When I turn the switch on my F150, I hear a click, but then lose all electrical power....lights, horn, everything. Tried jumping to make sure battery was OK, then same thing happens. Without electrical power, I pull on the light switch...nothing. But when I disconnect jumper cables....lights, horn works, until the ignition attempt. Need help. Relay switch?
Sounds like a bad battery cable ground (-) connection. Starting at the battery check all your battery cable connections. They all need to be clean and tight. HTH. -Jim
Battery cables. Do you have replacement leads on it? They need taken apart and cleaned often. Every 87-96 ford with the replacement ends do this. Idk why
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