Switch Pops and Motor Noises
Install a blower motor feed through capacitor (part number 3906187). Attach one end to the blower motor and the other end to the hot lead from the blower motor switch. Also, ground the capacitor ground tab (see Figure 1).Figure 1 - For Blower Motor Noise, Connect Capacitor As Shown.:
BLOWER SWITCH POP (HIGH SETTING TO OFF)
Install a diode (diode number IN4001, or the equivalent diode to withstand a 50V inverse peak voltage) from the high speed switch wire (orange) to ground on the high speed blower relay under the hood (see Figure 2).
Figure 2 - For Blower Switch Pop, Connect As Shown:
BRAKE SWITCH POP
1) Install .47 MFD capacitor between wires going to the brake switch at the brake pedal.
2) Install a .47 MFD capacitor from the power lead to ground at the brake switch.
3) Put a 1224205 filter in the dead side of the brake switch with the ground facing away from switch. Try both grounded and ungrounded.
CRUISE CONTROL POP (ELECTRONIC)
Install a new electronic Cruise Control Module. Suppression is built into the new modules.
Figure 3 - Brake Switch And Capacitors:
HORN BLOW-THRU NOISE OR HASH (STATIC IN RADIO SPEAKERS WHEN USING HORN)
Splice blower motor capacitors (part number 3906145) into each lead as indicated. Install the capacitors as close to the horn as possible. Ground the case of the capacitor to chassis ground using metal ground tab on the capacitor. Solder all connections instead of using quick connects (see Figure 4).
Figure 4 - For Horn Noise, Connect Capacitors As Shown:
HORN SWITCH POPS
1) Install a .47 MFD capacitor between the switched power lead and horn lead at the horn relay.
2) If pop persists, install a .47 MFD capacitor from the switched 14 volt lead of the horn relay to ground and a .47 MFD capacitor from the horn lead to ground (see Figure 1).
Figure 1 - For Horn Pops, Connect Capacitors As Shown:
WINDSHIELD WASHER PUMP NOISE
Replace the pump motor with one which has internal suppression.
WINDSHIELD WIPER SWITCH
Ground connecting wiper arm with braided ground strap to dash.
REAR DEFOGGER NOISE OR HASH
A broken grid in the defogger in the rear glass may cause a "hash" in the Radio. Repairing this break will eliminate the noise. A break in the rear defogger grid can be found by touching each "line" of the grid while the rear defogger is on. The cold grid is the one broken.
OTHER ELECTRIC MOTOR NOISES (POWER WINDOWS, BLOWER MOTORS, WINDSHIELD WI PER MOTOR)
Install a .47 MFD capacitor rated at 50 VDC across each motor (see Figure 2).
OTHER SWITCH POPS (BLOWER SWITCHES, POWER LOCKS, PARK-NEUTRAL SWITCH, POWER TRUNK RELEASE, POWER WINDOWS, WIPERS, REAR WINDOW DEFOGGER)
Install a .47 MFD capacitor rated at 50 VDC:
1) Across contacts of the switch
2) From the hot side of the switch to ground or
3) Both (see Figure 2)
Figure 2 - For Other Switch Pops And Motor Noise:
