Alright I've just about had it with this subwoofer problem I have a Valor DTS-660WT Multimedia Head unit hooked up with a Cruthcfield wiring harness for the radio and the subwoofer. The head unit works fine, at first the subwoofer was making a thumping sound when I would turn on my truck and when I turned it off I called Crutchfield and they told me to add a regulator (radio shack part # 276-1770) between the blue and white wire of the wiring harness and it would take care of the problem, it did, but the subwoofer doesn't work now, either I have a thump or no subwoofer, well I chose no subwoofer because the thumping sound is more annoying. I really miss having the subwoofer sound, but I can't figure this issue out.

 

E-mail me directly. jjwarren3@hotmail.com

 

Well my subwoofer issue was 90 percent resolved I used the Regulator that Crutchfield told me to use and wired it to the correct wire from the Subwoofer wiring harness and it resolved the thumping issue when I turn on the vehicle, but there still a thumping sound when I switch from the radio to a CD or DVD and when I turn off the truck. Don’t know how to fix that.

 

How did you hook up the step-down? Crutchfield said this was a common problem with newer FoMoCo vehicles. The tech said the Radio Shack part was need to step down the 12v signal to 5 v. Evidently the audiophile setup uses a 5v signal to turn on the sub. I just got mine in the mail (in Germany) and haven't installed it. Crutchfield said for me to call back and they would tell me how to install the step down. Your has three wires on it? How did you hook it up?

 

I soldered the output wire lead from the radio shack part # 276-1770 to the blue/white wire from the subwoofer wiring harness I bought from Crutchfield and the input lead from the radio shack part I soldered to the blue/white wire from the radio. Then I soldered a wire to the ground lead and wired it to the ground wire from the radio. Then I took one of the 6mm Nuts off the sirius radio brain and bolted the radio shack part to it. basically I took the bolt off and put it through the resistor hole and bolted back in place. Just be careful that resistors leads are really fragile and if they flex to much they break off. I messed up three of before I soldered them really thick and added a piece of hard carboard on top and bottom of the solders and made sure that the solders did not flex and break off. Hope this Helps.

 

I have the new JVC KW-AVX800 DVD system.
My speakers make a thumping sound whenever i switch between sources.
The best that i can figure is that when I switch sources, the radio is killing/reducing power to the turn-on lead for a fraction of a second and that is making my AMP power reduce. I did not have this problem before i added the amp. So i figure it has to be the turn-on lead to the amp. I plan on testong this when i have time. Your symptom sounded similar to what i have noticed. Maybe this could help you.

 

Your probably right, I appreciate the help I'll keep monitoring this post for your results. Thanks again.

 

Now, with my "thump", I only replaced the factory H/U with a Pioneer H/U. No amps hooked on my system (at least not yet!). Hopefully I can get to it this weekend, but it's not looking good. It's a "wash and wax" weekend for the KR and SUV. I'll keep an eye out on this as well. Once I install the step-down, I'll post my results.

 

I didn't install an AMP in my truck, but it does the "Thump" thing when I switch sources though. I was under the impression the the stock Audiophile system in my truck had an AMP and a Subwoofer. I'm not to Audio savvy, but I'm learning as I go. I have to research more and find out what the Audiophile system in my truck is composed of. HMMMM