Difference between Alpine & Mopar Cd Changer

I have just fitted an alpine head unit to my 99 XJ and the factory changer would not work, it just whirred and clicked.
After some serious investigation and internet searching it is clear that no one actually knows the difference between alpine CHM-xxx changers and mopar cd changers so here goes.
The cd changer from Mopar as fitted to my 99 XJ which seems pretty standard has the Data Bus pin 1 and Data Bus ground pin3 reversed. Swapping these pins over immediately brought it back to life.
None of the other signals are swapped, the lead between the head unit and the cd player is a one for one, there are no crossovers etc.

So if you want to use an alpine head unit with the mopar changer or a mopar head unit with an alpine CHM-xxx changer you will have to swap pins 1 & 3 either in the lead or the changer, depending on how confident you are.

This does not apply to Alpine changers that use the Ai-net interface, it only applies to M-bus changers.

Hope this helps because it would have helped me!!
Pete

There is no standards for that every Audio Manufacturer does it their way.

Just out of curiosity, how did you figure this out? When it didn't work, you just started randomly switching wires around?

Heck, I'd have said screw it and gotten a CD changer from the same manufacturer as the head unit.

I'm an electronics engineer, it wasn't that hard & no I didn't swap leads around until it worked that would have broken something.
To be honest all the information is out there on the net, just not all in the same place, 4 hours of research and I had the answer.
I originally did say screw it but what bugged me is that the cd unit is from the same manufacture it's just that jeep want you to pay twice as much for the same thing.

Yeah, I believe he is correct on the wire swap. I had a 2000 Dodge Stratus and wanted to put a changer in. I found out that Alpine actually makes the OEM changers for Chrysler. They change the wiring a little so that most people will go through the dealer for the changer or head units. They want like $600 for a changer? There is a company that makes an adapter specifically for this application and I bought mine at circuit city. Worked great and allowed me to use the stock head unit to control the Alpine changer which in my opinion, are the best. I think the adapter was about $25 or $30. I am an aircraft electrician for the US Army and did consider doing the wiring swap myself because I have alot of experience in this area but feared I'd burn my new changer up, so I just bought the adapter. Piece of mind was worth it!

A little off topic, but I've read the new ALPINE Head Units are the only ones that can control the iPOD satisfactory?

True, the other brands can connect & control the iPOD, but the reviews I read said the interface was horrible and it was so slow and with so little visible info, that it was worthless.