If this is an original radio, unfortunately you're falling victim to what we call "GM's customer-unfriendly business practices", meaning they do things that benefit GM at the expense of their customers.
In this case, all through the 1990s, they had a 100 percent failure rate of the laser assemblies in their CD players. Years ago there used to be one model of boombox, by Panasonic, as I recall, that used the same assembly. If you could find one of those, you could transplant that assembly. Other than that, the only way to get the part from GM was to buy the entire CD player mechanism, however, one of those business practices was GM was the first manufacturer to stop allowing us to buy their radio service manuals after 1994. Ford did that after 1997. Up until then, Ford had the best service manuals, and GM's were very nice too.
Without access to service manuals, you can't get part numbers. Without part numbers, you can't order replacement parts. Those radio parts do not come through or get ordered from the dealer's parts departments. There used to be three authorized repair centers you could order parts from, but they don't take the time to look up part numbers for us little guys.
I visited one of those authorized service centers in 1999 when I was buying hundreds of Chrysler radio manuals. They treated me like royalty, and helped me find a 2"-high stack of manuals to drag home, but in the conversation, I found out they were just in the middle of losing their authorization to repair GM radios, partly because they were only shipping out two UPS trailer loads of radios per day, and GM considered that small potatoes; too small to bother with. Today you're tied to two grossly-over-priced repair centers. As late as 15 years ago you could expect a bill of close to $450.00 to have the dealer remove, send n, and reinstall an AM / FM / cassette player. CD players were about the same cost. Instead, most owners went to places like Best Buy to get a perfectly fine aftermarket radio for much less than half the cost of repairing the original one.
To combat that, starting with a few 2002 truck models, GM started building the Body Computer into their radios so they could not be switched out with an aftermarket radio. To try to do so would leave you with no audible turn signal click and multiple missing features that were run by those Body Computers. Most of what they dream up is designed to force you to go back to the dealer for repairs.
The next problem is due to the age of your radio, the authorized service centers likely will not work on it. For a long time they've been telling us they don't have parts for older models.
Another problem is when there were still parts available, they never diagnose down to the individual defective part(s) like we used to do with tvs and vcrs. Instead, they simply drop in an assembly. No alignment, no adjustments, and no modifications are necessary. Repairs that way take just a few minutes. The first problem is that's like buying a new car because the tires wore out on your old one. You're forced to buy more than you need. That has been another GM practice since the mid '70s with their generators and HEI distributors. It took the aftermarket industry to step up and make repair parts available.
The other problem with these assemblies is, as I mentioned, they truly did have a 100 percent failure rate of the laser assemblies. All of their replacement player mechanisms came off the assembly line at the same time, so the replacements are no different than what is in your radio now. With the 100 percent failure rate, the replacement, if you can find one, is going to fail eventually in the same way.
There is one ray of hope. Most of GM's full-size trucks used a three-piece radio with the receiver under the dash, the control head in the middle of the dash, and a remote cassette or CD player mounted separately below the control head. If you have that same setup in your truck, look for the CD player in a salvage yard. I don't know if those had the same high failure rate. They did use a different laser assembly, so those might have held up better. Also, if it didn't get used much, failures take longer to occur.
Now that I shared all the bad news, there's a few other things to consider before chucking the radio in the garbage. First look at the CD you're trying to play. If it's a store-bought disc, it will play. If it's a disc you burned on a computer, those will not play in some players. Computer disc recorders burn the "table of contents", (TOC), in a slightly different area on the disc. On some players, the laser sled is physically unable to move far enough to read that table of contents. When it can't read it, it doesn't know where to start, and it won't know where to look for any track. You'll get an "ERR" message for that.
Next, if no disc works, there can be road dust collected on the laser "eye". You can try a cleaning disc first. The better ones come with a small bottle of cleaning solution to drop onto the brushes. My experience has been those can work when the dust is rather fresh and wipes off easily. Don't expect it to clean a laser that's been sitting in the elements in a salvage yard. For that, you have to pop the cover off, then, if you can see the laser, clean it with glass cleaner on a cotton swab. Be very gentle. The eye will push down and sideways very easily. Don't use Brake Parts Cleaner or Carburetor Cleaner. Those will melt the plastic lens.
For another type of failure, you may find some discs play normally while others don't, or the unit will work fine with all discs at times, then stop working with all of them. Or, if it plays for a while, then cuts out, the laser could be getting weak. It's rare to run into that because they usually fail completely long before they get weak. The better suspect then is a light film of dust needs to be cleaned off the laser.
Another failure involves it starting to work intermittently after hitting some pot holes or bumps in the road. The laser sleds used to run on a pair of chrome-plated metal rods with a very light grease on them. Dust collects in that grease, or it becomes hardened over time. A potential clue is it might start working in warmer weather. Cleaning those rails is needed, then a light film of "Phono Lube" will keep the sled from sticking. When the sled sticks, the laser eye will start to bend or tip at an angle in an attempt to follow the track, but it can only bend so far. Once it is no longer able to follow the track, the sound will either cut out completely or it can skip and play the same section over and over. Either way, when that happens, it will try to reset the laser to the center of the disc when you insert a new one. That might break the sled free and let it start playing that disc. The sled can take up to 70 minutes to cross the disc, which is about 1 1/2" wide, so it moves extremely slowly. That's where it's easy to get stuck. When you eject a disc, the sled runs back to the starting position in a matter of a few seconds, so it's unlikely to become stuck at that time.
To add to the misery, a lot of manufacturers went away from those chromed rails to save money. Instead, the sled runs on grooves in pieces of plastic. They can work fine when they're new, but over time anything plastic is going to wear. These are the ones where we see sleds getting stuck. Sometimes, once enough pressure builds up from the motor trying to move that sled, it can snap free and continue on. Usually there's no noticeable symptom, as in the sound cutting out momentarily, or a noise coming from the player. Dust buildup will aggravate this as well as the grease going away or becoming hardened. The problem has to get worse and worse over time before symptoms show up. We clean and relube those rails when we're doing any other service to them.
If your radio is a one-piece unit, you can try some of the things I mentioned, but consider this an opportunity to buy a nice aftermarket radio that you like. I repair only original equipment radios. I never got into aftermarket stuff because there's just too many models and too much to learn. A $70.00 dollar service manual might only get used once in my lifetime, and that's almost twice what I used to charge for repairs. As such, I don't have any recommendations as to what's good or bad.
If you're "emotionally involved" with your radio, or if you want to keep the truck original, start by looking on eBay for replacement mechanisms. It usually takes a dozen tiny screws, and two or three electrical connectors, and you're done. Also do a search for independent shops that still repair your model. There used to be a place in Minneapolis. I tried to find the place a long time ago, but I got hopelessly lost on their miserable streets. I could see the business across a field, but I couldn't figure out how to get there. By the time I wound my way out of the residential neighborhood, the shop was closed. Years later, as in roughly ten years ago, one of their employees was selling replacement CD mechanisms on eBay. He is the person who told me those were GM original mechanisms, and they would have the same failure rate. Most of the time they lasted long enough for the vehicles to make it to the salvage yard at the end of their lives.
Being a '97 model, I don't have any diagrams or instructions I can post for you. If necessary, I can offer hints or suggestions based on my experience with older GM models. Let me know how you'd like to proceed and how I can help.
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Sunday, December 17th, 2023 AT 4:32 PM
