Hi guys, I have a problem that is driving me crazy.
I have a 2002 Ford Explorer Sport, replaced the factory HU with a Sony CDX-MP70. I replaced all 4 speakers with JBL 7525's. I also have an Infinity Basslink that until recently worked perfectly. All of a sudden the subwoofer sounds as if it's blown. I figured the woofer was blown but when I hooked up a buddy's Basslink, (works fine in his setup), I experienced the same issues. Even stranger, if the truck is not running the Basslink sounds awful, If I turn the engine on the Basslink improves but still sounds distorted, like it is blown. I've checked all connections, looked for crimped wires, made sure the ground wire is still secure...nothing has changed.
I did end up connecting a different preamp source to the Basslink and it still sounded terrible. I still don't understand why the sound would improve when the engine is running. It leads me to believe that the problem could be with the ground or power cable since I think I've eliminated the Basslink itself, the RCA's, and the head unit. I don't think it's anything to do with the remote turn-on lead.
I checked the ground connection and the bolt that secured it is unpainted, but the surface itself is painted. I never removed the paint as it seemed to work fine for almost a year. Does a little bit of paint really make a difference? If so, why would this start all of a sudden, and not when I first hooked it all up?
My next step is to replace the power and ground cables. Do you think that's the way to go?

I appreciate any help you guys can offer

 

Scraping the paint should be done regardless of how it sounded. A good clean ground is what you should use as a bad ground can damage the amp. Try cleaning the ground and hooking it back up. How did you run the power wire and is it to the battery? What size wire is it? Sounds as if it has something to do with your wiring. test the voltage of the wiring. The way you have it grounded, it grounded thru the threads of the bolt which can over time corrode a bit and not be enough of a ground.
The effect of sounding a bit better while running the engine is due to 14+ volts vrs 12- volts

 

PrPlayboy, thanks for the quick reply! The Sub's amp is hooked directly to the battery via 10 gauge wire (Infinity recommends 12 gauge) I didn't run it through the firewall. I couldn't find an opening, so I ran it around the side, between the paneling. It's not crimped I thought I might put in 8 gauge instead but I'm not sure if it can have a negative effect.

I'm planning on scraping the paint and making sure I have a clean solid ground connection tonight and see if I can dig up a multimeter. Thanks again!

 

Well, I removed any paint near the bolt and reconnected the ground wire. No change.
I borrowed a multimeter, unfortunately I really don't know much about using them. I did manage to get a reading off of the power wire and it looks like I'm getting around 12v with the engine off. I'm lost.

 

thats not the best way to run a power wire, did u install an inline fuse? also if u upgrade the power wire, upgrade the ground wire. what guage ground are u using?

best ground can be made to the floor pan woth a 3/4" bolt, painted scraped on top with a bolt, 2 washers, lock washer and appropiate nut.

 

I did install an inline fuse (30 amp). I was wrong about the gauge...I'm running 8 gauge power and ground. I bought one of those 200 watt Monster Kits.

I suppose I could improve my ground connection as you suggested, but do you think that will make much of a difference?

 

I have no idea what is wrong with your system but I can assure you this, it isn't the size if your power wire. You could check your battery, most new audio gear will shut down at around 11 volts or start to sound crappy around 11 volts . When you start your vehicle it will be running 14.4-14.6 volts. This could be the reason why it works when your vehicle is running. You need to do a load test on your battery, if the volts don't come back up to 12-12.5 volts after the test your battery is pooched. Most auto stores will do the test for free.

 

hammy is right, the increase in voltage while the truck is running will indeed increase the amps ability to make more power at the higher voltage. the ground wont make a night and day difference but it might help.

 

I want to thank you all for your many suggestions and expert advice. This is such a great site for Ford owners, I'm lucky to have found it. I'm going to hook my setup to a different battery today which I think should tell me if there is a problem with my battery.
It also occured to me that even though a ran my power wires down one side of the vehicle and the sound down the other side that they come together once they meet up in the cargo area. Perhaps ther's a conflict there?

 

crossing paths is usually not a problem. If your having problems with the truck running i doubt it's the battery but it doesn't hurt to have it tested. Being a 2002 i doubt it's an alt problem also. Did you test the romote wire to see if it has a constant 12v? You put your bass link on your buddies set up and it worked fine but did you put another amp/sub set up to your truck? There is a slim chance the voltage on the remote wire is dropping cause the amp to want to shut down and go in a back and forth motion of off and on. is your radio getting hot?

 

My radio isn't getting hot and the remote turn on lead does put out a constant 12v. I didn't put my Basslink on a buddies setup, but I took his brandnew Basslink and hooked it up to mine and it sounded the same. So I know it's not the Basslink itself, the problem lies with my setup. I bought the truck last November brand new so I doubt it's the battery, but I have to explore every avenue.

 

r u sure its not the RCAs? maybe one of the wires inside got crimped or something...just to double check cuz this is puzzling...

 

Yes, it is puzzling. I know it's not the RCA's because I hooked up a boombox with different RCA cables and it sounded exactly the same.

 

How do you know it's not the bass link itself if you didn't put it in your friends set up?

 

Because I took his Basslink, which is working great, hooked it up to my setup and it demonstrated the exact same behavior. Plus, his is brand new. I didn't hook mine up to his setup, becuase I figured that proved that the problem was with my setup, not the Basslink itself.

He put his Basslink back in his vehicle and it works fine again.