Heated Seat Repair Options (All Range Rover Models)

 

Seats

Introduction
Diagnostics
Official Procedure
Bypassing a Failed Seat Bottom Element
Repairing a Heated Seat Element


Photo: Heated seats on 1996 Range Rover 4.0SE, courtesy of Brian Butler.



Introduction
The heating elements in the seats are a common failure item. When failure does occur, it is usually caused by the heating element in the bottom seat cushion -- while the seat back (squab) element is usually fine. Creative owners are starting to find ways around this problem. One trick is reported below by
Jim Haver, in which he bypasses the bottom seat cushion element so the seat back will still be heated while he saves up for the new cushion!  Other owners have mastered the technique of repairing a damaged heating element inside the seat without repacing anything -- a procedure fully explained and illustrated on our 4.0/4.6 seat heating element repair page.

The present page summarizes diagnostic methods and the various official and unofficial options for dealing with whatever problems you find. The 4.0/4.6 seat heating element repair page
presents full details on the "unofficial" repair procedure that can save a large amount of money.


Diagnostics
Summary:
The first thing to check is whether power is getting to the seat elements (ie fuse is OK etc). To check the condition of the heating elements, you have to find the connectors under the seats -- for connector details see below. Failure of a seat element will usually be an open circuit. You can localize the fault to the cushion or seat back by it by disconnecting the respective connectors and applying an ohm meter to them.When operating normally they should register about 1 ohm. 
Assuming only one seat heater is faulty you can check the correct resistance on the other. Also the seat back should be the same resistance.

Detailed Diagnostics:
(Brett Allison offers the following more detailed diagnosis procedure (he has a 2001 model and in his case the elements turned out to be working but not producing much heat -- for his solution, see the page on "Making your Hated Seats Hotter".)

First, check if the lights in the switches illuminate when you push the heater button on the dash. If they don't, maybe that means the switch is simply bad. I'm not really sure about that.

Next, I would check the continuity of the heater elements in the
seats from the rear and find the two 2-wire connectors for the heater circuits. On my 2001 model, they are white, and the seatseat back heater is the smaller one. They are pretty much the only connectors that you see hanging down when you look under the seat from the rear. (These connectors could look different on other model years). Disconnect the connectors and check the continuity of the heater wires. I found that both the seat back and seatseat back unplugged, the seat bottom would not heat.

If the seat bottom does't have continuity, then I might suspect a bad thermal switch (It may have stuck in the open position -- the bi-metallic disc switches only last so long). But, the heater wire could have broken somewhere, too. In order to go from the rear to the front portion of the seat bottom, the heater wire crosses this channel in the foam in two locations, going down one side then up the other. The seat cover has a metal wire that runs through this channel that gets clipped to a metal wire molded into the foam seat cushion by 5 metal rings. This is how the seat cover is anchored to the foam cushion. I suppose it may be possible for that metal wire in the seat cover to abraid the heater wire as people sit in the seat. Eventually it may wear it all the way through. And, once either of the seat bottom or seat back circuits is broken, the heater will no longer work for the entire seat.


I would also check the connectors themselves. Make sure there is no corrosion, and make sure that good positive metal-to-metal contact is being made. IMO, the connector design isn't that great. I did my best to bend the prongs on the male end a little and pinch the receptacles together on the female end to make sure good contact was being made.


Finally, when the heaters are turned on, I could hear a relay clicking in the big main electrical control box under the passenger seat. Could be a bad relay preventing the seats from working.

 

Official Replacement Method
The official repair method is to remove and dismantle the seat and replace the entire seat cushion.
Replacement of the seat heating elements is a non-trivial task for the do-it-yourselfer, and you will pay around $400 per seat to have someone else do it for you. The procedure is slightly different for pre-99 models versus 99 and up, but in both cases the heating element is part of the seat cushion/foam, and the entire seat has to be removed, dismantled and replaced -- hence the expense for both parts and labor.  The official procedure is well covered in the shop manual.

Procedure for Bypassing the Seat Bottom Element
Jim Haver kindly supplied the following details of the procedure he used to bypass the failed seat bottom element in his Range Rover. This allows him to still heat the seat back.  The details shown here are for the left seat.
Underseat view
First, gather these supplies:

1 inch of electrical tape
1 small paper clip, cut in half to make a U shape

It is helpful to raise the seat to make access beneath easier. Looking from the rear, locate the 3 and 2 pin white connectors (numbered C1401 and C1402 respectively on 1999 - 2002models).

Photo at right
adapted from ETM for 1999 and up models, section Z5, page 34

Disconnect connector C1402, the 2-wire connector with the BLACK and BROWN / GREEN wires going in to it. The female side of the connector comes out of the floor, and the male side is attached to the seat. Insert your custom-manufactured U-shaped jumper, Rand Lover part number PC-01, into the female side of the connector. Make sure both sides of the jumper are in contact with the metal contacts inside the connector. Apply the electrical tape to cover the jumper.

You have just bypassed the seat bottom cushion, and your seat back will now heat.
Image from ETM, section Z5, page 34
{page 453 on the RAVE CD}

Bypassing the right side seat is similar. The connectors look the same. The seat bottom connector has BLACK and BROWN / BLACK wires in it.

This doesn't solve the problem of a broken heating element, but it does restore some bit of comfort until you get around to replacing the seat cushion!


Procedure for Repairing a Seat Heating Element
Classic
Roger Whitbread reports that he actually managed to repair his heating element without replacing it on his Classic Vogue SE.
It was a rather fiddly task, but definitely cheaper than replacement! Roger recounts the following details of the procedure he used:

 

"Carefully remove the leather from the base spring clips. Work from the front & sides. Carefully remove the steel spring pieces if needed or work round them. 

 

Try to locate the break with an ohmmeter working from the underseat connector. The wire is not insulated so you can work along fairly well but it's buried to some extent in a material harness and the foam. You may not locate the exact break, you may have to cut a section out - obviously the shorter the better.

 

Roger used simple in-line crimp connectors to rejoin the wires  - without the outer insulation on the crimp connector."

P38
Jeff Goldman has found that the heating elements on the 4.0/4.6 can also usually be repaired rather than replaced, if you have enough patience. Jeff has kindly provided a fully illustrated procedure for this operation on our Range Rover 4.0/4.6 Heated Seat Element Repair Page.

 


 

 

 

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Page revised February 2, 2012