Install details for Rostra seat heaters

After having heated seats in my wife's car, we had become spoiled on cool evening and winter mornings.  Riding around with the roof open and the seat heaters on is the only way to go on those cooler days.  Since the Jeep leaves you pretty exposed with the top off, we found that we got too cold for the heater to keep up with once the temps dropped to around 60.  It's fine at low speed, but if you're going over 50, we ended up baking our feet while the rest of our bodies shivered.  It's a Jeep thing, I know...  This spring, my wife asked if we could put seat heaters in the Jeep.  I thought it sounded like a cool idea and looked into the options.  Bestop and Steel Horse make replacement heated seats to the tune of $300+ each.  Unfortunately, they also use replacement brackets that lose the factory "tip-n-fold" features that the seats have.  Other issues included 1.) replacement seats wouldn't match the rear bench (not a big deal), and 2.) our seats were only a year old and in perfect condition.  I hated the thought of replacing perfectly good seats with new ones, so I decided to see what might be available in an add-on seat heater.  After some Google-ing, I found a few companies that make them.  Katzkin (makers of nice aftermarket leather seat kits) sells a seat heater kit, but it is not available direct to consumers.  They only sell to resellers or installers.  The only other companies I was able to find were Rostra and Jacobs Electronics.  I was told that the kits are made by Rostra and rebranded by Jacobs.  Either way, they are the same kit.  Jacobs sells it for $130, Rostra sells it for $100 (Edit: when the CC bill showed up, they only charged me $156 total for both kits + shipping).  Rostra has a house account to sell to individuals.

The kit is pretty basic - 2 heater elements with foam backing and 3M tape on the outer edges of the element side, a plastic control module, wiring harness, switch, main power wires, and a bag of zip ties and wire splices.  I had just installed a waterproof Painless Wiring 7 circuit Cirkit Boss so I wasn't worried about where to tap power or switched leads.  The instructions were pretty clear and from what I could tell, the most difficult part of the install was going to be locating the switches.  Rostra said 1 hour per seat.  I doubled that in my initial estimate and ended up spending twice as long as even I expected... (8 hours for both seats, wiring and switches).

I have used the instructions for seat and seat cover removal from my FSM here.  My narrative and additional suggestions follows each step in the FSM steps.  I've also included pictures that I think will be more helpful for anyone wanting to tackle this.

FRONT SEAT REMOVAL

(1) Disengage seat belt electrical connector (FSM Fig. 1). - This applies to the drivers side only.

(2) Remove the bolts attaching the seat adjuster to the floor panel (FSM Fig. 2).

(3) Remove the seat from the vehicle.

OK, now the seats are out.  Once they are out, you'll need to separate the seat back from the seat base.

FRONT SEAT BACK REMOVAL

(1) Remove the inboard seatback pivot bolt.  - Locate the inboard seat (fig. 1) pivot bolt and remove it with a Torx45 socket.  Be sure to grab the plastic spacer (fig. 2) that goes between the two brackets, noting where it needs to be reinstalled.

(2) Disengage the retainers attaching the cushion cover to the outboard seat cushion frame (FSM Fig. 3). - This is a white plastic strip (fig. 4).  I popped mine off by using a medium screwdriver blade (fig. 5).

(3) Disengage the seat cushion corner cover zipper. - The top part of the zipper is folded between the cover and the corner; pull from the top to feed it back out (fig. 6) and then use a pair of needle nose pliers to unzip it.

(4) Remove the bolts attaching the recliner to the seat cushion frame (FSM Fig. 4). - These are 1/2" bolts and the first one is obvious (fig. 7) once you've unzipped the cushion cover.  The second bolt is located directly below the recliner handle (fig. 8).  I found it easier to hold the handle up while removing this bolt.

(5) Passenger seat and driver dumping seat:

(a) Disengage seat track release cable from back inboard U-nut (FSM Fig. 4). - I found the only way to do this is to remove the cable from the other end  first...  On the bottom of the seat, you will see where the cable mounts to the tip lever after routing through a bracket that holds the cable jacket in place (already removed from the bracket, but not the nipple end in fig. 9).  Once this has been disconnected, you can more easily disconnect the U-nut from the bracket located at the seat pivot point (U-nut still attached in fig. 10).  You can almost see the disconnected U-nut in (fig. 11 and fig. 12).

(6) Route the recliner handle through the seat cushion cover and separate the seatback from the seat cushion. - Self explanatory (fig. 13).  Once this is removed, the seat back will be free from the seat base (fig. 14).

Once the seat back has been separated, it's time to remove the covers and install the heating elements...

FRONT SEAT BACK COVER REMOVAL

(1) Roll cover upward and over tilt release lever. - This part of the FSM is not very accurate...  You'll first need to unfasten the J channel at the bottom of the seat back cover (fig. 15).  You can see how this comes apart in (fig. 16).  Once you have removed the J channel, there will be a plastic fastener still holding the cover at the corner of the frame (fig. 17).  In this shot, it's attached through the white piece of plastic just to the right of my thumb.

(2) Continue to roll cover upward and disengage hook and loop fastener (FSM Fig. 5). - This is the baddest-ass velcro I have ever seen.  It has much smaller hooks and loops and is a lot denser than ordinary velcro.  In (fig. 18), the black strips are the hooks, and the white strips are the loops.  On mine, there were no loops running horizontally across the cover.  (You can see the build date on the seat foam -  3/12/01!)  Be very careful separating the velcro.  It holds so well, you'll need to almost pry it apart to avoid ripping the seat foam.  I tore mine in one spot and used 3M neoprene adhesive to put it all back together.  You can see some discoloration in the seat foam photos due to the spray adhesive.  Once this stuff sets, it's probably stronger than the factory foam.  Just roll the cover up enough to expose the area up to the center velcro.  The seat heater element only covers the bottom 9" on the seat back so complete removal of the cover is not needed.

(3) Passenger seat and driver dumping seat:

(a) Route recliner release cable/strap through cover. - Not needed for this install.  

(4) Separate cover from seatback. - Not needed.

Once you have the cushion exposed enough to place the seat heater element, center the element face down (wires toward the factory cushion and black foam facing toward where the seat cover will be), and remove the 3M adhesive strip on one side (fig. 20).  Press down and peel off the strip on the other side.  The element will now be installed in the seat back (fig. 21).  Reassemble in the reverse of removal.  I routed the wiring between a slot in the J channel (fig. 22).  I notched it out a bit to relieve some of the stress on it where it passes through.  The seat back is now ready to go (fig. 23).

Time to move on to the seat cushion...

FRONT SEAT CUSHION COVER REMOVAL

(1) Disengage inboard J-strap. - Self explanatory (white plastic in fig. 24).

(2) Disengage front J-strap. - Self explanatory (white plastic in fig. 25).  Both J-straps removed in (fig. 26)

(3) Roll cover up to access hog rings. - Before doing this, remove the seat belt attachment bracket (fig. 3 and fig. 27).  Once this is free, roll the rear of the seat cover up to expose the hog rings (small 1/4" loops of wire that wrap around the rods in the foam and frame.   Four hog rings are visible in (fig. 28).  There will be two that hold the cushion to the frame and then two more that hold the cushion cover to the foam.  Hog ring pliers would have been helpful, but I was able to get by using 2 pair of needle nose pliers.

(4) Disengage inboard, outboard and front hog rings. - Don't do this step.  You only need to remove the rear ones and then you can slip the heating element between the foam and the seat cover.

(5) From the underside of the cushion, disengage the rear hog rings (FSM Fig. 6).  - Remove the 2 hog rings attaching the cushion and cover to the frame (fig. 28).  This will allow the seat cushion to come free from the seat frame (fig. 29).  Next remove the 2 hog rings connecting the seat cover to the seat foam (fig. 30).  Now you will be able to reach into the seat cover from the rear of the base.  Miraculously, the space in this area is EXACTLY the same size as the heating element (fig. 30).  Slide the element into the pocket and roll one edge upward.  This will allow you to remove the double sided tape and roll the heating element back into place.  Repeat on the other adhesive strip.  The element will now be installed (fig. 31) and you're ready to reassemble everything.  Reinstall the seat cover using the hog rings and J strips.  Reattach the cable that allows the seat to "tip-n-fold".  The seat bottom cushion is now ready to go (cable still unattached in this photo... fig. 32).

(6) Separate cover from cushion. - Not needed.

Reinstall the seat back to the seat bottom by reversing the instructions.  The only tricky part is reconnecting the "tip-n-fold" cable at the seat pivot area by attaching the U-nut back to it's bracket.  Needle nose pliers are mandatory for this step.  Anything else is too small to grab the U-nut  from within the cavity and re-thread it back into it's anchor.

Next, you'll need to mount the control module for the seat heater.  It's a black plastic box about the size of 2 decks of cards.  Prior to mounting it, you need to make a decision about how you want the heating system to work.  You have 2 choices:

1.) "setting I" on the switch is 140F temperature and only the seatback element is heated.  "setting II" leaves the seatback on and also turns on the seatbase element at 140F.

2.) "setting I" is 135F temperature and turns on both the seatback and seatbase elements.  "setting II" cranks the temperature to 145F on both elements.

The system ships with option 1.) enabled.  To get it to work as described in 2.), you need to snip a blue loop wire that hangs outside the control module.  I opted for 2.) and snipped the wire.  The module can be easily attached to the bottom of the seat cushion by using zip ties.  Make sure to position it such that it won't interfere with any springs, levers, or cables (fig. 33).

Now that the seat hardware is installed it's time to move to the switches and wiring...

The Rostra install manual suggests locating the switch in the plastic surrounding the seat base.  That's a great suggestion as long as we're not talking about a Jeep seat.  Not an ounce of plastic trim to attach to...  I wanted somewhere central but out of the way.  After looking at a bunch of possible choices, I selected the console, just ahead of the e-brake.  You need to end up with a 13/16" hole and about 2" of clearance behind the switch.  This part of the console has plenty of clearance between the console and the shifter.  I checked the clearance before drilling by removing the shift boot and seeing how far back the shifter is located in 2nd, 4th, and Reverse.  After checking the locations, I drilled 3/4" holes with a forsner bit.  This gave me a nice clean cut that was almost large enough.  I used a round file to get the last 1/16" opened up and press fit the switches into the console (fig. 34).  I was worried they would be flimsy and wobble, but they are very solid and looks almost like it came from the factory that way...

For the wiring runs, I wanted everything routed toward the center of the Jeep, so I wouldn't be stepping on anything.  Fortunately, the seat riser brackets have a nice gap in them between the bottom plate and the floorboard about 2" long and tall enough to route the wiring looms through.  This is also the area where the carpet is separated for easy removal, so it's easy to tuck the looms up under the carpet and console.  From there, I routed the looms behind the t-case lever and the shifter (fig. 35), eventually holding the looms in place with zip ties.  At the front edge of the shifter, I pulled out the ground wires, attached loop ends on them and secured them to an existing ground point (fig. 36).  The rest of the power wiring (constant hot and switched) was run in a loom across the firewall where my aux. power connections enter the tub.  I ran each of the hot draw leads (drivers side and pass. side) to their own separate 20A circuit (fused with the Rostra inline 10A on the tub side of the firewall).  I ran the 2 ignition hot wires to a common 20A switched feed.

Wiring the switches was the only thing left.  Unfortunately, the switch harness is not long enough to reach from the console back under the seat to the control module.  I snipped the switch harness and extended the wires about 3'.  I soldered, taped, and shrink wrapped the splices on the extended wires (fig. 37).  The gap between the seat riser and the floorboard is evident in this photo as well.  You can see the plastic conduit that houses the power wires as it runs under the riser, then into the carpet and console.

Reassemble everything, double checking as you go to make sure you didn't leave loose connections or wires that will get caught (zip ties are your friend).  Step back and admire the installed product (fig. 38).  Not much to see, but once they're cooking, it's fantastic...

Reattach the battery, make sure nothing smokes or blows a fuse and you're ready for the maiden voyage...

The seats start to warm to the touch in less than 2 min and after about 5 min. they are very toasty.  10 min seems to be needed before they are at full operating temperatures.  I found setting "I" was fine for me, but my wife liked the super heating of "II".  We cruised around after dark when the temps were in the low 60's.  Having the seat heaters made a big difference.  I may never put my soft top back up now!  The elements are really beefy and the control module is a tidy circuit board and relay combo.  The control module cycles the power to the elements once they reach their operating temperature.  This prevents them from staying on continuously and they can be used all the time if you desire.  Rostra provides a 3 year warranty.  

This could definitely be considered a frivolous mod, but it made the wife really happy and I had fun doing it.  Drop me a line if you have any questions...  Cost $160 - 2 seat heater kits with shipping; time to install 8 hours for both seats (I'm a slow worker...).

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