Problem with Aftermarket Headunit Installation

[joshy0077]

Hey folks,

I don't know how many people are familiar with these types of installs, but I could really use some help because I'm quite perplexed by the situation.

Here's the deal, I tried installing a JVC AR5500 headunit into my 02 liberty today. I purchased an aftermarket (scosche) harness so that installation would be a breeze, or so I thought. I got all the wires connected that JVC had on their wiring diagram, except the aftermarket harness had 3 wires left that weren't connected to anything...those being a FUSE B(+) wire, a PCI BUS wire, and another GROUND wire...all of which are also found on the factory harness. Assuming there were no real problems I plugged in the unit, turned it on...and it worked great! However, the liberty had the words NO BUS on the odometer, and the check engine light, battery, and oil lights were lit up, as well as none of the gauges worked. I plugged the factory unit back in and everything was back to normal except the check engine light stayed on....what am I doing wrong or not doing in order to get this all to work?

I included pictures of what the wires look like as well as a checklist of the wires that are connected (red = connected).

You must be registered for see images

You must be registered for see images

 

[BoeserBlick]

The PCI wire is (presumably) the bluewire (with the white stripe). Typically, on most aftermarket HU's the blue/white wire is the system remote. The system remote is used to turn on external amps when the HU is turned on. Not sure what function it served with your stock HU.

The yellow wire is a power wire - evident of the fuse. I would have thought ths would be your 'constant' power wire, but it looks like you got that taken care of already.
I also dont know why you have an extra ground.

I'm guessing that the harness you have was meant to be used with a stock HU - not an aftermarket one. The extra power & ground wires tell me that the stock HU probably has a function that is powered seperately. Something like the motor for the CD player or cassette in a stock HU.

I would suggest you try getting a harness made for aftermarket HU's. For most installs I've done, I've usually had wires left over on the HU side... not the harness side.

Not sure what to tel you about the the various dash lights, etc. If theres one thing I've learned, auto manufacturers all wire their vehicles in ways only the original engineer would understand. Chryslers notoriously cryptic.... My Jeep itself has all wierdo (non-industry standard) colors.

 

[joshy0077]

Well the harness I have is also a scoshe harness (http://www.cardomain.com/item/SCOCR02B), and seems to be made for aftermarket units. According the the factory wiring diagram there are two PCI wires, one is blue with wite stripe, and one is brown. I have the brown one connected to what is supposedly a cell phone kit on the headunit (that I don't intend to use). There are two yellow wires, one of which is connected the other is not, and then the extra ground. Would the extra ground be causing the problem, should I ground this wire to a screw somewhere, or try switching them? Would connecting the extra power wire to the ground "complete the circuit" per se? Any additional help is greatly appreciated!