DuoMaxwell

My car is a 2004 Dodge Stratus R/T Coupe, and I'm working on getting a carpc into it. I took the dash off and there's a HUGE factory head unit (4cd changer) in it. Anyway, I have an old portable screen that has RCA/S-Video inputs.

I tore the screen out and luckily there are two daughterboards so everything...including the inputs...are spread out pretty well so I have the screen fitting and all the circuitry in easily-accessible places. This LCD screen runs off of 12V DC so I shouldn't have any issue hooking it up straight to the battery.

Now then, I had a bit of an issue with sound. I was a cheapskate and decided I'd just try an FM Transmitter but that didn't work too well. So...I decided to just get rid of the head unit and buy an amp that I'd hook into the computer. I had ordered it but then I found out that I have a premium infinity sound system in my car....which already has a stock amp underneath the passenger seat so I simply bought a wiring harness and now I'm golden with sound (4RCA's). An added perk of the wiring harness is...I get 12V wires...one is already switched by the ignition and one is a constant 12V, so I'm pretty much set on powering the LCD.

So then, now I have my audio and video hooked up correctly...all I need is something to go to the screen itself. I have a spare motherboard but nothing else for it, so currently it runs off of my laptop with centrafuse and a Navibe GM720 gps. I plan to get a USB FM Tuner and hook it up to my external antenna. I also plan to buy a cheapo 7" wide touchscreen (The current screen is a 5.5" regular screen and fits perfectly with no cutting into the dash).

Finally, I just got two 12" Alpine Type-R's for free...so I'm currently working on sound hookups for that, but basically here's what I'm still waiting on.

-4GA Wire and RCA's
-Equalizer (to split my sound between the subwoofer amp and interior amp)
-Subwoofer amp

I already have a capacitor and the rest.

Overall, I don't think this build was that hard. Before I opened up my dash I previously had absolutely no knowledge of carpcs etc...I just did the best I could with what I knew. Everything fit together pretty nicely by luck so I guess I'd say I'm pretty lucky. I'll have pics up soon, currently I'm on my laptop away from the car.

-Duo Maxwell

brucedog

Hey Max,

That was a nice little tale of the trials and tribulations that most of us have gone through to find out / figure out what we've got and what we need to get the carpc up and running.

I haven't heard one, but that stock sound system should do ya fine, if the volume level you desire can be achieved. You could always split your audio outputs of whatever carpc to feed stock audio amp and add-on sub amp - just takes an RCA Y-type connector and maybe a coupla cables... My sub amp has adjustments for low pass, etc on it; I'll bet most do, so you may not need equalizer.

I installed internal pci Creative sound card with 5.1 sound outputs, so all amps, sub can be easily fed. The sound card has decent little eq, plus other sound-enhancing features. Sounds pretty nice.

You will need some sort of lcd screen as that old one only has s-vid, etc inputs and won't provide adequate res, connected to mobo.

Best of luck and blessings.

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Happy CarPC'ing!

DuoMaxwell

Well I was working on the car yesterday, I hooked the wiring harness up and something weird happened. WIth the key out of the ignition nothing had power....no power door locks etc...with the key in the ignition set to on everything worked fine. I was freaking out thinking my body control module was cooked.....but then I went under the hood and found out (after many hours of beign worried) that it was just a blown 10A fuse. One thing does suck....when I was closing my hood I put a dent in it. I pushed it back out from the other side but its still slightly misshapen...and I'm OCD about those kinds of things.

One problem, whenever I tried hooking up my laptop to the Metra harness I got no sound which is rather weird. I'll poke around tomorrow and see if there's another blown fuse....but is there any way the head unit communicates with the amp in some sort of way other than sending sound? Or maybe the wiring harness I purchased is no good?

Oh, and about the screen...I'll pick up a cheapo touchscreen off of ebay (~150 for a 7") with VGA inputs because the RCA's don't provide much resolution. The stock sound system sounds amazing for being stock so I'm not worried about that. I just can't wait to get those two TypeR's working and shaking my car.

Thanks,
-Duo Maxwell

Grrrmachine

That bit worries me. The screen might be 12V, but your battery is 12.6V and with the engine running, it's 14.4V. If you do that to the screen you've just bought on eBay, your $150 will not last long.

Also, if you're running the amp and the laptop off the same wiring, it'll mean the same fuse. Laptops aren't power hungry, but that and the amp would be enough to pop a 10A fuse if they both turned on at the same time. The PC really should have its own dedicated power line and fuse for safety reasons, and just share the ignition-on cable as that has no significant current draw on it.

Your non-sound problems could be some sort of remote-on signal between your non-existant head unit and the amp - a simple test is to touch the audio jack ends when you think it's on, to see if you get a buzz from the speakers. If you dont, you may have to replace the amp too or find a more complicated solution. That's proprietory gear that you'll have to search the forums for your answer.

FusionFanatic

are you planning to use that laptop as your permanent carPC or will you be replacing it with something else down the road? what are you using to power the laptop?


if you're going to power the screen off the car battery, then make sure the screen has some sort of power regulation to deal with the fluctuating car voltage. if the screen came with a cig lighter plug with an in-line regulator then make sure you use it. if it's just a plain wire then open up the cig lighter plug to make sure there are no electronics inside it before you hardwire it in.


how did you blow the fuse? did you short-circuit the wires, or did you overload the circuit? hopefully you're not trying to directly power anything extra off of those stock amp wires.


well something has to tell the amp to turn on/off. the switched 12v wire may come from the head unit, and now that you've removed it the switched 12v wire may not be powered anymore. if this is the case then you'll have to connect it up to an ACC line so it turns on/off automatically.

did the wire harness come pre-wired or did you hook it up? do you know the pin-out for the harness/connector? are you sure the stock amp accepts low-level inputs? sometimes stock amps have speaker-level inputs, if this is the case then your laptop's audio-output will not be a powerful enough input for your stock amp.

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current carPC setup
previous carPC setup

DuoMaxwell

Ok so here's my progress for today.

1) I went down and measured the 12V Ignition that used to power the head unit to see how much it fluctuaes....and it stays below 13V so I wired the LCD (the RCA inputs one) + to that 12V wire...and then just took the negative and grounded it and wala....it works.

2) I found out which wire (they are color coded and it tells you on the harness bag which wire is which) is the amp turn-on wire and wired that up to the 12V ignition as well. I ran RCA's from my laptop to the harness and wala...it worked. Only problem is it is rather quiet so this was kind of a huge waste of time.

3) To try and get a little louder volume, I plugged the sound into the LCD screen's audio inputs...and then turned the volume all the way up and then I connected the headphone jack coming off of the LCD screen to the RCA's on the harness. This is extremely ghetto and I'm probably just going to bypass the stock amp but for now its what I decided to do. The problems with this are that the screen's amp is kind of crappy....when there is nothing playing you can hear a little bit of background noise and if nothing is playing a high-pitch tone stays on (very faint) which gets higher as the engine revs higher, obviously because of the battery voltage increasing. I don't mind this too much because 1) it sounds like a turbo =P 2) all i have to do is unplug my input source and it works fine.

Well, currently I'm trying to decide what to do. I will be getting a Boss GT1080 which is a two channel amplifier with 300RMS watts on each channel. It cost me about 90 dollars shipped and I'm trying to decide whether I should keep it or Return-To-Sender it and order this US Amps (Better Quality) amplifier that runs 400RMS watts on each channel, which is closer to the Alpine's 500RMS limit. The only other two things I have to decide are whether I want to buy a touchscreen off of ebay (150) and whether I want to keep the interior sound how it is now or if I want to just buy an aftermarket 200 watt amp for the car.

Oh, and to answer Fusion's question...I don't think I'll be keeping the laptop running the CarPC but it was powered by its battery + a charger connected to a 140 watt inverter. I think I'm just going to throw my old 1.8GHz Pentium 4 (512MB of RAM) into it or just build something new for it. To power it I'm going to buy a 300 watt inverter because they aren't too bad on price (around $40 shipped). I have centrafuse but I can't find US Maps for it and I don't feel like paying another 100 for destinator but I'll figure the software end out later.

Any suggestions appreciated....and sorry for my novel long posts =P.

-Duo Maxwell