[Barry King]

I decided to tackle installing a Katzkin leather kit, and while I was at it, also installed seat heaters in both front seats and the rear seats, too. These seat heaters are the typical kit you can buy on eBay that comes with a back pad and seat pad wired to a harness with an on/off switch, red power line, black ground line, and a fused jumper. I know I can connect all black wires together and hooked to the same ground. What I don't know is, am I able to connect all 4 power lines (from all 4 sets) together and hook up to the same ignition power (as opposed to the battery since I want to be certain the power is cut when the key is out). Along those same lines...does each power line need to be fused separately, or can they all be hooked to the same fused jumper?


On another note, what the hell is this under the passenger seat?

 

[tslave]

That's your Bluetooth module under the passenger seat. No idea about the seat warmers.

 

[dubyam]

What are the pads rated to draw at max? If it's low enough, and the wiring is sufficient for the current, you could tie them all together and run them to an add-a-fuse with the appropriate fuse in it, on a switched location in the fuse box. For reference, if the wires are 16ga, the total power feeding capacity will be about 3.5a. Move up to 14ga, and the capacity grows to about 5.5a. I highly doubt the wiring is bigger than 14, but maybe. If it's 12ga, you could run a load of 9a safely. The grounding capacity of these is far higher, so no need to worry over that side.

If you tied them together with bigger gauge wire capable of carrying the full load for all four heaters, as long as the existing harness off the heaters is sufficient to carry the load for one heater, you could put them all on a single circuit. Just be sure you use good connections and isolate them well. Heaters are resistive and will draw a fair amount of power and generate a good bit of heat (duh! Heaters generate heat...) so wiring is a key here.

A quick check of the eBay seat heaters shows them all ranging from 4-5a draw, based on a 12v circuit, per seat (2-2.5a per pad). So you will need at least 12ga wire to tie them all together, and 10a would be better to avoid potential electrical fires. Each pad would only need 16ga wiring from the tie-in to the individual pad. Now, if your pads are rated for something other than 48-60w per pair, the equation changes.

 

[Barry King]

Based on a youtube video I saw of the same pads, on low setting, each set of pads draws about 2.0-2.5 amps...on high setting, each set draws right at 5.0 amps.

If I understand you correctly, I could tie all ground wires together, and ground them on a single grounding location. I could also tie all red power wires from the 4 sets of heaters together and connect to a single 10ga wire and then tie into a single IGNITION fuse with an Add-a-Fuse. If each warmer set draws a max of 5.0 amps, does that mean I need a 20 amp fuse?

 

[Nick Name]

Amps are amps. If you bundle one side of the circuit such as the hot side and determine a larger gauge feed wire is necessary, then the same rules for the ground side if bundled. That didn't seem to come out very clearly in the other posts. Now, the $64,000 question: what is the probability that all circuits would be on Hi at the same time? All circuits on any setting at the same time? You may have an easier install separating front and rear into two circuits attached to two separately fused points of origin.

At 5.0 amps times 4 circuits a 20 amp would blow if there was any wiggle in the specs of either the pads or the fuse. A thirty would be a better choice, but me, I'd go for two separate 15 amp circuits.

 

[Barry King]

Thanks, tslave, dubyam and Nick Name!!! Electricity has always been a mind-boggler for me. I sincerely appreciate all of your input, and I think I'll take your final suggestion, Nick Name, and split the front and back between 2 circuits.

 

[Smccarty3]

There's nothing better than having a reply all wrote out and the phone goes blank from inactivity for a minute and lose it all. Anyway I'll try again. I would use a relay to trigger the 12v power to the seat switches. You could use any 12v ignition triggered power source, that way they would only have power while the ignition was on. I want to keep an eye on this thread as I have neoprene seat covers and thought about throwing a set between those and the seats. I don't know if that's even a feasible idea, but they are a nice feature when it's cold.

 

[Barry King]

Back to showing my ineptitude...

Smccarty3, you mentioned using a relay...there is a relay "built in" to the wiring kit that comes with the seat warmers as you can (barely) see in my first photo. Does this relay satisfy the setup suggestion you had in mind?

 

[Smccarty3]

Yes the supplied relay should work fine. Sorry I didn't see it in t h e pics.

 

[jdmartin]

I would like to see you document this thing with pictures!

 

[Barry King]

I would like to see you document this thing with pictures!

Screwed the pooch on the first part of that one, as I've already finished installing the front seat warmers (minus the whole electricity part) and leather upholstery. I'll do a better job of documenting the process for the rear seats, electric runs and connections, and final outcome.

 

[Barry King]

I'm still in the middle of this "couple of hours long" project. I've got the heating pads and leather seats installed, but I want to be smart about where I wire these seat heaters into. After the suggestions above, I decided to write the 2 passenger-side (front and rear) seat heaters together, and then wire the 2 driver-side (front and rear) heaters together. As noted above, the heaters come wired with a relay (for each seat), followed by the switch wires (bundled and harnessed), as well as 16g power and 16g ground wires. On the passenger side, I connected the 2 16g ground wires and then connected those to a short 10g wire that was grounded to the bare bolt holding the front passenger seat belt in place behind the plastic cover. The 2 16g power lines were then connected to a run off 10g wire that I plan to connect via Add-a-Fuse connection in the passenger side fuse box.

ALL THAT just to ask the following question: where should I connect the 2 driver-side heaters to if I want them to only receive power when the key is in the run position? I don't want full time power because I have 2 kids, and well, I'm a guy, so I know 1 of the 3 of us will leave the things on.

I've included a couple of pictures that may help me understand any of your suggestions in case they include the wiring under the steering column/ignition.

 

[dubyam]

You just need to wire everything to a switched circuit. You can still use the add a fuse, and simply add it at a location in the fuse box which is switched. Think about stuff which won't turn on when the truck is off (so not cabin lights, bells/chimes, etc.).

 

[Barry King]

I looked at the passenger side fuse box labels, and there are 2 fuses already installed for front and rear seat heaters despite my truck not having those heaters. Am I crazy to think that I could just run my power lines to each of those 2 fuses, and be good? If so, what's the easiest way to connect my 10 gauge power wires to those fuses? I've seen online the blade type of "adapter/connector" that essentially contours one of the legs of the existing fuse when reinserted. Is this what I need to look for, is there a better way to tap into the existing fuse, or is the Add-a-Fuse still the best way to go despite not really "adding to" the current fuse/circuit?

 

[Nick Name]

Look at a Titan wiring diagram to find the wire colors and pattern (stripe etc.) More than likely, the wires you need are already run to where you need them and they terminate in a multi-wire plug. I would be surprised if there were more than one wire harness used in building these trucks.

 

[Smccarty3]

The only problem with using the power from the harness would be its probably set up to be switched and you don't have factory switches. I would use the add a fuse in their spot.

 

[Nick Name]

his photo in the orig post shows the factory style rectangle pop in switch that fits the standard dash opening. it will work just fine...he wants it switched. what doesn't show is whether they're the double switches or single. double would only require two openings to run all four seats. single ...he needs four openings and I don't know where he'll find that many vacant inside his truck.

 

[Barry King]

Here's a sketch of the locations of switches and wire runs. Each set of pads has its own High/Off/Low switch. The attached pictures show the exact set of pads and switch. With everything run to it's desired location, the only thing left to do is hook up the positive lines to fuses and then to power. I THINK my last question is this... if the Add-a-Fuse wire is 16 gauge, wasn't it a waste to connect the 16 gauge power and ground lines up to 10 gauge since the line is going to step back down to 16 gauge before entering the fuse?

 

[Nick Name]

if hooking up to the already fused factory wires, the extra fused link could be eliminated. The wire gauge of 10 to 16 is ok. If it was the other way around....that's a problem.