Thats great if you an amp installed

 

Add a ferite core

 

You can use them without an aftermarket amp. 97 XD has an aftermarket JVC headunit in it with Polk Audio speakers & zero noise thru the speakers. When I fixed the dash I found a pair of those. They were kinda taking up room, removed em temporarily & oh man did it sound awful without them (engine noise/alternator noise) Slapped back in & super quiet. You can get a pair on ebay for 12.00.

 

Your new stereo has probably insufficient 12V DC filtering. The stock stereo has a big toroid choke to filter out noise coming from the ignition and the 3 phase AC alternator which gets on the 12V supply. You can see that by measuring with an oscilloscope.

These stereos are made in China nowadays, not like the solid stock one which was made in Japan. The choke inductance is 1mH followed by a 4700uF block capacitor to ground (pls see picture). You could try a DC filter like these:

https://www.ebay.com/itm/1Pc-POWER-1...O/282424322977
https://www.ebay.com/itm/1-NOISE-FIL...0/273061305002

 

I never would of thought it would matter not having an aftermarket amp in place. I do have a wad of RCA connectors so I'll give it a shot.
Thanks.....

 

No problem! I’m actually gonna order me a set for my 02 as it’s aftermarket unit also whines a bit. After hearing the difference on the 97 XD.

 

I picked one up last night. Do I plug into the input or output? And the grounds just go to chassis ground somewhere?

I’ll post up my results once I get it in there.

 

Red/white on the filter go to the stereo RCA’s. The speaker side plugs into the other side using RCA leads connected to your speakers.

 

Attworth, did you see my thread and get that boss audio headunit that plugs right in? If so, I ended up getting the harness that makes use of the RCA outs and my static went away. I didn't realize I had an amp...