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  Heater Matrix
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The Granada Haynes Manual and the official Ford Manual (thanks to the member who copied the relevant pages for me!) both describe how to remove the complete heater box, but not the more likely task of heater matrix replacement

It is not necessary to remove the complete heater box to replace the heater matrix. The heater box needs to be pulled into the passenger compartment and turned a bit, only sufficient to remove the matrix from the driver’s side. Therefore it is not necessary to remove the steering wheel, the passenger air bag or the fascia crash pad as described in the manuals. (The Scorpio fascia crash pad is in one large piece (unlike the Mk 3 Granada) making it difficult to remove from the car).

The heater matrix on the 2.3 Ghia car is identical to the Sierra and Granada unit. The other models may be different. Cost £31 from Partco. The Ford garage quoted an amazing £97. Stories from “Honest John’s Website” of £500 to replace the heater matrix start to look possible.

The heater matrix came with a label saying that inhibitor and demineralised water must be used in this system. But if it’s the same unit as the Sierra and Granada why is heater matrix failure on these models fairly rare yet mine failed after four and a half years?

The most difficult bit below was removal and refitting the heater hoses and retaining plate at the bulkhead in the engine compartment. Fortunately this comes early on in the procedure so if you have to admit defeat you won’t have got far.

Removal procedure
1 Disconnect battery  
2 Drain coolant. Can be drained via the lower heater hose at the pump end to avoid removing the undertray  
3 Disconnect heater hoses at the bulkhead after removing A/C drain pipe. Access is very tight but water pump pliers on the clips worked OK. (V6 Owners may need to remove some engine inlet ducting to get better access)

Heater hoses on bulkhead before removal

Matrix connectors on bulkhead after hose removal

Matrix hose connector retaining plate and gasket – note how my stubby screwdriver was too big and I needed to make up a smaller screwdriver

4 Remove the two heater water hose retaining plate screws. Not easy but a small stubby screwdriver will just fit. Remove plate and thick rubber gasket. Gasket should be OK to reuse if not damaged  
5 Release steering wheel lever and pull steering wheel out and down to maximise clearances  
6 Remove the radio, pull off heater control knobs  
7 Lever out the trip computer switch with a small screwdriver and disconnect at the multiplug. Remove the lower fascia (five screws) as described under “Instrument Bulbs” on the Website. Disconnect the bonnet release cable from the lever, (pull in the slack and it can be released just like a bicycle brake lever). Disconnect the OBD2 plug from the panel  
8 Remove instrument fascia as described under “Instrument Bulbs” on the Website (six screws and pull fascia gently). Ease forward and disconnect multiplugs for lights, clock, heated windows and heater switch (if fitted). If necessary remove the drivers side face level air vent connection from the fascia (three screws) and remove fascia from the car.
Note Take care when removing multiplugs. Many of these cannot just be squeezed to remove, they have a small locking lever which needs pressing with a screwdriver. Easy when you can see what you are doing - not so easy when doing by feel alone

With the fascia removed - no chance of getting at it yet

9 Open cassette storage box and remove the handbrake switch panel (two screws) and slide over the handbrake. Remove multiplugs  
10 Manual - Unscrew the gear knob. Prise up the gear lever trim panel and slide the gaiter over the gear lever. Auto - remove trim panels but leave selector and switch panel in place.  
11 Remove the remaining centre console screws (two at the front and three at the bottom of the cassette box) and lift off, removing multiplugs for cigarette lighter, etc

With centre console removed – still to remove brackets.

12 Remove main instruments (four screws), ease forward and remove three multiplugs. Remove instruments following the instructions to keep it vertical  
13 Gently lever up the crash pad upper bezel (next to the windscreen). It clips in place  
14 Removing the ash tray (four screws) should let a bit more light in but annoyingly there is no obvious way of disconnecting it electrically  
15 Remove heater control panel base (four screws) and push back into dashboard. (This allows the fascia crash pad to be pulled back without being held back by the heater control cables. Alternatively the control cables can be released at the heater but then they will have to be readjusted for length during reassembly). For Cars with CC the HBC module can be easily removed and there are no control cables to worry about.  
16 Reach into dash and remove centre vent duct (two nuts)

Removing Centre air vent duct

17 Remove glove box by prising off the two spring clips and pulling the box out  
18 Remove 'squarish' plate around the gear lever (four screws) and the bracket just in front of the gear lever (two screws) which is preventing the fascia crash panel from swinging out  
19 Release fascia crash pad at the top (three screws below the windscreen) the side (one screw by the passenger door, two nuts behind the glove box, one screw in front of the steering wheel) and the bottom (two screws in front of the gear lever)  
20 Pull fascia crash pad out and up a few inches. It won’t go very far due to the steering wheel. Keep an eye on the passenger air bag wiring. Wedge it up near the gear lever (or engage first and rest it on the gear lever).
If no passenger air bag, the fascia crash pad can be removed by maneuvering around steering wheel after removing three connectors for the ashtray near the heated window switches.

With Fascia crash pad resting on gear selector – hardly any space to work.

With Fascia crash pad completely removed

21 Detach each rear footwell nozzle from the heater by pushing in the pin in the centre of the retaining clip. Losing the pin down the air duct is almost certain. Prise the two heater ducts apart and wedge them with something suitable to allow the heater to be moved out into the passenger compartment  
22 Remove the two nuts securing the heater box to the bulkhead. Note that the bulkhead here is horizontal, (below the air conditioning cooler)  
23 Release the four heater ducts from the heater box. [Removing the vent trunking from the passenger side vent (one screw at the fascia end) and the demister vent (one screw and one nut) may help]. Some cabling nylon ties and bits of sponge may have to be released to access demister vent screws. Removing the equivalent bits from the drivers side is near impossible as it snakes over the steering column, so try do it without

After removal of heater bolts and moving it a couple of cms- may be enough clearance on LHD to change matrix at this point

24 Pull heater box into the passenger compartment. Unlike the rest of the fascia the heater box is made of a very brittle plastic which breaks easily, grab the whole box and pull gently. It will probably catch on the bulkhead insulation which is heavy rubber backed and doesn’t bend easily. Consider cutting it if necessary (and gluing it back afterwards)  
25 When the heater box has moved a few inches, remove the two screws holding the heater matrix to the heater box. Rotate the heater box and ease into the passenger compartment until the heater matrix can be removed past the steering column and pedals

Heater pulled about 30cm into car, matrix almost fully out.

New Matrix ready to go in.

Replacement procedure

Reverse of the removal procedure

Reconnecting the heater ducts on the drivers side is very difficult, particularly the face level vent connection as it fits at an angle. Consider cheating and cutting 3-4 axial slots for the last two inches to make it easier to stretch over the heater. Then secure with a cable tie.

Replace the hose plate and gasket in the engine bay before putting the dash back in case you need to lever the heater box to get the screw holes to align.

Leave all cut cable ties in place as a reminder to replace when putting back together.

When refitting the heater water hose retaining plate it will probably be difficult to locate the two screws in the bulkhead. Try slightly longer screws (but check the screws you use are not so long they risk penetrating the heater matrix) and temporarily securing them with 'Blue Tac' to hold them in place while you get the plate into position.

Here are some diagrams to assist you

2.0 and 2.3

2.9 24V

2.9 12V

Interior Lower Unit

Interior Lower Unit

Interior Upper Unit

Interior Upper Unit Ducting






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