99-04 Mustangs use a reluctor-style OSS (Output Shaft Sensor) to tell the vehicle speed. You can test your OSS with a piece of iron or steel (not stainless) and an AC voltmeter.
Connect the pins of your OSS to the AC voltmeter. Rapidly shale the OSS over the metal as fast and as close as you can and you should see 1/3 to 1/2 of a volt on the AC voltmeter:
Connect the pins of your OSS to the AC voltmeter. Rapidly shale the OSS over the metal as fast and as close as you can and you should see 1/3 to 1/2 of a volt on the AC voltmeter:
