Fitting Mondeo with Heated Front Seats - Mk2

Fitting Mondeo MK2 with Heated Front Seats

I now have working heated front seats in my LX mondeo.

Background

Heres how it was done... (takes about 2 hours if the seats are already fitted, longer if you have to fit them) Basically, ive used the wiring diagram from a mk1 mondeo td haynes manual, which is about the same as the mk2 (all be it that the switches are in a different place, but still works the same). Ive identified the colour codes of the wires at the different connections in the car, and hopefully all will be the same.

Parts

The bits you will need before I continue, are...

Heated front seats (preferably fitted in the car). Wiring looms that connect the seats to the car (hopefully you will have these, but it is possible to fit without) Heated seat switches (fit under the stereo in place of the stupid tape holder thing) A relay holder (the heated seats one is excellent, but any one which holds a brown relay will do) The 2 plugs for the switches, with as much wire on them as you can get (probably from a scrap car if you don’t already have them fitted) A brown relay (the fuesbox under the bonnet is full of them) The correct relay number is 96FG 14N089 AA its brown with a red tint. A picture of this can be seen below:

If the looms are not already in place, you will need about 7m of single core cable, which needs to be about 7.5 amps. Hand full of different bullet connectors, scotch clips etc (and tools to fit them to wires) I used a soldering Iron, and some insulation tape, but I guess you could use other things to do the same job.

Method and Wiring

The wire colours etc are as follows:

The brown relay (assuming its in a holder from a car with heated seats) • Orange + Yellow > Auxiliary fuse box, F8 (which is supposed to be the main + feed. Any good positive feed should do this) • Blue + Red (thick) > Seat switches > R/H Blue + Black, L/H Blue (they all join together) • Black > Earth • Blue + Red (thin) > Switched +ive ignition (i.e. on when ignition on, off when ignition off)

L/H Heated Seat Switch • Black > Earth (connected together with the earth from R/H switch – I took this from the radio) • White > Interior lighting (i.e. +ive when sidelights/headlights are on – I took mine from the radio) • Blue > Seat relay, joins R/H switch (see above) – which is Blue + Red at the Relay • Blue + White > L/H seat heater (wiring under the seat) – wire under seat is also Blue + White.

R/H Heated Seat Switch • Black > Earth (connected together with the earth from L/H switch – I took this from the radio) • White + Red > Interior lighting (i.e. +ive when sidelights/headlights are on – I took mine from the radio) • Blue > Seat relay, joins L/H switch (see above) – which is Blue + Red at the Relay • Blue + Orange > R/H seat heater (wiring under the seat) – wire under seat is Blue + White.

L/H Seat Heater under L/H front seat • Blue + White > L/H Seat heater switch • Black > Earth

R/H Seat Heater under R/H front seat • Blue + White (possibly blue + orange) > R/H Seat heater switch • Black > Earth

Below is the wiring diagram for this project:

If you can make sense of this, then wiring the lot in should be a doddle. Noting the following points:

I don’t know where the loom goes from the under side of the seat (if the connectors are present, so I connected the relevant wires from the switches under the seat (made the earth by securing a wire to the screw that holds the plastic cover over the seat runners) I didn’t fit my seats with the fuse (as it wasn’t present) so took my permanent live from the fuse box under the dash (the one behind the glove box), there was an orange thick wire here, that I used (hey it works!) I fitted the relay behind the switches, using the lighting supply from the radio, and the radios earth for the relay, made fitting it easier, used less wire. The lengths of wire above, are really needed to get the supply to the relay, and from the switches to the seats (there are 2 lengths about 2.5m long – one to each front seat, and 1 about a metre long to get the live to the relay from the fuse box. I then used 2 bits about half a metre long for the earth to the seat heaters).

Submitted by wilkobob Relay image by guardtower