I don't think buying the amplifier is risky...

I talked with Peter at GDL online. He was very nice and suggested: If you get an amplifier rebuilt- install it and drive 50-60 mph down the road. Activate the unit.. if it doesn't work right. Turn it off and don't do it again and again. He said a bad actuator will fry an amplifier. I've got a system apart right now and am battling a similar thing.

I know on my car the amplifier was bad.. low mileage and both had been replace by 60,000 miles.
Maybe I've got a bad speed sensor or switch.

Michael

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Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E