New member here -- been reading a long time but never needed help. I have a C6 (2005) Convertible (manual top) with about 27000 original miles on it. Yesterday, I drove it. Popped the roof release and stowed the convertible top. (The windows go down automatically when you unlatch the roof). Now, they will not go up -- neither window from either the driver (or the passenger) control. I can't find a wiring diagram to help figure out what is preventing it. I checked the fuse (30A in cabin box passenger side) which is ok. That fuse also runs the fuel door release and that works ok. I replaced the battery last week and thought the auto indexing feature got squirrely so I went through the procedure of holding the button down for 10 seconds and then trying it and trying to hold the button up for ten seconds. No good. I disconnected the battery and waited a few minutes and reconnected it -- still nothing. I put the top up and down a couple times thinking that maybe a switch in the tonneau cover or the roof latch assembly wasn't being made (or not made) but still no luck. Also seem that the power mirrors are also affected -- they don't work on either side. Also, not sure if it is related but it is suspicious, the anti-theft light on the dashboard is lit when the car is running. Without a wiring diagram or someone who is familiar with this problem, I am shooting in the dark. Any help or suggestions is appreciated.

 

Moving this to C6 Tech for some advice to your problem.

 

Welcome to the forum. I don't have a convertible, so I have not looked into how the system works. I do have the service manual section with the schematics on the convertible top, so I'm adding it here. Hopefully, it will help you troubleshoot the issue with the windows. I'm sure someone with a vert has had this happen since 2005, so you will get some help.
Good Luck

 

Make sure the divider in the cargo area is snapped in place good. There is a microswitch behind the snap on the passenger side. If this switch is not pushed in the windows will not go back up. This is a safety switch to make sure there is enough room in the trunk when the top is folded down.

 

Thanks you for sharing. I just ordered a service manual as well. This car, though still "new" by mileage standards has been a real electrical nightmare on a number of occasions. I appreciate your help!

 

Thank you. Even with the wiring schematic, GM doesn't make it easy to troubleshoot with one module having to talk to another module. It's the user information like you're putting forward that is really helpful. Thanks.

 

Do you have both doors closed when you attempt this ?

 

yes. i've tried with them open, with them both closed with one open and the other closed.

 

I've also tried with the engine running, with the engine off and in accessory mode both with doors open and doors closed and with the top up and the top down (I have a manual top so no motor function is affected).

 

Welcome to the forum. Have you had this car since new or is it recently new to you? Would like to know the age & condition of the battery? If the condition is unknown, invest in a new battery. If the battery you have is known to be good and has not been drained & recharged, then disconnect your battery and wait 10-15 minutes. Be sure to put your top up and locked. Then reconnect and attempt to index your windows following the below procedure and see if this process helps. Also be sure to check that your battery cables are in good shape as well and can be securely fasten to your battery terminals. You may just need to give your electronics a good reboot.

The service manual states that if the anti-theft light stays on, then you need to have the car serviced.

Let us know your results & good luck.

GD

 

He can't get the windows to go up at all. It is not an indexing issue.

 

Ok. So I tried all the obvious things including checking every fuse in the engine bay and in the passenger foot space -- all good. Checking body grounds where I could. I tried disconnecting the battery overnight and reconnecting it. Nothing. I was gonna pull the door panels to hotwire the windows up and I decided instead to take it to a local shop I have used and trust. I spoke to the owner (in the business for 40 years) and he though it was a serial bus issue but I paid him to check it and that's what he told me. He could order the windows up with a laptop connected but he said there are all kinds of serial buss error issues and that he recommended taking it to a Chevy Dealer for the repair. I shudder at the cost for putting my windows up and down. The car has 27500 original miles on it!

 

If your shop says it’s a serial data bus communication issue take the car to an auto electric shop…it doesn’t have to be a dealer and most are clueless when it comes to diagnostics..I see you are near Tampa…Austin and Sons looks like a good auto electric shop !!..if you want to try to find 2 splice packs near the steering wheel you can try to remove the “bus bar” or “comb” as we call them on each splice pack.

 

Thanks for the heads up (my heads-up display, by the way, does not work either). I will call Austin and Sons for an appt.

 

Like I had mentioned if you can find SP205 by the parking brake assembly and are somewhat mechanically inclined and just know how to use a voltmeter remove that comb and see if the windows and HUD come back online you can save yourself some money…the HUD and Driver Door Module are on that splice pack.

 

First of all...... THANK YOU for taking the time to help me diagnose the problem. I am usually the one who is guiding people to help solve their problems. The Denali video is priceless! I am a firm believer in being as knowledgeable of my vehicles (and other stuff) as I can be even if I can't find the problem but at least your response has provided me with a road map to success if I am skilled enough and persevere long enough to discover it and fix it. I am now considering investing in some more sophisticated tools to help. Thanks you again for your kind consideration.

 

No problem !!…CAN communication issues really require a labscope, breakout box, and a “higher” level scan tool and is a little more complicated as far as diagnostics go…I looked at another wiring schematic which shows SP205 on the left side of the IP if you want to try to locate it.

 

Ok. So thank you all for your input and suggestions, especially that link to the Denali video on the serial buss which really provided an education to me on how my car (2005 Corvette) works. So following your advice, I decided to try my hand at fixing my problem. Using your diagram, I disassembled the parts in the way in the driver's foot well and found the splice pack referred to. I pulled the "comb" and tried all the things that had not been working hoping that by removing the comb, communication might be restored to the serial buss. It was not to be. A few other things were no longer working like the gage cluster which made perfect sense and I had probably cut power to it when the comb was removed. I feebly tried to check power of pins to ground in the splice pack but northing made sense and the love/hate relationship with this car kicked in and I threw up my hands and surrendered. Someone had recommended Austin and Sons Auto Electronics in Tampa. I called them to make an appointment and they told me that they specialize in trucks and they are a Ford shop. There are very few auto electronics shops around. There was one in Clearwater that closed because they couldn't complete with offshore cheap replacements (posted on their continuing website) where their business was rebuilds. I called a Corvette specialty shop near me -- they had also closed after 25 years. On a recommendation from a friend, I took the car to Belleair Auto Care. They found the master window switch was putting out a false reference signal to the serial buss that was keeping the modules from talking to each other. When he called me tell me they had located the problem, he also told me that :"bad news" that my harmonic balancer was coming apart and that the "fix" on this car is expensive because to get to it requires removal of the steering rack to get to it -- it makes it an all day job. I told them to go ahead and take care of that too after watching the operation on a YouTube video and deciding that was also a little more than I wanted to do. I now have my car back and things are working again the way they're supposed to.

Thanks to all those who contributed and those who simply read my post thinking "poor bastard. I'm glad it's not me but I don't know what to tell him. (LOL)".