2000 and up gm radios

Me and another installer were wondering what the deal is with these radios. When i started installing a couple years back, I had an installer teach me that any gm radio with rds needs to have the more expensive harness. However I know this other installer that won't do a 2000 and up gm without using the more expensive harness. It says on the packaging that it maintains a "healthy system status." Now it makes sense to use that. But I have never had a problem with any gm radio. But neither of us have had a clear answere as to why we would need to use the more expensive harnesses. By the way we carry scosche harnesses and the harness I'm talking about is the model number DCGM09.

Is there any way to tell which radio has what going though it.

It's based on year and model...I've heard some installers erroneously say that only radios with "RDS" on them had the data line going to them - but that's def. not the case. It's also not every single 2000 and up GM...as they've redesigned models since then they've added databus radios, generally. Your harness should list which cars it fits...here's a general list. '00-up - Cavalier/Sunfire, Impala/Monte Carlo, Venture/Montana/Silhouette '01-up - Grand Am/Malibu/Alero '02-up - Trailblazer/Envoy '03-up - Full-size trucks Some '98 and up Caddys and the Bonneville/LeSabre/Park Avenue/Aurora/etc. also use databus radios, however they are not the same connector as the cars listed above - I know Metra makes a different model interface for those cars.C Renner's Auto Electronix

My service is cheap, quick, and good - pick any two

If the cavaliers needed it, how come every radio i've installed in cavis without the special harness and just used a normal 18 dollar harness never had any problems with it. Not a one. I think that this is a problem that we need to address because there is so many myths and it will do this and won't do this. I know not to many installers are 100% sure on what is going on in them.

Note carefully - you do not see the word "need" in my post! Yes, you can use Metra's 70-2003 or equivalent instead of the data retention harness or databus interface module...you'll still have to run a switched power wire, because there isn't one in the harness. I haven't heard of that setting any trouble codes - however you still have the issue of not having reminder chimes, and the $40 savings gets eaten up in a hurry when someone leaves their lights on all day and deep-cycles the battery. To summarize - yes you can use a regular harness. It's just not the best way to do an install.C Renner's Auto Electronix

My service is cheap, quick, and good - pick any two

A quick test to see if it's a Class II databus radio is to leave the key in the ignition and open the door. If you hear the door chime through the speaker, it's a Class II system. If you hear it under the dash, then it's anormal radio.Jeff

Velocity Custom Home Theater

Mobile Audio/Video Specialist

Morden, Manitoba CANADA

This sounds very similar to the ARINC 429 standard used in aviation, that I have experience with. Now, I've just installed a radio in a 99/00 blazer and I was wondering if there's a way to allow the signal to continue by hooking up the Rx and Tx wires. The thing i've noticed with this radio is the autoheadlights are not working. This isn't my vehicle it's a friends and they've become accustomed to the auto lights so I need to get them working.

gravityfrog wrote: This sounds very similar to the ARINC 429 standard used in aviation, that I have experience with. Now, I've just installed a radio in a 99/00 blazer and I was wondering if there's a way to allow the signal to continue by hooking up the Rx and Tx wires. The thing i've noticed with this radio is the autoheadlights are not working. This isn't my vehicle it's a friends and they've become accustomed to the auto lights so I need to get them working.

Nevermind, there was apparently an intermittent connection from tne dash getting a little wet last night. And the blazer is a 99 so it's not even subject to the data port radio