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Hey guys just started daily driving the C4 for the first time in a decade and at night when I turn my headlights on the interior chime sounds nonstop. Any ideas?
The "Headlights On Reminder" will chime non-stop in PARK or HEAD unless the key is in RUN.
What YEAR "C4"? The chime circuit is not the same for the 84-89 and the 90-96. If the chime stays ON with the key in RUN: If 90-92 check the A/C fuse. If 84-89 check GAGES fuse. (I don't recall what fuse it is for the 93-96.)
(Exactly what IHBD wrote) I get a rapid chime in my 87 of appx 4 chimes per second with key off or key removed and lights on, maybe it is not seeing key on? I get appx 2 chimes per second with key in ignition door open. Schematic is for 88. May be ignition switch or door jamb switch, chime alarm is seeing headlights on but thinks the key is removed. When you leave the key in ignition and open the door does chime sound ?? I think the schematic is a bit iffy here. The schematic shows the two in series when the connector they both run through is C104 but they have seperate pins E & F? I question that.
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I think the schematic is a bit iffy here. The schematic shows the two in series when the connector they both run through is C104 but they have separate pins E & F? I question that.
The schematic is correct. Clarification:
When C1 on the module is grounded, the key in ignition alarm is activated. Connector C104 E & F is the long turn signal switch connector at the base of the steering column. So two switches have to be closed for the module to see ground at its C1: Key switch and door switch.
I looked at a 1988 schematic just now. My recollection was correct, the Key-is-ON input is the GAGES fuse. In the 88, GAGES powers a lot of things, but nothing that the driver would notice not working. Check the GAGES fuse.
Another curiosity regarding the lights-on warning. In my S-10s, the lights-on input to the module is from the gray wire instrument lights circuit. If you want to leave the park lights on with no chime, turn the dimmer full-off. The chime goes off too. In the Corvette, the lights-on input is the brown wire tail light circuit. The 'trick' that works in the S-10 doesn't work in the Corvettes. There are times that I wish it did, I like the feature in the S-10 and use it regularly.
In my testing, the above circuit is for a single chime, the door is open and the key is in the ignition. In that case the schematic is correct. In that case, key off / lights on means that key off must be a different signal path for the headlight chime circuit 39. Which means if all else is correct the audio chime module could be suspect (or the fuse you talked about in the first place).
. In that case, key off / lights on means that key off must be a different signal path for the headlight chime circuit 39.
No. Circuit 39 is HOT with key in RUN. Depending on the state of the driver seat belt, headlights-on, and key switch/door switch input, the key ON or not-ON is used for "logic" within the module to determine which chime is activated.
There is a hierarchy in the 3 alerts, each has a specific 'speed'. (Seat belt, key in ignition, lights on.) There are 5 "inputs" plus the ground. (Seat belt switch, lights-on, key switch + door open, Ignition-on, and battery power.) The "Troubleshooting Hints" and "System Checks" on the left side of the schematic you posted above describe how the system works in pretty clear language, and what to check for the inputs. The OP should follow those. Cheers.
Last edited by IHBD; Sep 6, 2024 at 03:53 PM.
Reason: Added quote and 1st paragraph.
