One alternative is to disconnect the horns, then operate the horn switch. A clicking sound from the vehicle will confirm the presence of a horn relay.
Another alternative is to check a wiring schematic of the vehicle in question.
Brown Negative Siren/Horn Output Wire
Page 19
MOUNTING THE SIREN: Find a location in the engine compartment away from the extreme heat of the engine and manifold. A suitable location will
offer a firm mounting surface, will also allow sound dispersion out of the engine compartment, and not be accessible to a thief. The siren must be pointed
downward to avoid moisture collecting inside it and to enhance sound dispersal. The Brown Siren/Horn output wire has a 1 Amp capacity, which, if
exceeded, can damage the security system control module. Certain situations, among them multiple optional sirens or a vehicle which lacks a horn relay, an
optional SPDT relay is required.
OEM Horn
Wire
OR
Siren
Siren
Black
Wire
Siren Red:
To (+) Terminal
Typical Connections
30
86 87a 85
87
To vehicle's
horn wire.
(+) or (-) as needed
to operate the horn /
sirens
(+) 12 Volts
Brown wire
from module
Configuring A Relay, When Required
Security
System
Control
Module
Brown: (-) Horn Or
Optional Siren Output
Siren (+) Supply Short Red Wire
(Early Production)
Siren (+) Supply -PCB Flag
Terminal (Late Production)
PROGRAMMING THE ELECTRONIC SIREN OPTIONS-
The electronic siren has features which will allow customized options:
1) For louder Confirmation Chirps, cut the Black loop wire on the siren. This loop wire may be wired to a single pole, single throw switch mounted accessible
to the driver, which will allow the softer/louder confirmation chirps as the driver desires.
2) To eliminate the chirps completely, cut and remove resistor R11 on the siren's Printed Circuit Board (PCB). See Programmable Siren Tones below for siren
disassembly and reassembly (R11 is located on the top corner of the PCB).
3) To temporarily eliminate the Confirmation Chirps from the transmitter, press and release the small transmitter button before you press and release the large
arm/disarm button. The Confirmation Chirps will be eliminated for that arm or disarm operation only.
4) Programmable Siren Tones (must have "M3760-3" IC; early production units' tones are non-programmable):
a) Gain access to the top of the siren's Printed Circuit Board (PCB) by removing the two outer, exposed screws inside the siren bell. Pull out the grommet
where the harness enters the bell and remove the magnet/PCB assembly.
b) Access the back of the PCB by removing the single phillips screw in the center (do not lose the Black plastic spacer between the PCB and the magnet).
c) Turn the back of the PCB so that the board number is viewed properly. Directly below the PCB board number are six vertical printed tracks. These tracks
are in order, left to right, starting with the first siren sound heard to the sixth. Cutting a track will eliminate the like-numbered sound.
d) Carefully reassemble the siren in reverse order of disassembly, making sure that the plastic PCB spacer and bell wiring grommet are reinstalled.
