First off, I'm not switching from a stock head unit to an aftermarket. There was a broken aftermarket unit in the car when I bought it and I replaced it with a Kenwood KDC-BT848U (or a very similar $220ish kenwood headunit). The radio signal on this headunit is absolutely horrible.

Having searched around, the usual culprit seems to be people are not hooking up the power antenna wire when they install the headunit. To the best of my knowledge, I have hooked this up as it should be (according to the manual that came with the headunit). The wire in question showed 11v on a multimeter when the head unit was on if I remember correctly.

Are there any other issues that would cause horrible radio reception? The poor reception is getting old and I can't figure anything out.

 

are you sure the antenna plug is fully pushed in on the back of the deck? sometimes they need a little extra push to make it click in just right. also check your antenna itself, see if something is exposed or disconnected like a possible plug somewhere. is the antenna an aftermarket one or is it stock? cause that may also be your problem, it could be faulty.

 

There is a separate antenna plug on the back of the head unit other than the main plug with all of the rest of the wiring? Is it the round one with clips on the side?

Yes, the antenna is stock.

 

it wont really look like a wire, its thick and about an inch or longer and silver metal. it looks like this http://www.google.com/products/catal...ed=0CEAQ8gIwAA

see if it is plugged in all the way, sometimes they are a little tricky and make you think it is in. and while you have the deck out, turn the power on and start spinning it around and moving some of the wires, you may be getting interference from a wire that corroded away the plastic or something, you never know, just look at the wires and see if everything looks alright

 

That plug is plugged in all the way. I noticed when I had it out that the plug was spliced into another wire that connects to the main harness. Is that how that plug is normally wired in?

 

no, do you know what it was spliced to? but that may be where your problem is, it could have a bad connection causing your bad reception

 

Ok, I took the radio back out today and had a closer look. The wire isn't actually spliced, I just thought it was when I glanced at it quickly last time. Here's a picture of what it looks like.

Any other suggestions?

 

This might sound a little bit odd, but try unconnecting your ground wire and retesting. I wired in my kenwood recently and didn't need to use the "black ground wire" on my connector.

Is there any chance you have access to another Kenwood deck to test with? See if it's haveing the same problems. If not it's the deck, if so, it's the wiring.