Illustrated
Details of Heated
Seat
Element Repair
(Range Rover 4.0/4.6/P38)
Introduction
Overview of Repair Operation
Tools Required
Disclaimer and Warning
Diagnostic Testing
Dismantling and Repair Procedure
Input From Other Owners
More Information
Introduction
Jeff Goldman reports that repairing the heated seats of a P38 is easier than you might expect, but the job requires a bit of patience. This page covers Jeff's detailed instructions and photos uillustrating seat removal and heating element repair on the driver's seat (LHD) of a 1999 Range Rover Callaway, which actually conforms more to the spec and workshop procedure of a pre-'99 model year P38. The steps for a MY99+ P38 should be fairly similar.
This guide also only covers the repair of the seat bottom element since this was the only one in disrepair on my vehicle. You're on your own with the seat back element, but this will get you half way there.
The official heating element repair as recommended by the Land Rover shop manual is complete replacement of the foam seat of the cushion, since the element is an integral part of the foam cushion. This is only partly true, and later steps illustrate how the element is actually integrated into the foam and how to get around replacing the entire cushion, if desired. Of course, the option exists to heed Land Rover's advice and replace the cushion if you're not comfortable with the electrical work.
For more information on heated seat diagnosis, repair and replacement, see the main heated seat problems, diagnosis and repair page.
Overview of Repair Operation
Steps happen in the following basic order:
Removal of seat from vehicle
Removal of seat base
Separation of seat back from seat bottom
Removal of seat frame
Removal of seat cover
Diagnosis and repair of heating element
Reverse steps to complete repair
This repair can take some time, but depending on your patience level (and weather) can be well worth it. Count on at least a couple of hours for the single seat. By far the fiddliest bits involve the removal of the seat cover clips and hog rings. The actual removal, breakdown of the seat, and element repair takes minutes, in comparison. (Photo: The repair virtually pays for itself! This was found under the driver's seat upon removal).
Be sure to have the right tools on hand before beginning, particularly if you've taken out the driver's seat and do not have an alternative means of transportation to the local hardware store. I practised on my passenger side seat before committing to disabling my principal means of transportation for a few hours. It's lucky I did!
Tools Required
Assortment of screwdrivers (Slot and Philips)
Two needle nose pliers for the hog rings (I had great luck with a regular narrow nose and a bent nosed)
Wire cutters
Sharp knife (X-acto)
T40 Torx/Star driver (this needs to have a long reach)
T45 Torx/Star driver (I use a 3/8" rachet and T45 socket driver)
Soldering iron
Electrical solder
20-14 gauge wire (about 4")
Butt crimp connector (preferably without insulation; x2)
Voltmeter with continuity or resistance capability.
The Torx/Star bits are a necessity! As are two sets of needle nose pliers that can grip.
Disclaimer and Warning:
I always recommend utilizing the Official Land Rover Workshop when undertaking any repairs on your vehicle. This guide should be used as reference to the workshop procedure. You are on your own with this repair as it involves messing with a safety related part of the vehicle. You'll have to remove the seatbelt lower mounting and contend with any side curtain SRS issues. If you're uncomfortable with electrical repairs, I would recommend cushion replacement rather than element repair.
Diagnostic Testing
Disconnect the two heater element plugs under the front seat (two connectors each), and probe the contacts for continuity. A continuous, working circuit will read around 1.0 ohm. An indication of 0.0 indicates a break in the element somewhere. Chances are the seat back circuit (smaller connector) will be OK, but the seat bottom (larger connector) will register null.
Dismantling and Repair Procedure
At this point the easy part is over. Separating the seat cover from the seat foam requires the removal of several metal hog rings that run down the sides and middle of the seat cushion. Once you master the technique of prying one hog ring open and out, the others become much easier. The basic strategy is to rotate the ring with needle nose pliers so that you can see the two ring ends, then grab the ring with two sets of pliers and widen the opening allowing the ring to be removed. Remove the rings from the two sides first, and remove the two guide wires that run down the length of the cover by prying open the loops on one end and sliding them free. This will allow you to fold the cover in half to allow access to the lateral seam rings. Once all the rings are out the cover will simply lift off.
HAVE PATIENCE. IT BECOMES EASIER AS YOU GET USED TO IT. REPLACING THE RINGS IS A BIT EASIER THAN REMOVING THEM. THIS IS BY FAR THE HARDEST PART OF THE REPAIR PROCEDURE!
Congratulations! You can now choose to replace the entire cushion, as Land Rover recommends, in which case reverse the removal steps and you are done! Or, read on if you want to troubleshoot your existing element.
If your problem does not exist in this common location, troubleshooting becomes a little harder, but not impossible. Read below to see how I should not have started looking for the break, but how you can gain greater access to the entire heater matrix, if necessary!
If you've reached this far and all is well, then just reverse all the steps to get back to the beginning! Re-attaching the hog rings is a bit tricky, but not as bad as removing them. Again, work carefully and with patience and you'll be rewarded with working seat heaters for very little investment, if any.
Input from Other Owners
David Blasingame reports: "I followed Jeff Goldman's guide to repair/replace the heated seat on my 1996 4.0 RR and it was absolutely wonderful. His directions were spot on, and he was right about the hog rings. My problem turned out to be two broken wires where they jump from the back to the front of the seat. I simply soldered in a jumper wire of a slightly heavier gauge, and I'm back with a toasty rear-end. Just thought I'd support his walk-through and say its a wonderful guide".
More Information
Main Seat Heater diagnosis and repair page
Making the seat heater hotter.
(Range Rover 4.0/4.6/P38)
Introduction
Overview of Repair Operation
Tools Required
Disclaimer and Warning
Diagnostic Testing
Dismantling and Repair Procedure
Input From Other Owners
More Information
Introduction
Jeff Goldman reports that repairing the heated seats of a P38 is easier than you might expect, but the job requires a bit of patience. This page covers Jeff's detailed instructions and photos uillustrating seat removal and heating element repair on the driver's seat (LHD) of a 1999 Range Rover Callaway, which actually conforms more to the spec and workshop procedure of a pre-'99 model year P38. The steps for a MY99+ P38 should be fairly similar.
This guide also only covers the repair of the seat bottom element since this was the only one in disrepair on my vehicle. You're on your own with the seat back element, but this will get you half way there.
The official heating element repair as recommended by the Land Rover shop manual is complete replacement of the foam seat of the cushion, since the element is an integral part of the foam cushion. This is only partly true, and later steps illustrate how the element is actually integrated into the foam and how to get around replacing the entire cushion, if desired. Of course, the option exists to heed Land Rover's advice and replace the cushion if you're not comfortable with the electrical work.
For more information on heated seat diagnosis, repair and replacement, see the main heated seat problems, diagnosis and repair page.
Overview of Repair OperationSteps happen in the following basic order:
Removal of seat from vehicle
Removal of seat base
Separation of seat back from seat bottom
Removal of seat frame
Removal of seat cover
Diagnosis and repair of heating element
Reverse steps to complete repair
This repair can take some time, but depending on your patience level (and weather) can be well worth it. Count on at least a couple of hours for the single seat. By far the fiddliest bits involve the removal of the seat cover clips and hog rings. The actual removal, breakdown of the seat, and element repair takes minutes, in comparison. (Photo: The repair virtually pays for itself! This was found under the driver's seat upon removal).
Be sure to have the right tools on hand before beginning, particularly if you've taken out the driver's seat and do not have an alternative means of transportation to the local hardware store. I practised on my passenger side seat before committing to disabling my principal means of transportation for a few hours. It's lucky I did!
Tools Required
Assortment of screwdrivers (Slot and Philips)
Two needle nose pliers for the hog rings (I had great luck with a regular narrow nose and a bent nosed)
Wire cutters
Sharp knife (X-acto)
T40 Torx/Star driver (this needs to have a long reach)
T45 Torx/Star driver (I use a 3/8" rachet and T45 socket driver)
Soldering iron
Electrical solder
20-14 gauge wire (about 4")
Butt crimp connector (preferably without insulation; x2)
Voltmeter with continuity or resistance capability.
The Torx/Star bits are a necessity! As are two sets of needle nose pliers that can grip.
Disclaimer and Warning:
I always recommend utilizing the Official Land Rover Workshop when undertaking any repairs on your vehicle. This guide should be used as reference to the workshop procedure. You are on your own with this repair as it involves messing with a safety related part of the vehicle. You'll have to remove the seatbelt lower mounting and contend with any side curtain SRS issues. If you're uncomfortable with electrical repairs, I would recommend cushion replacement rather than element repair.
Diagnostic Testing
Disconnect the two heater element plugs under the front seat (two connectors each), and probe the contacts for continuity. A continuous, working circuit will read around 1.0 ohm. An indication of 0.0 indicates a break in the element somewhere. Chances are the seat back circuit (smaller connector) will be OK, but the seat bottom (larger connector) will register null.
Dismantling and Repair Procedure
Step 1SEATBOX COVER REMOVAL - Remove the seat box cover by removing the four plastic rivets. There is one large rivet at the front, and three along the side. They can be tricky, but are designed to be pulled out. On the passenger side (LHD) there are three rivets and one screw behind the fusebox door. |
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Step 2:SEAT BOLT REMOVAL - Raise the seat to its highest position. Using a T45 Torx/Star bit, remove the four bolts that secure the seat to the seat box brackets. There are two at the front and two at the rear under rubber covers |
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Step 3:<>SEATBELT BRACKET REMOVAL -Remove the plastic cover protecting the lower seatbelt mounting bolt at the bottom of the seat, and lift out the seatbelt bracket. On pre-99 models, this involves lifting a springloaded plug and sliding the bracket off the bolt. |
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| <>Step 4: UNDERSEAT CONNECTORS - Be sure the seat is at its highest position before disconnecting the power connector to the power seat system. This can be found as the center white connector on the electrical box mounted under the seat. Access may be easier from the rear. Disconnect the two power connectors running to the seat heater elements. These are two-wire connectors, one smaller than the other. The image shows black electrical tape over the seat bottom connector as a result of temporarily implemeting the paperclip bypass method to retain heat to the seatback. Disconnect the seatbelt warning buzzer at the rear of the seat. This should cover everything connected between the seat and vehicle, and the entire assembly can be removed from the vehicle through the front door. |
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Step 5:
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| <>Step 6: SEAT BASE REMOVAL - Four T40
Torx/Star bolts hold the seat to the seat
base assembly. Use a long T40 bit to remove the two bolts under the
front of the seat and the two bolts angled at the rear. My 3/8" T40
socket bit would not fit under the seat for the front bolts,
necessitating a trip to the hardware store to purchase a longer wrench.
Luckily, it was my passenger seat I discovered this on! |
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Step 7: SEAT BOTTOM SEPARATION - The seat back is secured to the seat base by three items that must be removed or disconnected. First, remove the little metal clips at the rear corners securing the seat cover to the seat base (D). Second, the seatback cover attaches to the base of the seat via a length plastic clip. This is one of the fiddliest bits to remove and actually covers a similar clip used to attach the bottom seat cover to the seat base (A). This will be the start of your test in patience! Once the cover flap has been released, remove the four T45 Torx/Star bolts from the side brackets (C). The upper part of the seat should separate, with brackets, from the bottom cushion. Though not necessary, sometimes removing the two C-shaped steel clips (B) can help with access, but not much. |
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Step 8:
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At this point the easy part is over. Separating the seat cover from the seat foam requires the removal of several metal hog rings that run down the sides and middle of the seat cushion. Once you master the technique of prying one hog ring open and out, the others become much easier. The basic strategy is to rotate the ring with needle nose pliers so that you can see the two ring ends, then grab the ring with two sets of pliers and widen the opening allowing the ring to be removed. Remove the rings from the two sides first, and remove the two guide wires that run down the length of the cover by prying open the loops on one end and sliding them free. This will allow you to fold the cover in half to allow access to the lateral seam rings. Once all the rings are out the cover will simply lift off.
HAVE PATIENCE. IT BECOMES EASIER AS YOU GET USED TO IT. REPLACING THE RINGS IS A BIT EASIER THAN REMOVING THEM. THIS IS BY FAR THE HARDEST PART OF THE REPAIR PROCEDURE!
Congratulations! You can now choose to replace the entire cushion, as Land Rover recommends, in which case reverse the removal steps and you are done! Or, read on if you want to troubleshoot your existing element.
Step 9: HEATER ELEMENT DIAGNOSIS -
The heating element is merely
a squiggle of common, stranded insulated copper wire (see photo for
Step 11). The thin gauge
causes high resistance so that electricity travelling through the
circuit ends up as heat.
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Step 10: ELEMENT REPAIR WITH JUMPER - You could just butt connect the broken wires together to complete the circuit again, but I'd lay odds that the same problem would rear its head in the future. To prevent the same occurance from happening I decided to add a thicker gauge jumper wire between the break. I ran the repair underneath the wire that secures the seat cover to the foam for added protection, and used a combination of crimp connecting and soldering to ensure a solid connection. Though you can't see it, I also covered the bare connector with heat shrink tubing to tidy things up. The crimps themselves were made from regular 18 gauge automotive butt connectors cut in half and de-insulated. |
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If your problem does not exist in this common location, troubleshooting becomes a little harder, but not impossible. Read below to see how I should not have started looking for the break, but how you can gain greater access to the entire heater matrix, if necessary!
If you've reached this far and all is well, then just reverse all the steps to get back to the beginning! Re-attaching the hog rings is a bit tricky, but not as bad as removing them. Again, work carefully and with patience and you'll be rewarded with working seat heaters for very little investment, if any.
Step 11: RECOVERY IF HEATING WIRE SPRINGS OUT- It is true that the heating element is integrated into the seat cushion foam, but as you can see, this can be worked around quite readily. The top layer of foam is only lightly secured to the main cushion foam. Remove this layer, and you gain full access to the element matrix. HOWEVER, check the middle lateral crease area first! I pulled the foam apart before discovering the break at the crease, and I would never have had to deal with the mess of wire under the foam had I checked there first! If you happen to find yourself in the boat I was in, just be patient and careful. Lay the heating element wire back in place (use masking tape temporarily, if necessary,) and secure the top layer of foam back in place using a light coating of spray adhesive (3M 77, for instance.) WARNING: I don't know how the adhesive will react to the heat of the element, but so far I have not noticed any ill effects such as smoke or a strange odor... or fire. |
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Input from Other Owners
David Blasingame reports: "I followed Jeff Goldman's guide to repair/replace the heated seat on my 1996 4.0 RR and it was absolutely wonderful. His directions were spot on, and he was right about the hog rings. My problem turned out to be two broken wires where they jump from the back to the front of the seat. I simply soldered in a jumper wire of a slightly heavier gauge, and I'm back with a toasty rear-end. Just thought I'd support his walk-through and say its a wonderful guide".
More Information
Main Seat Heater diagnosis and repair page
Making the seat heater hotter.