Accessory Noise - GMC G Service Manual

9-26 ACCESSORIES

ACCESSORY NOISE

BLOWER MOTOR NOISE (Figure 29)
Install a blower motor feed through capacitor. 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.
Figure 29 — Blower Motor Noise Capacitor
BLOWER SWITCH POP (HIGH SETTING TO OFF)
(Figure 30)
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.
BRAKE SWITCH POP
Install a 0.5 MFD capacitor between the two wires going
to the brake switch at the brake pedal. Also, install a 0.5
MFD capacitor from the 14V lead to ground at the brake
switch.
CLICKING OR POPPING NOISE (DIESEL ENGINE)
1. The problem will sound similar to ignition noise. How­
ever, it won't vary with engine speed. Also the noise
will most likely be noticeable only in the idle condition.
2. The noise is being generated by the high vacuum
switch in the EGR assembly (figure 31).
3. Check the system for any vacuum leaks and repair.
4. If the noise still remains, change the EGR control
assembly.
CRUISE CONTROL POP (TRANSDUCER TYPE) (Fig­
ure 32)
For cruise control engage and disengage pops, install a
0.5 MFD capacitor from the hold line at the transducer to
ground. If disengage pops are still present, splice a 0.5
MFD capacitor across the contacts of the disengage switch
at the brake pedal.