I was wondering if the wiring diagram thats on this site for the 1999 Dodge Caravan Sport is for the one w/o the infinity system. Also when I buy a wiring harness will there be a diagram in the package saying what each wire is for?
The radio's wiring harnesses are the same even if you have the infinity system in this particular vehicle. Some of the infinity systems have another wire that's GREEN/ black and this is the amplifier ground--it just goes to any grounding point.
ANYWAYS, once you get the wiring harness (Metra 70-1817 or equivalent), all you'll have to do is match up the colors of the aftermarket radio with the colors of the wiring harness you purchased. This is for everything but the aftermarket unit's black wire, which has to be hooked up to the braided grounding strap of the vehicle.
Only wire you need to be concerned about is the orange wire of the Metra harness. This is a dimmer wire and if your aftermarket head unit does not have an orange or ORANGE / white wire (many of them do not), you'll need to cap or tape off the metra orange wire. Your aftermarket deck may have an illumination wire but I would not hook this up to the vehicle's dimmer wire.
Other than the illumination/dimmer wires, all the other colors are the same with all metra harnesses and most of the aftermarket radio harnesses for units made within the last 4-5 years. But just in case, they will also have each metra wire labeled for its function, so if worst comes to worst, use your aftermarket radio's manual to match up function to function.
Just as a side note, if this car had the infinity system in it, you'd need to hook up your aftermarket head unit's blue/white wire to the blue wire of the factory wiring harness.