I just bought a 2004 3500 quad cab. The previous owner had a pioneer deck, 4 boston acustics speakers, 2 fosgate amps, and subs under the rear seat, but took most of it out before selling it. When I got it, it just had the pioneer deck, and the 2 speakers in the rear doors.

I just put a new fosgate 4 channel amp under the driver's seat and 2 new speakers in the front doors. I hooked it all up, ,and its got problems. The front speakers only have base running through them (no high range, tweeters doing nothing), and the rears don't have any base at all (is that normal for the back speakers in these trucks?)

I hooked up some different speakers in place of the front speakers, and they had the same problem, so I know I wired the speakers/cross overs right. So that narrows the problem down to either the amp, the RCA cables or the deck, right?

I'm thinking the RCA outputs in the head unit might be bad? That would explain why the last guy didn't take the cd player before selling the truck...

Any ideas?
Thanks for putting up with the long post.

 

Have you tried switching the the RCA output on the back of the deck? You said the rear are putting out highs so put the rear output RCA to the front input on the amp and see if that then causes the fronts to have only highs.

 

Let me know how you wired into the front speakers. I long shot might be something to do with the factory wiring to the speakers.

 

check the wires for blockers. they are small and round and look like a AA battery tapped into the wire. If they are there take them out they are blocking all the high end and only letting the low pass. I used to work for a stereo shop back in college and we put alot of those in for a cheap way to get bass.

 

I'll try switching the RCA's when I get off work tomorrow.

The front speakers are wired into the stock wiring where it goes through the hinge of the doors, and it's stock from there to somewhere in the middle of the dash area I think. I haven't looked at where it was tied in on that end, but that's where the speaker wires coming from the amp head to.

I'll trace the rest of the wiring and look for the blockers.

 

There's some info in a previous thread stating that the rear speakers are not full range...they don't produce low frequencies. All the bass comes from the front speakers.

 

1) some decks will have 3 different output channels also. front-mid-rear(bass). when you turn the bass up it will go to the rear channel more so than others if it is that kind of head unit.

2) does your amp have a bypass on it?

3) if it is just hooked up to the speaker wire outputs and not the RCA outputs, is there a high range blocker on the speaker wires?

 

Double check your amp to make sure you don’t have the Xover turned on to high pass/low pass.

 

If it is wired through the factory systems and you had the infinity system before than that would most likely be your problem. The infinity system comes with an internal amp that distributes different ranges. Just see what happens when you switch the wires. Also, do make sure your amp is turned to the correct fequencies like others were saying.

 

Also, on many Pioneer head units there is a function called "FIE" which refers to "forward imaging enhancement", which sends bass only to one pair of speakers and mid/treble only to the other pair. Make sure FIE is turned off in the head unit.

 

I switched the RCA cables front to rear, and now the front speakers work fine and the rears don't work at all.

The crossovers are all set to let everything through, and the truck did not have the infinity sound system. Since the front speakers work fine now, that rules out any kind of blocking in the speaker wires. FIE is off.

So now it looks like that one pair of RCA cables is only transmitting low range, and since the rear speakers don't play low range, they just don't do anything right now.

 

Is the rca outputs on the deck front and rear outputs? Also, did you switch the jacks on the deck or on the amp? Knowing this will help narrow down to the amp or deck. Hope we can determine the problem.

 

Most pioneer units have front/rear/and sub preouts. If you have your rca's in the sub preouts you will only get sub freqs to those speakers. Usually the front and rear preouts hang about 6in out from the back of the radio and the sub rca's will plug right into the back. Also check the sub control in the radio to see if its on/off.

 

I switched the jacks on the amp. I've never had the head unit out, so I haven't seen how the RCA's are connected to it. It would make sense that they're connected wrong. The sub control in the radio is on.

Is there an easy way to pull the deck out if you don't have the quick release keys for it? Probably a stupid question, but I've just never done it before.

 

go to best buy and purchase a set of keys. all pioneers should work on each other as long as it is the same din size.