2-12
REDUCING NOISE INTERFERENCE
4.6
Other Electrical Noises
Other elements of the electrical system which can generate noise are listed below. These can be
suppressed by connecting a 0.5 µF bypass capacitor between the noise source and ground.
1.
Ammeter-to-battery lead
2.
Gauges (oil, fuel, temperature)
3.
Ignition Switch
4.
Lamp bulbs (headlamps, tail lamps, dome lamps, etc.)
5.
Accessory wiring (electrical fuel pump, electric windshield wipers, heater fan motor, window
openers, etc.)
4.7
Wheel Static
Road friction can cause static build-up on the front wheels. Suppress noise from this source using
wheel static collector rings (Motorola Part No. 0100534254 regular type - 0100653173 small type).
4.8
Ground Bonding
If a vehicle is not properly bonded to ground, static charges can increase. This increase can cause
noise from electrical arcing. This type of noise is suppressed by bonding the part using one-inch
wide ground straps (keep them as short as possible). Some common points where bonding may be
helpful are listed below (see Figure 2-9 Ground Bonding).
A. From engine block to the firewall.
B. From engine block to vehicle frame at points where the engine is shock-mounted.
C. From the battery ground terminal to the vehicle body.
D. From top of front wheel “A” frames to chassis, particularly in cases where rubber-mounted
members are used.
Figure 2-9 Ground Bonding
Battery
Firewall
Chassis
Fender
Well
Front Wheel
"A" Frame
B
A
C
D
D
FL0830266-O