Head Light Warning Bell

[imported_PunkRacer]

writtin by: A. R. Teitlebaum.
from web site: civic.vtec.net
*note* this is for a 92-95 civic diffrent models my vary**

Install a Headlight Warning Beeper
(Alternate construction using existing beeper)
After leaving the headlights on several times in my "new" '93 Civic EX, I realized how much the car needed a headlight warning beeper. I tried the most common modification, which involves connecting a buzzer and diode between two options terminals of the fusebox, and though my wiring was correct and double-checked, the buzzer I had chosen refused to work. Consequently, I came up with a different modification, using the preexisting beeper within the car's integrated control unit.

Normally, the ICU beeper will activate for several seconds when the car is started with the seatbelt unfastened, or when the ignition key is inserted with the ignition turned off and the driver's door open. I figured the easiest modification would be to trick the ICU into thinking that the key was in whenever the headlights were turned on. To do this, I used a 12VDC reed relay, Radio Shack part 275-233. The relay coil energizes whenever the headlights are on, closing the relay switch and connecting the "key in" line of the ICU to ground.

Connection to the ICU is through the 7-pin ignition switch connector under the dashboard. To access it, you must first remove the driver's side dashboard lower cover (three screws) and knee bolster (two bolts). Two large, black cable bundles from the bottom of the steering column lead to connectors under the dash: a 5-pin connector plugged into the fuse panel, and a 7-pin connector plugged into its own socket.

7-pin ignition switch wiring plug diagram (from wire side):

________---________ KEY and GND are blue/white wires
| ST | KEY | BAT | STart is a black/white wire
+----+-+--+--+-+----+ BATtery is a white wire
| GND| | | | NOTE: diagram shows pins as configured
+----+----+----+----+ in my car; my service manual shows
the GND and ST positions swapped.

Relay wiring diagram (bottom view):

COIL +
(to option
terminal 2)

(
) /
COM ---(--------o o--- N.O.
(to GND) ) (to KEY)
(

COIL -
(to GND)

Mike Timm notes that this modification also works for fourth generation models:

Viewing harness from the rear, GND is on the far right and KEY is in the middle (on the top row of wires). The positive to coil goes into option terminal 2 as does in the later models.

The positive COIL pin (marked with a dot of paint on my relay) is connected to option terminal 2 on the under-dash fuse panel using a spade connector. The COIL - and COM pins are tied together, and wired to the GND pin of the ignition switch connector. The N.O. pin is wired to the KEY pin of the ignition switch connector. I made the connections to the wiring connector by simply jamming the ends of thin, solid copper wire segments into the backs of the pin receptacles. Crude but effective. If the wires between the relay and the wiring connector are short and stiff enough, the relay can simply be left free, supported only by the wires.

With the modification completed, the usual "key in" warning beeper will beep when these conditions are true:

Driver's door open AND
Ignition turned off AND
(Key in ignition switch OR marker lights/headlights turned on)
The relay coil draws a scant 11 mA from the battery while