Subaru Legacy 2002 Service Manual page 2899

Communication System
B: INSPECTION
1. HORN RELAY
S904436A1001
Measure horn relay resistance between terminals
(indicated in table below) while connecting terminal
No. 4 to battery positive terminal and terminal No.
3 to battery ground terminal.
Current Terminal No.
Flow
1 and 2
No flow
HORN SYSTEM
S904436A10
BO0308
Standard
Less than 1 Ω
More than 1 MΩ
COM-4