2010 ford fusion heated seats

You are testing with the engine running aren't you? That's the only way it will work.

Yea. I'm testing with the engine running. But the ground pulse still doesn't work. Even a manual ground pulse doesn't work. It only works unless I play with the buttons a bit. Then it will work. But, As soon as it's tried after a fresh start it will not. Unless you play with the buttons again then it will only work 20% of the time with a manual neg pulse. That's why I think it's a break neg pulse. When the button is pressed voltage drops from 13.75 to .022 I can count to 2 and the voltage jumps back to 13.75. It does this every time the button is pressed.

If you have a spare 5 terminal Bosch/Tycho cube relay, wire as follows:- Aux to 85. Constant 12V+, fused 2 amps. Switch side to 87a Output side to 30. Good ground to 87. Diode, 1N4004 across 85 and 86, diode band to 86, MANDATORY.

So I would have to actually splice the WHITE/ blue wire. Switch side to 87a and the other side to 30. That should cause a 12v break in that line just as the switch does. Correct?

Yes and terminal 87 supplies the ground at the same time.

I did it exactly as you described it. And still nothing. The other thing that I just found out is if I cut the WHITE/ blue wire with nothing attached to either end, I can press the heater button and it still comes on. Makes me think that the wire is wrong that is detailed to be the right one.

Never mind. The light for the seat turns off after 5 seconds when not hooked up. And when it's attached per your last detail the button doesn't work either. So i'm guessing that its not a break relay setup either. Any other ideas as to what's going on.

So I went through this troubleshooting it. I went back to just a negative pulse. He is what I have done. 1: remote started the vehicle. 2: manually press the heated seat button. Then turned it off. 3: I trigger the relay manually by clicking it on a ground. The seat turns on with the ground pulse. But it only works with a ground pulse if the seat button was previously used. This is really puzzling me and only makes me want to get it to work even more. Lol

I still can't get the heated seats to work. The ground pulse it needs might need a resistor or something on it. But as far as I can see in all the tech logs about this car and the seats it does not. I really don't want to crack open the button control box and solder stuff in there. I am at a total loss. I have read about other people having problems with this car but no one has figured it out, or they just haven't posted anywhere about it.

The main power to the elements should be controlled by a relay probally under the dash. You can activate a additional relay with a latch at the relays to provide fused direct power to the elements. I have only done a 300m with a simular setup, but should be the same.