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1988 Town Car Radio Noise

Greetings Bill!

You've helped me in the past. Hopefully you can shed some light on this issue. I've replaced the radio in my '88 Town Car with an aftermarket radio. I've had this problem in the past and fixed it by running a ground directly from the radio to the battery and bypassing the ground supplied from the factory at the harness. But I'm getting ahead of myself here.

When I first got the car, I did a complete tune-up (plugs, wires, cap, rotor, coil) and all of the parts are OE Motorcraft with the exception of the coil. The plugs are OE Motorcraft, standard resistors I imagine.

When I installed the radio, I get the problematic whine that increases with engine speed. I know this is alternator interference. So the steps I've taken to isolate the issue thus far have been: Disconnecting the alternator (whine goes away), replacing the alternator (whine is still there), eliminating the ground at the radio harness and running a new ground directly from the radio to the batter (whine got quieter but still apparent), reconnecting the original ground, keeping the added ground direct to battery, and adding yet another ground from the radio chassis to metal dash (whine still there), and adding a noise filter (did not fix whine). I even tried disconnecting the radio interference capacitor near the coil. NOTHING WORKS!! Of course, putting the original radio back in, there is no whine. There must be some sort of RF interference with either radio, but the new radio is the only one picking it up.

My question is is if you folks ever ran into this and what was done to fix it. It is so terribly annoying and I'd just like it to go away. Something tells me it's ignition related, maybe the plugs, but who knows. Any advice would be greatly appreciated.

Sincerely,

Dan

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Greetings Dan -

Interference noise in radios is a problem that the automotive and radio manufacturers have made great strides in during the last few decades. My knowledge is limited but I will tell you what I have experienced. In the last few decades automotive radios have been built with many static and whine suppressors built into their electronics. Your 1988 Town Car is one of these. Your statement "of course putting the original radio back in, there is no whine" makes me believe that your aftermarket radio cannot do the suppression job that the factory radio can do. For this reason I would advise you to first contact the maker of your after market radio and discuss your experiences. They may have some ideas or even a kit engineered to correct this noise issue.

I also remember repairing a radio whine in an early 70's Ford product that had recently received a rebuilt alternator (twice). The correction was to install a brand new alternator.

Let us know what you find out.

Sincerely,

Bill