Aftermarket Radio Grounding Locations

[BigSlappy]

First thing I want to say is thanks everyone for the amazing help on these foxbodies. My dad has always had a foxbody when I was growing up, so i always grew used to them. Everyone has been super helpful with info and resources.

One of the last issues I really have with this car is the aftermarket radio I installed. When the car is started, you get that alternator whine. I assumed the default ground the default radio has isnt that good, so I just grounded it to the latch nut for the glove compartment. The whine is a lot quieter, but is still there. For anyone who has installed aftermarket radios, how did u guys wire up the power and ground? I have new speakers and amp all connected to each other, so I no its not any old hardware.

 

[AeroCoupe]

Remove the ground and see what happens. Used to get a ground loop due to the antenna. If that fixed it we left it with the head unit utilizing the antenna for the ground as we were not going to chase the grounding issue with the customer’s car.

That being said if that fixes it check your grounds in the car starting with the battery to body, body to engine block, and the firewall to cylinder head ground strap. If those check out then my guess would be it’s a dash harness ground issue.

 

[Noobz347]

And refrain from adding more than what AeroCoupe listed until you resolve the issue at the very least. [Extra] grounds are what causes a loop and those can induce noise to the head unit.

 

[TIGGER]

One more thing to add is do not rule out the radio and or amp. I had an annoying whine in my wife's 96 vert a few years back. I chased the grounds. Switched the RCA cable etc.... It ended up being the amplifier that was bad. One of the channels was bad and was picking up the alternator. I figured it out by unplugging one of the channels from the amplifer and the noise went away. Other channel sounded just fine. I replaced the amp and have had no whining issues since.

 

[limp]

Back in the day, it was the spark plug wires that created all of the noise in our 4 track and 8 track tape decks........
Corvettes needed the stock metal dist cover in addition to as I assume the fiberglass body didn't help....

 

[BigSlappy]

Remove the ground and see what happens. Used to get a ground loop due to the antenna. If that fixed it we left it with the head unit utilizing the antenna for the ground as we were not going to chase the grounding issue with the customer’s car.

That being said if that fixes it check your grounds in the car starting with the battery to body, body to engine block, and the firewall to cylinder head ground strap. If those check out then my guess would be it’s a dash harness ground issue.

I have my antenna off, so maybe putting it back on will fix it . Ill do that and adjust my brake booster today and update everyone

 

[BigSlappy]

One more thing to add is do not rule out the radio and or amp. I had an annoying whine in my wife's 96 vert a few years back. I chased the grounds. Switched the RCA cable etc.... It ended up being the amplifier that was bad. One of the channels was bad and was picking up the alternator. I figured it out by unplugging one of the channels from the amplifer and the noise went away. Other channel sounded just fine. I replaced the amp and have had no whining issues since.

I have a couple amps lying around i can switch out. I really hope its not an amp because thats the only 4 channel one i have

 

[AeroCoupe]

I missed the amp part. What brand of amplifier is it and where do you have it mounted?