking the burning smell maybe the electronics of the amplifier (FSR), as the motor may be shorted. So now you need to test the fan motor. Easiest way is to do this (without removing the fan), is to pick up the Black/Green and Red/Green wires on the amplifier connector. These wires go straight into the fan motor for the front blower. Apply 12v directly (from the battery - polarity does not matter but do it with both polarities) on to the wires and listen for the fan motor to run (it will run at full speed!). If you hear it running, then we need to look at the HEVAC control module (ATC), if you do not hear it running, then the motor is dead or the fan is seized.

Revert back and let us know.

 

Thanks for your reply and help - I get your drift and I will do that tonight. Can I use household electric wires? and run them from the battery to the pins?

 

Yes, household wiring is fine - you are only going to be testing quickly just so you can hear the motor/fan. Pick up pin 1 and pin 5 on the connector and briefly touch the battery wires to the pins. You should hear it start straight away.

Just to add that this is not the professional way to test a motor, but with limited tools and equipment it does the job. Had to add this as I am not a cowboy.. I am just providing an easy way to test.

 

will do, and totally value that advice. I will get cracking! If this doesn't work - am I taking that dash off?

 

If the fan is U/S, I am not sure if you can replace it without removing the facia. I will take a look when I get home tonight and let you know.

 

Bad luck I am afraid - it seems that he fascia has to be removed. The good news is that you can do it yourself and it does not look that difficult (well, not as difficult as I first imagined to would be).

Get RAVE manual for reference, and the procedure is here (best with two persons, especially when removing HEVAC assembly):

1. Remove Glove Box
2. Remove center facia (biggest part of the job)
3. Remove air blend motor to gain access
4. Remove 4xTorx head screws
5. Remove 2xnuts to remove HEVAC assembly
6. Release 2xclips on top of fan unit
7. Disconnect cable to motor
8. Remove 3xTorx head screws from fan assembly securing the heater

Have a beer, relax, and fit new fan motor.

Re-assemble.

Unfortunately, I have not done much with HEVAC system apart from fan controller (FSR). RAVE makes it look easy, but RAVE also made changing the VANOS look easy, when it was not (in fact it was a %$#&&* *&^!)

Confirm it is fan motor first, then take a deep breath.

 

hey gyrogypsy - after a full on few hours today I have managed to take all the dash off and this is the situation as you can see from the pics below. If you are going to do this, I strongly recommend you give your self a load of time - what a mission! I'm now about to test the motor again as per your recommendation earlier in this thread, just to be sure that this is the culprit - god hope it is!

 

Right the motor works fine and rotates well. I have tested it from a mates motor battery and it ran. Could it be this housing (I assume the blend - might be wrong) and then these 2 motors not turning. As when I pulled it out they where all firmly shut. Appreciate your help - I feel so close to getting it

 

So the fan motor worked when you applied 12v directly to it? Did it work when you applied 12v from the FSR connector?

If the motor is free and turning when you applied 12v directly to it, Then the FSR output voltage needs to be measured. I have to say that this is very strange that the fan is OK, a new FSR, and all the cabling is fine (can you confirm all cabling is good?)

If this is the case, then the only other culprit is the HVAC ECU controller. The flaps you are referring to are the mixer flaps which open and close on command from the HVAC ECU. Did you hear these opening and closing when you open the car doors? Usually when you open the car in the morning, you can hear the flaps opening.

Do you have a multimeter that can measure DC voltage? If so, on the output stage of the FSR, connect the meter to pins 1 and 5 when the fan is connected, and select different fan speeds. The voltage should increase as a higher fan speed is selected. If you want to chat, PM me and I will send you my number.

 

hi mate, like you I was not convinced! This morning I connected the battery again and the heater control unit. I turned the fan on and at varying speeds, whilst the fan motor was exposed. The noise that I have been referring to in this thread was there and clear to see - it was coming from the fan motor. I have taken that out now and am searching for one online. Hopefully that should be it and your earlier diagnostic was correct, just my incompetence. I'll PM you as you have been a bloomin brilliant!

 

Ahhhh... **** motor. Glad you found the problem...

 

Just wanted to say that I managed to get everything working. In short the vent flaps located just behind the main centre air vents stopped opening sue to the vent motor not working. These flaps remaining closed for months then led to the heater motor just blowing away without actually letting the air out, unless it was towards the window or footwell. I ended up taken all the dash off and then over the series of 3 weeks fitted a new heather blower, final stage resistor, pollen filter, vent motor at a cost of £500. The relief having put the car back together and having the heating working is immense - thank you all soooo much and Gyrogypsy you were brilliant!