It took me a while to compile all the information for this swap, so I figured I'd share. I just finished it in my 2012 Mustang GT Premium, no nav, manual climate control. I purchased pullout factory heated seats. It works flawlessly. I made a couple of decisions to simplify the install, but I outline both the correct circuits, and what I ended up doing.
If you have different vehicle options, do your own research and as always..... proceed at your own risk!
Note the heat only comes on when the car is running.
List of what you need:
Wiring diagram for your mustang(optional but strongly suggested). Its very handy to have for troubleshooting. I'll try to post the ones that are useful.
Heated seats - If they are factory, the passenger side will also be full power adjustable, so you get a twofer. If they are not factory, you will have to provide your own relays, as the factory relays are under the drivers seat. You can still use the factory buttons, and all the hardware is still needed. Use the electrical diagrams to figure out how to connect.
Radio Button Bezel with heated seat buttons. This will be different depending on your options. Here is mine....
HVAC control module cr3z19980d(or equivalent) - This will be different if you have the dual climate control. It is the black box located behind the radio bezel. There was a thread that said you don't need this if you have forscan...but I didn't take the time to figure it out. My guess is that, since I didn't need forscan, the circuit for the buttons isn't in the no heat box.
Connectors from junkyard/ebay/marketplace
2 under seat wiring pigtail and connectors(C300 or C311) from the body harness (Will need a total of 5 of the big pins, 3 little pins). If junkyard hopping, make sure when you grab them that they have the 4 big pins populated. If the car didn't have heated seats, it won't have the pins.
This is what they look like. Big pins are on the 4 corners. Little pins in the middle. Match up the wire gauge, as there is one big pin that has a small wire. DON'T use this small wire for the heat or motor circuit. If you need to use it, solder a bigger wire to the pin.
Pigtail and connector(C294A) that plugs into the climate control module . (Need 2 pins from this connector). This is plugged into the black box(HVAC Control Module) located behind the radio bezel. It is where the heat button signals come from.
I bought my connectors off of Ebay(Expensive, but I don't have time to wander junkyards). They don't necessarily have to be from a mustang, just a ford. Mine came from a Mustang, an Escape, and an F150. You can match up the pictures to make sure you get connectors with the right pins.
You will need to pull the wires and pins from these connectors. Note that on both style connectors, the slightly yellow piece pops up. You can remove it to see how to get the pins out, however when you install the pins in the car connector, you need to pop it up(don't need to remove) to install the pins.
General Info
The relays are located under the driver seat(if factory), one for each seat.
The connectors below are denoted with a Cxxxx. This is in the electrical diagrams.
You will need 14ga wire, 16ga wire, and 20ga wire(3 colors to make it easy).
Note you do NOT need forscan for this modification
Connection Info
Power
I did not use the heated seat circuits for the power. Since the passenger seat also had power motor adjustment, I needed to run a power wire for that too. This is a 30A circuit, which is more than enough to do both the power and the seats, so I used it for both.
Heated seat power.
Other helpful links
https://www.allfordmustangs.com/threads/heated-seats-hvac-module-tech-repair-help.285483/
https://themustangsource.com/forums/f803/add-oem-heated-seats-540050/
https://themustangsource.com/forums/f803/adding-oem-heated-seats-2012-gt-premium-542820/
I probably won't check this post much. I had a pdf with the wiring diagrams, but it is too big to upload. I'll try to post diagrams later.
I hope you enjoy the warm buns on a cold day as much as I do!
If you have different vehicle options, do your own research and as always..... proceed at your own risk!
Note the heat only comes on when the car is running.
List of what you need:
Wiring diagram for your mustang(optional but strongly suggested). Its very handy to have for troubleshooting. I'll try to post the ones that are useful.
Heated seats - If they are factory, the passenger side will also be full power adjustable, so you get a twofer. If they are not factory, you will have to provide your own relays, as the factory relays are under the drivers seat. You can still use the factory buttons, and all the hardware is still needed. Use the electrical diagrams to figure out how to connect.
Radio Button Bezel with heated seat buttons. This will be different depending on your options. Here is mine....
HVAC control module cr3z19980d(or equivalent) - This will be different if you have the dual climate control. It is the black box located behind the radio bezel. There was a thread that said you don't need this if you have forscan...but I didn't take the time to figure it out. My guess is that, since I didn't need forscan, the circuit for the buttons isn't in the no heat box.
Connectors from junkyard/ebay/marketplace
2 under seat wiring pigtail and connectors(C300 or C311) from the body harness (Will need a total of 5 of the big pins, 3 little pins). If junkyard hopping, make sure when you grab them that they have the 4 big pins populated. If the car didn't have heated seats, it won't have the pins.
This is what they look like. Big pins are on the 4 corners. Little pins in the middle. Match up the wire gauge, as there is one big pin that has a small wire. DON'T use this small wire for the heat or motor circuit. If you need to use it, solder a bigger wire to the pin.
Pigtail and connector(C294A) that plugs into the climate control module . (Need 2 pins from this connector). This is plugged into the black box(HVAC Control Module) located behind the radio bezel. It is where the heat button signals come from.
I bought my connectors off of Ebay(Expensive, but I don't have time to wander junkyards). They don't necessarily have to be from a mustang, just a ford. Mine came from a Mustang, an Escape, and an F150. You can match up the pictures to make sure you get connectors with the right pins.
You will need to pull the wires and pins from these connectors. Note that on both style connectors, the slightly yellow piece pops up. You can remove it to see how to get the pins out, however when you install the pins in the car connector, you need to pop it up(don't need to remove) to install the pins.
General Info
The relays are located under the driver seat(if factory), one for each seat.
The connectors below are denoted with a Cxxxx. This is in the electrical diagrams.
You will need 14ga wire, 16ga wire, and 20ga wire(3 colors to make it easy).
Note you do NOT need forscan for this modification
Connection Info
Power
I did not use the heated seat circuits for the power. Since the passenger seat also had power motor adjustment, I needed to run a power wire for that too. This is a 30A circuit, which is more than enough to do both the power and the seats, so I used it for both.
Heated seat power.
- The correct circuit is under hood Fuse 16(20A). C265, Pin 4, VT-RD in passenger foot well(note I didn't use this)
- I used the passenger seat adjustment power feed for this
- Fuse 31 30A under hood
- 14 Ga White Red wire located in passenger foot panel (C237, Pin 4)
- Cut this wire from connector. Splice and run a 14ga wire direct to passenger seat connector for adjustment power, C300 Pin 1 (big pin)
- Splice same wire with a second 14ga wire and run over to driver seat connector for power heat feed as well, C311 Pin 8 (big pin)
- Driver seat distributes power to passenger seat via relays(located on seat)
- This will Power both the heated seats and the passenger seat motors from the same circuit
- 20ga wire
- Fuse 43(10a) access pass side
- C2280D, Gray Wire
- (Note I didn't use this either). I realized about 6 hours in that I should have run this wire together with the power and ground, and I didn't. Too much work to redo, so I found a switched power wire closer. I noticed in the console a connector that wasn't used....
- Transmission shift selector connector C307, Pin 5, WH-BU wire
- Note I have a manual trans, if you have an auto, this won't work.
- 20ga wire
- Powered by fuse 46 under hood
- It is only 5A but seems to work
- Wire is same 20ga, so could increase to 10A fuse if 5A fuse blows. It is working fine for me.
- Cut WH BU wire out of connector.
- Splice 20 ga wire and run to Driver Seat Connector C311, Pin 7 (small pin)
- Transmission shift selector connector C307, Pin 5, WH-BU wire
- Passenger seat heat power
- Run 16ga wire from Driver Seat C311 Pin 9 to Pass seat C300 Pin 9 - this powers the pass seat heater
- Big Pins(qty 2)
- Signals from HVAC Control module(seat on/off buttons)
- Connector 294A located behind radio bezel
- 20-22 gauge wire(manual says 22 but I bought 20 for the other stuff so I used it). Bigger is fine.
- Run from behind radio C294A to Driver seat connector C311
- Driver Seat - C294A Pin 9 to C311 Pin 5 (small pins)
- Passenger Seat - C294A Pin 10 to C311 Pin 6 (small pins)
- Pass seat ground
- Located under pass seat
- Connector C300, Pin 16. (Big Pin)
- Ground is for both passenger seat heat and power adjustment
- There is a good ground spot up under passenger kick panel. I ran a wire from that to the connector
https://www.allfordmustangs.com/threads/heated-seats-hvac-module-tech-repair-help.285483/
https://themustangsource.com/forums/f803/add-oem-heated-seats-540050/
https://themustangsource.com/forums/f803/adding-oem-heated-seats-2012-gt-premium-542820/
I probably won't check this post much. I had a pdf with the wiring diagrams, but it is too big to upload. I'll try to post diagrams later.
I hope you enjoy the warm buns on a cold day as much as I do!
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