How to Adjust Hands-Free Repeater in Gen 1 OnStar Phone?

[Cadillac Jim]

I have a first-generation OnStar with the Hughes 6100 fixed phone. I use the phone almost exclusively in the hands-free mode. When the phone is active in the hands-free mode, it takes over the stereo audio and that's the phone "earpiece." A microphone on the overhead console is the "mouthpiece." Mine has the dealer-installed additional microphone on the overhead console. When someone on the other end of the call is speaking, the microphone is cut off, and when I am talking the stereo audio is cut off; this is the repeater, and it is necessary to prevent feedback.

Some years ago, at about 35,000 miles, the radio quit, although the hands-free phone wasn't affected. I had the radio replaced on warranty and it worked OK after that. However, when I got the car back the repeater on the microphone didn't work. When I talk, you can hear me on the stereo and the people on the other end complain about an "echo in a barrel" sound. It does OK on receive.

I realize that I should have taken it back to the dealer while the car was still in warranty. I procrastinated and changed coasts, found that analog phones are not accepted for new accounts by most cell phone companies anymore, and decided that my real priority was figuring out how to upgrade the phone to an analog/digital unit. I've since realized that this is impractical and OnStar and Cadillac tell me that they have no plans to support retrofitting phones older than the 2002 model year. So, I must maintain this phone as-is.

The FSM has an entry for adjusting the repeater but, for the procedure, they refer to the service manual for the phone. I don't have that manual and don't see it on Helm, Inc.'s web site. I know a perfectly good dealer that could almost certainly do this but this is the type of job that I would like to do myself. Does anyone have the procedure for adjusting the repeaters for the early dealer-installed car phone hands-free mode? Better yet, can I get a service manual for the phone?

[brmurph]

I have the same problem with my phone on my 98 Concours. Seems like it started the echo about a year or so ago when using the hands free phone. I figured they changed something on the analog network but who knows. You can find the manual on ebay

http://cgi.ebay.com/ebaymotors/1996-97-98-...sspagenameZWDVW

Good luck.

[Cadillac Jim]

Thanks. I'm going to try to get it.

[Cadillac Jim]

I got it. I'll send a check today (July 29) and will get it sometime next week. This weekend I'll see how easy it is to get at the cell phone through the trunk and see what I can while I'm waiting on the manuals. There is some possibility that I may be able to figure out something without the manuals. I'll post any solution to the problem that I find on this thread.