To Replace Climate Control Resistor Pack

[andybond]

By benkay Forum Topic


I finally got around to doing this.


Symptoms


Climate control computer is ON and temperature and blower control appears to work, but no air is blown from the vents.


The Fix


The blowers use a resistor pack to regulate the speed of the air blown through the vents. A MOSFET transistor is used in order to do this, and it is this component which fails.


A new resistor pack is around £120.00 from Renault, but this fix will cost you about £5 and a bit of time.


The Tools For The Job

• Large flat head screwdriver
• Thin bladed knife (maybe)
• M6 hex driver (straight and ratchet with UJ)
• Soldering iron
• Solder sucker or gauze
• Solder
• New MOSFET HUF75337P3 (Maplin part number UE47B, LINK)

Guide

1. Pop the bonnet. You will see under the windscreen some scuttle panels, the resistor pack is under the O/S (driver's side if RHD) scuttle panel. First thing to do is pull off the rubber seal as shown above. You only need to pull off until about the midpoint of the car.
   
2. The scuttle panel is held on at two points by different methods. First, tackle the circled screw rivet.
   
3. Use a fat flat head screwdriver, coin, or another key to turn the central part of the rivet anti-clockwise about a quarter turn. The central part of the rivet should raise up slightly; now pull the central part up. This releases pressure on the outer part, allowing the entire rivet to be pulled out. If the whole rivet spins, use a thin knife to raise up the inner part.
   
4. The end of the panel nearest to the centre-line of the car is held on with two clips. Push these clips backwards and then lift the panel upwards and forwards.
   

Ta-daaa!

1. Now that the panel is loose, pull it upwards over the metal lip of the scuttle and towards you. You may need to pull the panel away from the edge of the boot opening to allow this little rubber locating piece to pull out. Don't forget to relocate this piece when reassembling!
   
2. Now you can see the resistor pack clearly, circled below.
   
3. First, remove the wired plug from the pack. Push the two marked tabs inwards and then pull the plug off.
   

Like so...

1. The pack is held in place by two M6 hex-head bolts/screws. The left-most one can be removed with a normal driver, but the right one requires a small ratchet with a U/J linkage.
   
2. Once both fixings are removed, pull the pack out (tilt slightly forward to clear the bottom of the windscreen).
   
3. The pack is now removed. There are six tabs securing the case. Use a thin knife to pry them open.
   
4. Remove the back part of the case first. It may need some persuasion, as the insides are full of silicone.
   
5. Now remove the front cover carefully to avoid snapping or bending any pins.
   
6. You'll be left with this...
   
7. This is the faulty component...
   
8. Lift the tabs of the metal retainer up and push it forward slightly to relieve pressure on the MOSFET. Bend the MOSFET forward slightly and insert a thin piece of wood or rubber between it and the heatsink to prevent excessive heat absorption during soldering.
   
9. Turn the unit upside down and remove as much silicone as possible. Use a hot iron and a solder sucker to remove the existing solder. Pull out the old MOSFET and solder in the new one.

Note: The new MOSFET is a different size, so you will need to splay out the legs slightly to fit.

1. Reattach the metal cage and reassemble the pack. You may choose to refill it with silicone, but I didn’t bother.

Here’s the difference between the old and new MOSFETs:



Reassemble everything in reverse order.


You should now have fully functioning climate control again!


Hope this helps, and good luck if you give it a shot!