Just installed a new jvc kd-s48 stereo and it cuts out for a half a second every couple seconds. Kind of like a scratched cd but it's with the tuner and mp3. The sound "stumbles" and then it very quickly raises back up. it sort of seems like if I wiggle the wires in the back it'll stop. I will check all connections, I use female and male spade connectors and then shrink wrap over each connection. Any ideas? Could it be a faulty deck?

 

Ok after more driving I found that the volume gets quieter and it stumbles when I accelerate or rev. If I'm sitting at a stop then it's fine. Is this a ground problem? I have constant 12v yellow wire wrapped around a fuse in the fuse box for the time being, I think this could be the problem?

 

This could be any number of things most likely related to the install wiring. the B+ constant sounds like trouble waiting to happen but shouldn't cause this, it's mostly for memory. The switched 12v+ is the real power.

I suggest getting a dedicated Scosche harness for your vehicle & rewire the deck permanantly to it, then just plugging into the existing harness.

Stuff like this happens all the time with diy installs & usually clears up when the wiring is cleaned up.

 

I don't think there is an existing plug in the harness for a radio connection. But if there is then it's been cut out for a loooong time.

 

Oh forgot to mention it's in a 1973 f250

 

Ooooh...they probably hadn't invented constant 12v+ back then ...

Still, start with a multimeter on your power, constant & ground while the radio is running loud & compare to readings at the battery. This load test will tell you where the voltage difference is.

Basically what's happening is the higher voltage when you rev somehow is offset at the deck. 90% chance it's the power/ground, 10% chance the deck is faulty.