Need help with Scosche modulator install

First post...been lurking a lot since I got my new (to me) 2007 Cayman S three weeks ago. Thanks to K-Man's good CDR-24 removal instructions, I was able to get my Scosche modulator installed without incident. Unfortunately...it is almost unlistenable. I'm getting lots of hiss and engine (or is it alternator ?) noise. It is almost as if the system is amplifying the rev of the engine. Also, if I hit a bump in the road it registers as a thud on the stereo. It is not even close to the quality of a good fm station (which I could live with). I grounded the unit to the bolt by the fuse box. (Ok, in full disclosure, I did not have the right size wrench and didn't want to buy a full set to figure out the size, so I wrapped the wires around the bolt and secured it. Could this be causing my problems?) I then ran the wires behind the carpet behind the pedals and stationed the unit in the front middle underneath the radio console. I have it set on 87.9. I'm very frustrated. It took me the better part of Saturday to get it installed and is actually worse than the cheap iTrip I was using. Any thoughts on what I'm doing wrong? By the way, the car itself is GREAT!

I installed the same modulator a few months ago and have pretty much stopped using it for the same reasons you mentioned. I have to turn the volume up to about 25 or 30 to even hear the iPod and when I do, the sound is filled with a lot of hiss and engine noise. I have used it about 5 times in about 6 months. At first, I was happy to have the iPod in the car, but over time, and after installing a real iPod adaptor in our Trailblazer I have come to realize that the sound quality of the modulator in the Cayman is awful and not worth the effort. Sorry about not helping to solve your problem. Let me know if you achieve any success in getting better sound out of that thing.

i had the same issue with my FM modulator(different brand). I spent considerable time trying to improve the ground, thinking this is what was causing the issue. I found an area to the right of where the battery installs and cleaned off an area with sandpaper so that i could get contact to pure metal. and installed my ground wire there. There is a black rubber grommet that you can use to pass the wire through your firewall to the driver side cabin area pretty easily. Let me know if you need any pic's and i can take them later this evening. This helped out with the alternator noise but i still have some noise/static. I also installed a noise filter which reduced the alternator whining also. I am really considering paying the bucks and installing a dension....

That's not good to hear. I purchased the Scosche precisely because it seemed to have worked well for many here. Now I'm beginning to think that I should have put that money toward the Dension...

let us know if anything works for you. I hope you can work out the issue with the noise. RR

So, I went to the dealer to get an oil change and to turn the seat belt chime off and I asked about the cost of doing the official Porsche ipod solution. He said they were still waiting on it, so he couldn't quote me a price. Funny, I thought they had been out for a while now. I'm still hoping K-Man S or Suneet will chime in with some inspired wisdom on how I can salvage my Scosche.:helpme:

This definitely sounds like a grounding problem to me. IIRC, the bolt that you grounded to is painted which will not give a good ground. I'd suggest installing a crimp-on ring to the ground wire and get it grounded solidly to metal using sandpaper to remove paint if needed. I've had my Scosche over a year and it works great, no niose, and better signal than the Sirius adapter I was using previously. If re-grounding doesn't solve the problem, then I'd check the antenna connections next. Your signal should sound as good or better than FM radio.

Well, upon Mr. Brown's advice, I regrounded the device. First, I found a wrench that fit the grounding bolt (10mm for those that were wondering). Then I crimped on a spade to the ground wire and connected to the bolt. Sure enough, it improved the sound dramatically. It is still not CD quality, and I get just a hint of alternator noise, but it is much better than the sound was before and also much better than the wireless transmitter route. I think it even improved the volume...I no longer need to crank up the stereo to 40 to get a decent response out of my ipod . So, for those that have been having trouble, I'd suggest revisiting your ground. And thanks Mr. Brown!

I also went back and checked my ground connection. I moved the ground wire to another location and the sound improved dramatically. Again, the sound is not CD quality but it's not awful. Required volume levels are only slightly higher than normal. Thanks for the posted suggestions.

Yea, usually problems like that are ground issues and wrapping a ground around a bolt will never bee good enough. Even if your home stereo starts getting a lot of static at some point, opening it up and torqing the heck out of the grounding screw will probably fix it (and sometimes you really really have to crank down on it). The Scosche is a good system but it's probably the oldest, cheapest system out there so your sound may now be as good as it can get. My iPlug probably cost twice as much but I'm very happy with the sounds. I imagine the Scosche, properly installed sounds pretty good and infinitely better then any wireless solution.

I just installed a Metra FM Modulator and it works ok. I hear a little whine sometimes but only when there is silence or quiet songs with pauses. I just found a different unit on amazon .com I'm going to try it next. Amazon.com: Movies 2 Go FM100A FM Modulator with IST2 Isolation Transformer (Grey): Electronics