Electrical question

[Ramhighflyer]

Have an Electrical question: Is there an unused spot in the under dash/drivers footwell fuse box for a switched 15AMP circuit?.. back story, installing aftermarket Rosta seat heaters for the rear, going well, but need a 15AMP switch power supply.. I can pull off the battery and use a relay with trigger, but if there is already something in the cab, that be easier for sure. With the BCM controlling a lot of timers/hot circuits/monitoring AMP draw etc, I just do not want to randomly start splicing into wireing…
Pete

 

[vincentw56]

Have an Electrical question: Is there an unused spot in the under dash/drivers footwell fuse box for a switched 15AMP circuit?.. back story, installing aftermarket Rosta seat heaters for the rear, going well, but need a 15AMP switch power supply.. I can pull off the battery and use a relay with trigger, but if there is already something in the cab, that be easier for sure. With the BCM controlling a lot of timers/hot circuits/monitoring AMP draw etc, I just do not want to randomly start splicing into wireing…
Pete

You can just use a piggyback fuse like most of us have done.

 

[OCD Solutions]

Depending on your trim level, there may be wires in the harness for that feature already and a fuse spot already designated.
Might be worth the time looking for a wiring schematic for your truck and see if you get lucky.

 

[Ramhighflyer]

Depending on your trim level, there may be wires in the harness for that feature already and a fuse spot already designated.
Might be worth the time looking for a wiring schematic for your truck and see if you get lucky.

Yeah, not a bad thought, Laramie with most options, but it’s a ‘21, so I got shorted out of the heated rear seats, and some of the ambient lighting..Covid shortages….. most strange thing is also no Uconnect (telematics), no SOS button etc….. not necessarily a bad thing on that one, just never have seen one without that…
Will do some more looking
Pete

 

[Ramhighflyer]

i just did some looking on a diagram that I have, there are indeed some spots for fuses for the rear seat heaters.in the foot well fuse box….., I presume the wireing is in place, at least upto that point…. Now the next question will be, do you need to “add that option ” with AlphaOBD in order for there to be power at that fuse? Will do some probing….
Pete

 

[OCD Solutions]

It will not have anything to do with Alpha OBD at that point. Insert a fuse and check for power.

 

[Ramhighflyer]

Interesting… found the fuse points for the L&R rear seat heaters, looks to be F20 and F29, what , surprisingly , have fuses in them… Does anyone have access to a wireing diagram?

Would love to see where the wires from that fuseblock end up going? I have a sneaking suspicion that most of the harness is probably there, but that the last little part that ends up connecting the seats to the main harness did not get installed, because of parts shortage… no heated seats … The parts diagrams are not very much help… not sure if the wires end up going thru he center console or heading back thru the door sills…
Will keep digging..
EDIT.. I did find a post of someone trying to add heated and cooled rear seats, and even if there is a connector in the back, it probably will not work, because the seat heat control module is up front… looks like the easiest way to do this is to simply tap the 2 above fuses, run a power wire to the back and go from there, to keep it simple….

On a side note, taking the seat covers off and installing the heating pads is not too bad of a project, just slow and tedious, everything is tight and fits just so… no special parts or tools needed. I just did the Drivers side rear seat so far, look like the Passenger side might be a little more challenging due to the covers being connected with the center seat and console …I do have the 60/40 split bench with reclining function, as well as flip up/down on the seat backs and bottoms.. will report back
Pete

 

[ZombieSlayer]

Here's where the rear heated seat module is if you have one: heated seat switch

 

[FM45]

That PIC shows the front heat module ... under the pass seat... For the rear module, its in the seat back of the drivers side rear seat.... if you pull back the carpeting were the rear seat mounts on both sides, look for a gray plug under the carpet on one side and a black on the other.... if your truck pre-wired you'll find the 2 connectors..

-=FM45=-

 

[Ramhighflyer]

Thanks for the info guys… Soon as I pull the passengers rear seat , I will look to see if there is a plug back there… I did pull the aft cup holders in the center console to see what it is going to take to install the switches…. No extra pigtails there…. In the end , it might be easiest and simplest to pigtail of the existing rear seat heat fuses.(not sure what they are powering?) and run a couple of power wires to the back via the door sills…. The Rosta heaters are self regulating/internal thermostat and do not need anything but a switched + and a ground….
thanks
Pete