Help with headunit!

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Blad09
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Help with headunit!

Post by Blad09 »

I just got a Premier DEH-P930. I wired up the harness and plugged it in and right away blew the fuse. So I double checked all wiring, replaced the fuse and when I plugged it back in got fuzz out of all my speakers and the back side of the deck is getting very hot. This is all happening with all power OFF. Is there something to check for that could be drawing power to create all this heat/distortion? I know it's probably tough to diagnose without having everything in front of u, but I thought it was worth a shot. I just dont get how so much heat is generated with everything off????
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dvnt88
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Re: Help with headunit!

Post by dvnt88 »

Blad09 wrote:I just got a Premier DEH-P930. I wired up the harness and plugged it in and right away blew the fuse. So I double checked all wiring, replaced the fuse and when I plugged it back in got fuzz out of all my speakers and the back side of the deck is getting very hot. This is all happening with all power OFF. Is there something to check for that could be drawing power to create all this heat/distortion? I know it's probably tough to diagnose without having everything in front of u, but I thought it was worth a shot. I just dont get how so much heat is generated with everything off????
Sounds lke you've got a short somewhere that's grounding out, recheck ur harness as well as the remote power to make sure you aren't rubbing metal-to-metal.
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Blad09
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Re: Help with headunit!

Post by Blad09 »

I will check again. Is there any way my meter could be of use to check the deck itself. I have metered the harness and everything seems fine, 12v constant, 12v acc appear to be right. Is this what u mean by remote power? I think its a short inside the unit. I had it opened to look for any sign of damage but all looks fine and I don't wanna go too crazy as I'm not super confident I could fix it if I find whats wrong. Can't I meter the pins where the harness plugs in? If so, what would I check for?? Continuity?? would that help me at all??? So F'N frustrated!
Blad09
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Re: Help with headunit!

Post by Blad09 »

So I got my test light and started checking for any draws. On the Acc line there is a resistor in line that I think comes with the deck harness, anyway with accessories on I have power on the battery side of the resistor but not on the deck side. Could this be my problem?? Do I need these resistors? ( there's also one on the Illumination line) or should I replace them to keep it factory?
Not sure I even know why they r there. :oops:
Blad09
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Re: Help with headunit!

Post by Blad09 »

Got the deck workin. Still gets pretty warm but nothing like it was. Only thing now is no sound from speakers, the odd crackle and thats it. Would this be outputs in the deck? Is it repairable? I really wanna get this thing workin, its got all kinds of features. Maybe I'll try Pioneer for support. Any thoughts on my dilemma are welcome. Thanks.
ttocs
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Re: Help with headunit!

Post by ttocs »

sounds like a bad deck but its hard to tell from here
what else can I say I am a grumpy asshole most of the time.
Blad09
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Re: Help with headunit!

Post by Blad09 »

Bad like throw in the dumpster? Or bad like send it somewhere to get fixed? I know its tough for anyone not here to know whats up but I do appreciate even a guess cuz it may be somethin I didn't think of.
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tonym
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Re: Help with headunit!

Post by tonym »

Can you take it out and test on a bench?
Blad09
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Re: Help with headunit!

Post by Blad09 »

Unfortunately I do not have a power supply so its a real pain tryin to troubleshoot BUT, I may have found the prob. There's a MOSFET that looks like it has arched or something. It is right at the back where its gettin hot. I'm goin out to try n get a pic rite now and that might help. It has about a dozen solders to the board so not sure I could fix it but I'll work on a pic for now.
ttocs
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Re: Help with headunit!

Post by ttocs »

do you have just a small speaker somewhere you can use as a test speaker. I don't even know what car this is going into so if there is a premium sound system in it you might need to hit the remote turn on wire
what else can I say I am a grumpy asshole most of the time.
Blad09
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Re: Help with headunit!

Post by Blad09 »

It's a 98 Ford Exploder, no premium sound. I have been using a Clarion up until today and it was fine. Future shop did the hook up for the guy I bought the vehicle from so its the adapter to the factory harness. The only thing I havent been able to find is a colour code that matches my wiring. Apparently this is a ford thing (changing colour codes all the time) Also, I dont know how to post pics but I did get a decent one.
Blad09
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Re: Help with headunit!

Post by Blad09 »

BTW, my remote wire goes to my amp. I havent hooked it up at all yet cuz I dont like the noise my speakers are already making (running off deck, subs amped only... for now)
ttocs
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Re: Help with headunit!

Post by ttocs »

if you have an extra speaker hook it up and see what you get out of it.
what else can I say I am a grumpy asshole most of the time.
Blad09
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Re: Help with headunit!

Post by Blad09 »

I've had all the speakers hooked up to it already and nothin, just snap, crackle, pop intermittently.
Blad09
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Re: Help with headunit!

Post by Blad09 »

Image
Blad09
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Re: Help with headunit!

Post by Blad09 »

a little fuzzy but u can see where I've pulled the mosfet down to expose the black part at the right of it. That is my suspicion
Blad09
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Re: Help with headunit!

Post by Blad09 »

Well, the deck has been hooked up for about an hour now I can scroll through all the functions, display is good, still no sound out of it and it killed my battery. There has to be a short inside somewhere I just ain't smart enough to figure it out. Gonna take it to a local shop and see if there's anything they can do with it. Thanks for the replies you guys, I really love this forum, I just don't have the proper equipment or knowledge to waste any more of my time and patience on this thing. (even tho I want it to work so bad)
Thanks again,
Brad
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dedlyjedly
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Re: Help with headunit!

Post by dedlyjedly »

You mentioned you had a meter. Is it multi-meter or just a voltage meter?

You tested your power circuits but what about the speaker wires? Most of the aftermarket vehicle wire harnesses and deck harnesses use a standard color code. Do you have grey, white, green, and purple pairs of speaker wires?

If your meter is capable I would recommend testing each of the eight speaker wires for resistance to ground. First unplug the harness from the back of the deck. After setting your meter to test for resistance put one probe on a good chassis ground and the other on one of the speaker wires. Hopefully you get no result on the meter and the display never changes! If the meter displays any resistance that is a sign of a shorted circuit and you know where to start looking.

If all eight speaker wires display no resistance to ground then move on and test each matched pair of wires for resistance. You're looking for a minimum of 3-4 ohms on each pair of speaker wire pair.

If everything looks good after those tests you can pretty much eliminate the wiring as your culprit.
Blad09
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Re: Help with headunit!

Post by Blad09 »

It is a multimeter. I haven't tested any of the speaker wires, but I will when I get home from work today. Also, the first time I checked the power wires both were good, after tinkering with the deck for a while I checked them again and my accesory wire is not getting power anymore. I checked all the fuses and they're all good. I will do another check on all the wires later today and let u know what I find. Thanks for this, I wouldn't have thought to do this myself so thanks again!!!!
Blad09
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Re: Help with headunit!

Post by Blad09 »

And yea, the harness is exactly what u said,
Yellow-constant
Red- acc
Black-grnd
Whites- speaker
Purps-speaker
Greens-speaker
Greys- speaker
Blad09
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Re: Help with headunit!

Post by Blad09 »

Checked all wires again. No shorts anywhere. But still no power on the acc line (with key to acc obviously) I have to assume it is shorting out in the deck somewhere, I just don't know where and as I said before I have no bench to work with so its hard for me to test anything on the deck while its powered up. I think I will take it somewhere and put my shitty ass Clarion back in for now. I would start a WTB ad for a new deck but I am tryin to get the funds to post a WTB Amps ad :D :D :D , so the Clarion will do for now. Thanks for the input guys, this is and will be my first resort to any stereo related Q's I may have, cuz this forum is da shit!!!
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dedlyjedly
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Re: Help with headunit!

Post by dedlyjedly »

Blad09 wrote:Checked all wires again. No shorts anywhere. But still no power on the acc line (with key to acc obviously) I have to assume it is shorting out in the deck somewhere...
You lost me here. When did you lose power to the acc line? Last I checked power was good to go?

Once you have confirmed power, ground and a speaker circuit you've got all the "bench" you need for what you're trying to test.

It's never a bad idea to have a professional do the job if you don't feel comfortable digging in and chasing down the problem though. :thumbs:
Last edited by dedlyjedly on Mon May 23, 2011 8:34 pm, edited 1 time in total.
ttocs
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Re: Help with headunit!

Post by ttocs »

if you had power there and it shorted it would have blown a fuse. Don't bother trying to figure out which one could be connected to the radio and just go in and check EVERY fuse in the block. You can also just jump ther red wire on the deck to the yellow and it should power up.
what else can I say I am a grumpy asshole most of the time.
Blad09
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Re: Help with headunit!

Post by Blad09 »

Lol, I'm lost to!! The first time I hooked the deck up it blew the fuse right away. I replaced the fuse and tried again. This time the deck fired up but got really hot. I unplugged it and checked the power wires (for the 1st time) and they were both good. Tried the deck a couple more times, but it kept getting really hot so I unplugged it. After testing ALL the wires (a 2nd time) including the speaker wires like u said, they were all good EXCEPT the Acc line. Checked every single fuse in the truck and they are all good so that has me baffled. Also, the way u told me to check the speaker wires to see if they were grounding out, I did that on the pins of the deck and the 12v constant is reading 160ish ohms to ground. Is that not a dead short?? But it doesn't blow the fuse, like ttocs suggested, when plugged into the deck???? Thanks for the help guys!!!!
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dedlyjedly
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Re: Help with headunit!

Post by dedlyjedly »

Testing for resistance to ground as I described is a basic test for simple circuits. It's not something I would do, or claim to know exactly what the test means when applied to a electronic device like a deck. Keep in mind that an electronic device has to place some sort of resistance between power and ground in order to utilize any electrical current!

If you believe you've narrowed it down to the deck and you're going to take it out anyhow, I would recommend one more simple test. Disconnect all the deck's speaker wires and properly insulate the ends. Then try to power up the deck one more time. If you're still having troubles with the accessory circuit just hook both of the power wires to the car's constant circuit as ttocs suggested. If the deck still generates excessive heat very quickly with no load attached then it has an internal issue.
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