Wierd symptoms, your input please

thanks in advance guys....having weird symptoms on my friend's minivan radio (96 Dodge Caravan) it's a pioneer deh7400 (i believe) anywho.....for some reason she's able to control the volume when the actual radio's on.....but when she switches it to cd mode she can't control the volume, once in cd mode .....if she puts the volume on zero then you'll hear a lil pop and no music.........anybody ever heard of this?  

-------------
*paw print*

Are you using external amps?  Did you use the power antenna wire as the remote-on for the amps?

-------------
Support the12volt.com

thank you so much for your response....i'm not aware of an external amp to be honest....but i did notice (when i checked the wires) the remote wire WAS hooked up to the antenna wire.....i disconnected that and seemed to have made no difference.....i noticed no ground wire but the radio still functioned regardless....... i decided to add one and ground it (no factory ground wire option) by finding some type of metal fixing....but that seem to have made no difference... 

-------------
*paw print*

Adding a ground is a good idea (many newer verhicles ground the radio through the mounting location, which is poor at best.)  I suggest you connect it to the vehicle chassis, not to just any metal lurking under the dash as that may not be any better grounding point than what you already have.  

(Some Pioneer heads do not offer both a power antenna AND a remote-on wire.  They only use one wire (blue/white) that functions as a remote-on.  If your head only has one blue/white wire, then ignore the rest of this.)  The remote antenna wire (usually blue with white stripe) should be connected only to the power antenna. This wire gets 12V only when the radio is playing, and is off when the CD is playing.  The remote-on for the amps should be a solid blue wire.  This is on anytime the head unit is on and should be used to switch on any amps.  It sounds to me like you are using an external amplifier that is not switching on with the CD but is on with the radio.

If the above is not the case, then if the CD will not play your head is probably defective and needs repair/replacement.

-------------
Support the12volt.com

again friend....i appreciate the response, and also to all those who viewed this.....i did the liberty of grounding the ground to some type of metal fixing because i wanted to keep the ground wire as short as possible....but at the same if i DO ground the wire to metal chassis....is it ok if i use longer wire as my ground? I know for the "best" ground they suggest using the least amount of ground as possible (keep it as short as possible) so i guess i'll just RE connect the antenna wire then,lol....oops...lol.....so bottomline is i guess....we're dealing with an external amp.....or the deck is bogus now?.....it worked before which is weird.....i guess i'm going to have to do some research on this hidden factory external amp....

-------------
*paw print*

Glad to be of some assistance.  Running a long ground wire for a head unit is OK as the power draw is very small.  Short ground leads for large power amps, yes.  If you are using no external amplifier, then the HU is probably toast.  Sorry!

-------------
Support the12volt.com

DYohn] wrote:

---

lad to be of some assistance.  Running a long ground wire for a head unit is OK as the power draw is very small.  Short ground leads for large power amps, yes.  If you are using no external amplifier, then the HU is probably toast.  Sorry!

---

an update on what just happened....she just told me that her deck just stopped working all together....so i told her to bring it back to my house so i can take a look at it...i'm going to look for that external amp (where should i look? under the seats?) but i'm also going to hook that antenna wire back up (with the blue/white wire) and also find a better ground.....also Dyohn another question for you if you will?.....on the yellow wire (12 volt constant) there's usually a lil box prior to the actuall harness....would that have anything to do with it? cause this one does not come with the radio anymore

-------------
*paw print*

The blue with white stripe is the amp turn on wire and the solid blue wire usually is the antenna lead. on the dodges and chryslers for that matter, almost half of them have an external infinity amp running the speakers. all you need to do is simply connect the AMP turn on wire to the factory amp turn on wire...and it will work. chances are the pioneer deck only has one wire, the blue/white which is an amp turn on wire. sounds like the radio is bad. got any others to test in the van just to make sure?

OK. here we go. Lets make life easy for you. That deck will only have a blue/white wire and no blue wire so thats your amp turn on wire or remote wire. You were right to ground the deck but in  a chrysler vehicle there is very often a large flat strap that looks like braided wire behind the deck, thats your ground. Hook up the blue/white wire off the deck to the blue wire off the adapter harness on the vehicle side. See if you get sound. If you do then switch to cd and see if the sound is still there. If it is then just finish the connectons (ie solder, butt connect, whatever) and put the vehicle back together. If you still get no sound then its very likley that the CD section of the head unit is toast and needs to see a doctor. I dont believe there is a blue/white amp turn on lead on the chrysler harnesses but I cant remeber for sure because I am having a total memory laps right now. If there is you can try to hook it up to the blue white off the back of the pioneer deck and see if you get sound. Being that you got sound on radio and not on cd, compounded by the fact that that pioneer deck definatly does not have a power antenna lead, leads me to believe that the deck has an internal problem, but let us know what you find. And BTW the little black box you speak of is generally a line filter and are almost never included on newer decks anymore.

-------------
double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

Ravendarat wrote:

---

OK. here we go. Lets make life easy for you. That deck will only have a blue/white wire and no blue wire so thats your amp turn on wire or remote wire. You were right to ground the deck but in  a chrysler vehicle there is very often a large flat strap that looks like braided wire behind the deck, thats your ground. Hook up the blue/white wire off the deck to the blue wire off the adapter harness on the vehicle side. See if you get sound. If you do then switch to cd and see if the sound is still there. If it is then just finish the connectons (ie solder, butt connect, whatever) and put the vehicle back together. If you still get no sound then its very likley that the CD section of the head unit is toast and needs to see a doctor. I dont believe there is a blue/white amp turn on lead on the chrysler harnesses but I cant remeber for sure because I am having a total memory laps right now. If there is you can try to hook it up to the blue white off the back of the pioneer deck and see if you get sound. Being that you got sound on radio and not on cd, compounded by the fact that that pioneer deck definatly does not have a power antenna lead, leads me to believe that the deck has an internal problem, but let us know what you find. And BTW the little black box you speak of is generally a line filter and are almost never included on newer decks anymore.

---

first off i want to thank everybody once again....this is tremedous help....Ravendarat!!! you're the man....a question if you will....that braided flat ground wire i failed to mention....i took that out btw and replaced it with an 18 gauge ground wire.....big mistake? If so...is it possible if i can substitute for another type or gauge wire? i'll keep you guys posted....thanks so much for hanging in there with me...

-------------
*paw print*

It doesnt really matter as long as the deck is grounded properly. Personally I would probally use a 16 gauge wire but 18 is probally fine. That grounding strap isnt really Ideal for a ground but its convenient so almost everyone uses it.

-------------
double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

Ravendarat wrote:

---

It doesnt really matter as long as the deck is grounded properly. Personally I would probally use a 16 gauge wire but 18 is probally fine. That grounding strap isnt really Ideal for a ground but its convenient so almost everyone uses it.

---

hmmmm interesting that you mention that.....cause everything was prety much wired the same when i took a quick look behind the deck, except for that braided ground wire.....i just took it out (threw it away) and used the 18 gauge wire to replace it cause it looked neater......it's just hard to understand cause i've used the same set up in my prior installs.....and the deck worked fine before i did this.....i should've just left it alone....*pouts* if it ain't broke then don't fix it saying is starting to apply to this application all of a sudden for me...sheesh

-------------
*paw print*

another question if you will....i remember disconnecting a (random) wire that somebody "jerry wrigged"  by twisting them together and used as the 12 volt constant....i'm thinking that particular wire had something to do with the "external amp" ......if so....(this particular wire is not connected any longer) should i try reconnecting this to what wire in the back of the deck? i also tested this wire and it seems as though as it's hot only when ignition is turned...(pos 2)   

-------------
*paw print*

after you figure out the whole remote turn on/power antenna thing, check this out.  some chryslers have two ground wires going to the factory head unit.  one is the braided ground wire, and another is a black wire that would have plugged into the back of the factory head unit.  that black wire  i am pretty sure is the amp ground for some of their infinity systems.  have your head unit and that wire grounded to make sure the amp works properly.  i worked on a 92 caravan and the amp didnt work properly until i connected that thin black wire to ground as well.  im not sure it will, but i hope this helps.

audifive wrote:

---

after you figure out the whole remote turn on/power antenna thing, check this out.  some chryslers have two ground wires going to the factory head unit.  one is the braided ground wire, and another is a black wire that would have plugged into the back of the factory head unit.  that black wire  i am pretty sure is the amp ground for some of their infinity systems.  have your head unit and that wire grounded to make sure the amp works properly.  i worked on a 92 caravan and the amp didnt work properly until i connected that thin black wire to ground as well.  im not sure it will, but i hope this helps.

---

*pouts* still nothing....this is what i've done..

- deck works (hooked it up to my own vehicle)

- re-attached antenna wire (blue) with remote wire (blue/white)

- re-ground (clean metal surface) to another area

i'm stumped guys....but thanks to you guys at least i have a clue at least......dodge using 2 grounds aye?.......hmmmmm i honestly only replaced the flat braided wire (ground) for a 18 gauge wire and grounded it in it's same place.....i'm guessing that "second" ground is daggling somewhere behind or something.....i need to find that external amp, or "second" ground...this is killing me guys!! *pulling fur out*

-------------
*paw print*

Bypass all the factory wiring and hook it up like it never had a radio to start with.  I have seen to many factory wiring problems cause this. You never know if the factory wires could be bad, Someone else rewired it, etc.