I need help with radio interference

I installed a new Kenwood head unit in my 2013 Tacoma crew cab. When i turn the key to ACC all the FM stations come in great perfect reception even HD. But as soon as I move the key to the on position I completely loose my reception as if someone has disconnected the antenna.
Has anyone ever experience this. I Tried putting in the Factory radio to see if it does it and it does but not as severe as the Kenwood. No Led lights no amp nothing extra.

Looking for suggestions any and all help would be greatly appreciated.
P.S. Does anyone know what turns on when the key is in the on position (engine not running)
Thanks

 

Curious what happens when vehicle is running.

 

Same thing as when key is just turned to on.

 

Check all your grounds.

 

x2

 

I checked all the grounds even ran a separate ground directly to frame no change

 

Pull the power wires for every single aftermarket accessory. Alarm, dashcam, light relays, everything.

See if the interference goes away. Reconnect one at a time until interference returns.

If it still doesn't go away, it might be time to start chasing stock circuits.

 

Safe to assume you did not have this issue with the previous head unit?

 

The only after market accessory is the kenwood head unit if i put back in the stock radio it still does it but to a very much lesser degree.

 

If you have any aftermarket accessories that are powered from the ignition side of the electrical system, disconnect all those too.

 

So the new unit is just more sensitive.

You may have some unshielded wire(s) somewhere that are OEM, but failing.

Possibly your alternator (AC signal), or ignition coils are throwing some jizzz at your reception.

 

If you get the noise with key on, but engine not running, try this.

Just for funzies, disconnect your alternator from the loop and see what that does.

Then unpower you coils and see what that does.

 

If you cant figure it out, try one of these

$15 Scosche SLC4 Line Output Converter/OEM Premium Amplifier Adapter - 4CH LOC High/Low RCA Converter Car Audio - Add New Amp or Retain Factory Amp - Line Level Converter for Car Stereo - Quality Sound

https://www.amazon.com/dp/B000BFL52Q

 

Keeping the head unit hooked up pull it forward out of the dash and see if the noise still persists. If it goes away you can use Mu-metal around the radio to shield it from the radiated EMI noise. Very old school trick we used to use when install radios in early 80s Ford trucks. The main dash wiring harness ran right over the radio location and would cause havoc with the magnetic head pickup for cassette tape players and both AM And FM reception.

 

It still does it when i pull it out.

 

Disconnect the antenna and hook up a cheap separate one and see if it goes away. You may have a cut shield on the antenna line. If it goes away by doing this you'll have to look into replacing the antenna.

 

Old truck of mine had some cheap LEDs on the back for work lights. If you turned them on radio reception completely disappeared. Not sure if that’s a possibility for you or not.

 

I tried 3 different antennas and I have no led lights on vehicle still the same problem.

 

Does anyone know what actually comes on with the key in the on position besides the so called (Idiot Lights).

 

Fuel pump relay.
Other relays I am sure.