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Hey Guru's...
Looking for help/suggestions. My 78 'C3 runs great. the problem I have since I purchased it from the previous owner (he knew of this issue to!), is that the car, while driving, or off, the buzzer will go off. Could take 6 hrs after I drive it, could go off while driving. I installed a Neg. disconnect on the battery so I just disconnect to keep the battery charged. But with that, there goes all Stereo setting. The original theft security system was removed, after market installed, but then removed. Any suggestions? I'm thinking what is tied to the buzzer? Lights, ignition, seat belt's? Sorta want a direction before I start getting behind the dash. Thanks for any info or thoughts..
The buzzer is a black box plugged into the side of fuse box. Its super easy to remove, no tools needed.
It buzzes on my 77 when key is in , door open or headlights on key out.
So when buzzing, I know its pulling amperage, which in turn drains the battery. Do you think they just go to **** and start going off on their own? Thanks for the reply also.
It may be good to start with this. From the 77 troubleshooting manual: The circuit numbers and wire colors may be different on your 78 but the buzzer is the same 77-78.
If you find your circuits read correctly as shown in the circuit operation portion of the page you can always open it up.
If you grind off the 4 corner plastic rivets you can carefully open the buzzer. My original 77 buzzer would not turn off like yours. I found the contacts pitted and actually welded together. A points file cleaned them up. "CAREFULLY" (wire is the size of a thread) open the unit and check the contacts.
Also found a wire that was almost broken so I soldered it.
Last edited by bmotojoe; Mar 10, 2019 at 09:52 AM.
I'm having a similar problem. (Also 1978) Everything functions as designed with the exception of the seat belt function. When I turn the key, the seat belt light no longer lights up at all. It used to work properly when I got the car about a year ago, but now nothing. I've already checked the bulb and it's good. Also, I'm not quite sure the buzzer functions completely as intended for this function. When the key is turned on, the buzzer comes on and after about 8 seconds, it starts to stutter and and fades off. It turns off instantly if I fasten my seat belt as indicated in bmotojoe's post. I know this buzzer box is a bit of late 70's black magic engineering, but if anyone knows how to correct this I'd greatly appreciate it.
I had a similar problem with my 81. Not sure if the buzzer unit is the same, but it was caused by the terminals on the board (riveted on) being a bit loose. Soldering them up so I had good connections again fixed it.
The buzzer's are troublesome as you all have noted. I've taken them apart as well but its the horn that becomes the limiting factor. Those components get old, brittle and circuit patterns get broken. I've searched for replacements at swap meets but with little luck. The horns that make the buzz sound differ as well when you compare a 77 to a 78 and even an 80-81, with the later better made.
I've corresponded with Wilcox about reproducing the buzzers but the limitation is the horn on the board and getting the sound correct. Wilcox has reproduced the tach boards as well as the courtesy light timer switch (orange plastic case).
The buzzer's are troublesome as you all have noted. I've taken them apart as well but its the horn that becomes the limiting factor. Those components get old, brittle and circuit patterns get broken. I've searched for replacements at swap meets but with little luck. The horns that make the buzz sound differ as well when you compare a 77 to a 78 and even an 80-81, with the later better made.
I've corresponded with Wilcox about reproducing the buzzers but the limitation is the horn on the board and getting the sound correct. Wilcox has reproduced the tach boards as well as the courtesy light timer switch (orange plastic case).
To be honest, I wouldn't mind having the buzzer sound different so long as the functionality and connections are the same.
78' buzzer / electrical issue
