Cabral
Active member
- Joined
- Oct 18, 2011
- Messages
- 26
- Location
- San Jose
- Corvette
- 1993 C4 Black Coupe, 2010 White Grand Sport
Another of one of my, "look what I did" posts. Enjoy (or not).
Bought a '93 last year from an acquaintance who had the car under tarps in his brother-in-laws back yard for 6 years. The car was "loaded" with almost all of the options of that year, but it had a myriad of electrical problems. One of the top 5 most annoying problems was the flaky "you left your lights on, you left your key in the ignition" door chime. Sometimes it would chime. Sometimes it wouldn't. Sometimes it would start chiming then stop. Sometimes is sounded like someone was choking a bird! I decided to tackle this annoying problem right away (so that I didn't have to explain the choking bird noise to my friends). Unfortunately my trusty service manual informed me that the door chime module was located deep under the center of the dash, resting on top of the PKE module. In an effort to avoid taking apart the dash, I searched Corvette forums far and wide looking for an easy(er) fix. Damn, no luck! However, I did run into one post where a guy said, "just pound on the dash and the problem will go away". Funny think is, it kinda worked for a little while! Well, the PKE module was the other annoying problem I wanted to get to. So I decided to dig right in and kill two birds with one stone (so to speak). All I can say, is I wish I took pictures.
After popping the dash off (not trivial), the PKE module with the door chime module were easy to find, nestled behind the DIC. To my surprise the door chime module was just velcro'd to the top of the PKE module. Unfortunately, the door chime module and velcro had somehow slid across the top of the PKE module. You could actually see that the velcro adhesive had left a "snail trail" of glue from its previous factory position, to it new position. All I can think is that over the past 19 years, the velcro adhesive routinely melted and solidified, allowing the module to move to its new position. The only thing that really stopped the module from falling of the top of the PKE module was the air duct that it was now wedged under.
The crux of the problem!
Once I disconnected the wires from the door chime module and extracted the module from under the air duct (not trivial), I found that the door chime worked almost perfectly. No choking bird! But why? The "almost" part is what through me off track. If I was to handle the module in any way, even handling the wires, the intermittent chime would return. I thought it was an broken wire or a bad connector or intermittent connection in the connector pair. I tried to isolate the connections, but I just could not get the problem to consistently repeat. I ended up taking the circuit board out of the module and then magically, "Ta Da", the intermittent problem completely went away. Huh?!
The other crux of the problem.
Why would the plastic module enclosure cause this electrical problem? The clue to the issue finally appeared when I put my finger on top of the transducer (the thingy that makes the chiming noise) while it was chiming. The choking bird returned! Then it dawned on me. I picked up the module enclosure and looked inside. There was a small plastic rib molded into the top, right above where the transducer is located. Bingo. I quickly reassembled the chime and was easily able to reproduce the choking bird by just lightly pressing on the top of the enclosure right above the transducer.
That was it! The door chime slid across the top of the PKE module, finally coming to rest pinned under the air duct. The air duct lightly pressed down on the top of the the door chime module causing intermittent pressure, thus causing the it to malfunction. Crap. Can't these problems be easier. I need a beer.
The solution.
Out came the Dremel tool. Two minutes later the plastic rib was gone. After reassembling, the chime works perfectly. I can not make the intermittent chime or the bird sound come back no matter how I touch or squeeze the module. Below, I tried to do my best drawing showing where the rib is located. If you attempt this fix. Be patient, get a service manual and keep track of your screws. You end up with a lot of them in the process of taking of the dash.
In the end it is definitely worth it. And, it beats pounding on the top of the dash.
Bought a '93 last year from an acquaintance who had the car under tarps in his brother-in-laws back yard for 6 years. The car was "loaded" with almost all of the options of that year, but it had a myriad of electrical problems. One of the top 5 most annoying problems was the flaky "you left your lights on, you left your key in the ignition" door chime. Sometimes it would chime. Sometimes it wouldn't. Sometimes it would start chiming then stop. Sometimes is sounded like someone was choking a bird! I decided to tackle this annoying problem right away (so that I didn't have to explain the choking bird noise to my friends). Unfortunately my trusty service manual informed me that the door chime module was located deep under the center of the dash, resting on top of the PKE module. In an effort to avoid taking apart the dash, I searched Corvette forums far and wide looking for an easy(er) fix. Damn, no luck! However, I did run into one post where a guy said, "just pound on the dash and the problem will go away". Funny think is, it kinda worked for a little while! Well, the PKE module was the other annoying problem I wanted to get to. So I decided to dig right in and kill two birds with one stone (so to speak). All I can say, is I wish I took pictures.
After popping the dash off (not trivial), the PKE module with the door chime module were easy to find, nestled behind the DIC. To my surprise the door chime module was just velcro'd to the top of the PKE module. Unfortunately, the door chime module and velcro had somehow slid across the top of the PKE module. You could actually see that the velcro adhesive had left a "snail trail" of glue from its previous factory position, to it new position. All I can think is that over the past 19 years, the velcro adhesive routinely melted and solidified, allowing the module to move to its new position. The only thing that really stopped the module from falling of the top of the PKE module was the air duct that it was now wedged under.
The crux of the problem!
Once I disconnected the wires from the door chime module and extracted the module from under the air duct (not trivial), I found that the door chime worked almost perfectly. No choking bird! But why? The "almost" part is what through me off track. If I was to handle the module in any way, even handling the wires, the intermittent chime would return. I thought it was an broken wire or a bad connector or intermittent connection in the connector pair. I tried to isolate the connections, but I just could not get the problem to consistently repeat. I ended up taking the circuit board out of the module and then magically, "Ta Da", the intermittent problem completely went away. Huh?!
The other crux of the problem.
Why would the plastic module enclosure cause this electrical problem? The clue to the issue finally appeared when I put my finger on top of the transducer (the thingy that makes the chiming noise) while it was chiming. The choking bird returned! Then it dawned on me. I picked up the module enclosure and looked inside. There was a small plastic rib molded into the top, right above where the transducer is located. Bingo. I quickly reassembled the chime and was easily able to reproduce the choking bird by just lightly pressing on the top of the enclosure right above the transducer.
That was it! The door chime slid across the top of the PKE module, finally coming to rest pinned under the air duct. The air duct lightly pressed down on the top of the the door chime module causing intermittent pressure, thus causing the it to malfunction. Crap. Can't these problems be easier. I need a beer.
The solution.
Out came the Dremel tool. Two minutes later the plastic rib was gone. After reassembling, the chime works perfectly. I can not make the intermittent chime or the bird sound come back no matter how I touch or squeeze the module. Below, I tried to do my best drawing showing where the rib is located. If you attempt this fix. Be patient, get a service manual and keep track of your screws. You end up with a lot of them in the process of taking of the dash.
In the end it is definitely worth it. And, it beats pounding on the top of the dash.
