Heater Pad Backrest, Replacing
Heater pad backrest, replacing
Special tools:
115 8962 CRIMP PLIERS 115 8962 Crimp Pliers
Note! The illustrations in this service information are used for different model years and / or models. Some variation may occur. However, the essential information in the illustrations is always correct.
Preparatory work
Removing the front seat
Remove the front seat. See Front seat, replacing Front Seat, Replacing.
Partially remove the backrest upholstery. See Components backrest, replacing Components Backrest, Replacing.
Caution! The old heater pad must be removed first. A new heater pad must not be bonded over the old pad.
Note! Read through the entire section before beginning work.
Types of heater pad
A sequence of illustrations displaying a number of different heater pads for both the seat cushion and the backrest now follows.
Caution! It is imperative that the correct type of heater pad is used to match the shape of the foam filling.
The heater pads displayed in the stages below apply to both the front and rear seats.
General information about different types of heater pads
Heater pad for backrests and cushions, front seats
The heater pad for the backrests and cushions, front and rear seats
General information about foam filling
Foam filling with front-rear channels and one lateral channel.
Foam filling with front-rear channels, one lateral channel and a design channel.
Foam filling with front-rear channels, two lateral channels and a design channel.
Foam filling with linked front-rear channels, two lateral channels and a design channel
(The channels are used to secure upholstery to the foam filling.)
Replacing heating pads
Removing upholstery
Remove the adjustment knobs, head restraint and upholstery. See Components backrest, replacing Components Backrest, Replacing (-2002) or Components backrest, replacing Components Backrest, Replacing (2003-).
Removing old heater pads
Slide the backrest backwards.
Disconnect the connector from the cable harness.
Carefully heat the old heater pad to remove it.
Caution! Ensure that the foam filling is not damaged when removing the heater pad. Ensure that the pad is detached from the foam filling. This is to avoid functionality problems when installing the new heater pad.
Note! Damaged foam filling must be replaced. This to guarantee function. This also applies to damage due to cracks in the backrest and seat frame.
Installing heater pads
Positioning the heater pad
Caution! Ensure that the heater pad is correctly positioned so that the half moon clips can be secured clear of the heater elements and the surface of the heater pad.
Position the heater pad in the correct position. Do not remove the backing from the adhesive surfaces.
Secure one half of the heater pad.
Bend up the other half of the heater pad.
Pull the backing (or part of the backing) off the adhesive surface closest to the center of the section of the heater pad that is bent up.
Carefully bring the adhesive surface down onto the foam filling. Work with small sections at a time. Start from the center and work out towards the edges.
Continue in the same way with the other adhesive surfaces.
Positioning in relation to the channels in the foam filling
If the heater pad terminates at the channel, position it as illustrated.
Note! The end of the pad must not be up on the flat surface.
If the pad and/or wire in the heater pad is to be positioned in the channel, the pad must follow the foam filling as illustrated. Failure to do so may result in loads to the pad and/or wire that damage the pad. (The type of seam on the upholstery may cause wear in the long term.)
The surface of the heater pad during installation
Caution! There must not be any bubbles or kinks when the heater pad is bonded to the foam filling. Bubbles and kinks increase the risk of damage to the pad during use. This applies to the entire surface, but to the heating wires in particular.
Finishing work after the heater pad has been bonded into place
When the heater pad has been bonded into place the positional straps (shaded in the illustration) must be cut apart. This only applies to those types of heater pads that have positional straps.
Caution! The positional straps must not be cut before bonding is complete.
Installing upholstery
Before securing the upholstery, check the following:
- that any remnants of the half moon clips have been removed
- that the rods (steel or plastic wires in the pockets inside the upholstery) are in position and not protruding outside their pleat. Also check that the rod, or the rod pleat, is not bent and in contact with the heater pad. Adjust if necessary
- that the seam and the rod and pleat are positioned in the channel so that they are not in contact with the heater pad
- that the plastic wires are the correct length and cannot affect the function of the heater pad.
Installing upholstery
Install the upholstery, adjustment knobs and head restraint. See Components backrest, replacing Components Backrest, Replacing (-2002) or Components backrest, replacing Components Backrest, Replacing (2003-).
Testing the bonding
This test can either be performed without the upholstery installed or with partially installed upholstery.
Press at those points illustrated. Check that the heater pad follows the compression of the cushion.
There must be no kinks or other defects in the heater pad when it is pressed.
Testing the function of the heater pad
Start the seat heater and check the function.
Note! The test is not possible if the ambient temperature is too high.
Installing seats
Install the seat. See Front seat, replacing Front Seat, Replacing.