Around here, no one will warranty electrical parts. They always assume you did something wrong.
Just because the switch has the same number of terminals and looks exactly the same. It might not be the right one.
I found this out last week when a new ignition switch fed power to the kill wire on the magneto, and fried the coil.
I fried a 50 dollar magneto because I installed a truck ignition switch in a tractor and misinterpreted the electrical wiring diagram when it said "ignition module"... Seemed logical to send it 12 volts... Until I saw the smoke rolling out of it...
I had bought a new throttle position sensor for my truck to help with the lag I had between pedal and throttle. When I installed it I heard a "pop" but thought that was a normal sound as i had read instructions online state you should hear a "pop" sound when you shove it on the shaft. I hooked it all up and turned the key... Truck would not start.... Hmmm... Yanked the new sensor off, reinstalled the old one, and the truck started. I took the unwarranted sensor back to the parts store and the owner is a cool guy. I told him what occurred and when asked if I wanted it replaced I said "I rather have the money than a second one from the same place." He understood and he did what he does best, satisfy a regular customer. Of course I told him if he couldn't get his money back not to worry, but he forced the issue with the company as far as I know.
The important thing to understand is that these companies that don't warrant electrical parts know that there are buyers out there that won't challenge them on it, and bank on that. When the receipt says "no return on electrical parts" you take the risk that the answer is going to be no, unless you can either prove them wrong; or buy from a store that the owner knows you personally, and will actually stick up for the customers that he knows aren't stupid, or lying lol.