Where to connect seat warmers?

David,
They should include relays and switches already wired to the elements.
The hot terminal on the relay (term 30) needs to go directly to a high amperage B+ supply (hot all the time). 2 locations that are accessible are direct to the 12v battery and to the front engine compartment fuse panel (under the red cover for the "jumper terminal"). Use 12 gauge wire and put an inline fuse (around 20-25 amps) close to the power source. Make sure you have a good solid ground also with 12 ga wire. There should be another power input for the switch (relay control) that should go to an Ignition controlled power source. One of the lighter outlets would be fine to tap into for this because the relay uses 1/2 amp or less. You will want the system to turn off when you shut down the car. The relay will need a ground also for the coil. If your system doesn't have these components, send a copy of the instructions or a pic of the wiring.
Hope this helps.
Bob C.

 

Try to find some that have all the switches and relays supplied with the kit. Some might also have a timer circuit that turns them off after a set time interval just to conserve power as the cabin warms up. I'm not much of an expert on the heater kits, having lived in the south all my life. My previous trailblazer had factory seat heaters and I actually got to use them 2-3 times in 2 years in S FL. I see why they are on your must have list in NY.