Hello I’m facing an issue on my 91 mustang 5.0 convertible and I’ve noticed that all of the windows won’t go up or down when the car is running but when the car is in the “on” position all of them work perfectly fine. If any one knows what could go wrong or has any advice it’d be greatly appreciated.
Begin by locating, removing, cleaning, and reinstalling your ground connections:
Battery Terminal
Block to chassis
Battery Negative to Body
Check and post voltages with the car off and key ON --and-- with car running. If you see 15+V with the car running, you have an alt or regulator issue.
Ignition switch is cheap and an easy swap. I'm talking about the switch and not the key tumbler.
Also: The convertible uses a window safety relay that’s sensitive to voltage and grounds. Poor power or ground will kill all windows at once.
Battery Terminal
Block to chassis
Battery Negative to Body
Check and post voltages with the car off and key ON --and-- with car running. If you see 15+V with the car running, you have an alt or regulator issue.
Ignition switch is cheap and an easy swap. I'm talking about the switch and not the key tumbler.
Also: The convertible uses a window safety relay that’s sensitive to voltage and grounds. Poor power or ground will kill all windows at once.
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