Hey guys, first post.
So anyways, I am soon going to "inherit' my dad's 1996 Jeep Grand Cherokee and would like to carputerize it. I have an extensive background in computers, so i'm not worried about the computer part, but i am a noob when it comes to car electronics, so i have a few questions.
Ok so my first project will be to replace all the speakers in the Jeep, because the original ones are cardboard replicas of speakers. (at least that's what they sound like )
Is every correctly-sized speaker out there going to work with my Jeep? I'm kind of confused about the stock setup i have. Is the amp built into the casette/radio player? If i replace it with a new cd player, will I also need to get a new amp? What are the advantages of having an amp?
Next, power questions-
What i was thinking is, why the hell do people buy opus power supplies for like $150 when all you need is one of those cigarette jack-to-120V outlet things? Then i thought, well that would mean that the computer would turn off whenever the car did. BUT THEN i thought, why not hook up the two wires in the 12v jack directly to the battery? Isn't that essentialyl the same as an opus?
Next, wiring questions.
Is there enough room in the paneling to accomodate for a few new vga, usb, ps2 wires? Also, are there any length limitations or will the quality just decrease as the length increases?
Thanks alot for all your help.
Ok first your question of the speakers. Pretty much you want to find the nicest set that will physically fit. The wattage of the speaker is important as well because it lets you know how much power you can apply to them.
Unless you have a premium sound package you amp is built into the headunit. If you replace it you will prolly get a headunit with amplified output. When looking at them you should see a number like 50W x 4. This means it applies 50 watts to each speaker. The advantage you an amp is that you have more power and cleaner signal. Unless you are looking to disturb an entire neiborhood the head unit will prolly be good enough. I suggest you get one that has Auxillary input so you have hook your computer up that way.
Now to the power. The reason people use opus is that it is more efficient. Going from 12V dc to 120 AC then back to 12V dc is not efficient and there are more losses. If you hook it up straight to the battery, you could possible drain your battery dead if you left it hooked up while your car is off. The opus has protection against that because when it starts to sense a low voltage it shuts itself off.
You should have no problem fitting cables. Keep them as short as you can. Any more questions???
Ok I think I am following your logic....
You wish to have a second battery so that way if you computer drains it till its dead, your car still starts correct?
Can this be done? Yes, but its not as simple as hooking up one battery straight to the other. If you hooked one up to the other, the carputer would drain both batteries till they were dead. What you want to do is electrically isolate one battery from the other. However, you need it to charge when the car is on, so you don't want it to be isolated while the car is on.
To do this you will need a relay, and it needs to be capable of carrying high current. Something like this
I will post a circuit diagram.
You're really belittling the OPUS here. It also includes startup/shutdown timers, which will cost you $50-$100 more to add to an inverter. If you *ever* have a question that starts with "well why the hell dont people just ... ?" then that means you need to search more. MP3Car people have thought of just about everything, and have tried pretty much every possible way to hook up their carputers.
hmm.. no amp... :-)
stupid cheapo parents :-)