If the yellow and black wire is just a small diameter I do not think it is the power supply for your seat. The power feed wire for your seat should be a larger wire and most likely will have the power and ground in a two prong connector.
Put tester on it and it lit up thats why i believe it goes to something under seat
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tryed a tester on it and tester so i believe it do connect to something under seat
Put tester on it and it lit up thats why i believe it goes to something under seat