Radio - RPM Dependent Whine
90audi07Subject: Radio Interference From Alternator - Installing Noise Suppression Condenser
Model(s): V8 1990 M.Y.
Group: 27
Number: 90-01
Date: July 31, 1990
Condition:
RPM dependent whine in radio from alternator.
Production change:
Noise suppression condenser installed
As of 10/89 VIN: 44_LN 026 637
Service solution:
Noise suppression condenser, installing
Note
The noise suppression condenser will only eliminate radio noise caused by the alternator. Alternator noise can be identified as a whine that changes pitch in relation to engine speed. The noise suppression condenser will not remedy radio noise caused by other electrical consumers (i.e. fuel pump, ignition system, etc.).
Parts required
Description Part number Quantity
Condenser 441 903 291 1
Mounting 441 903 289 1
bracket
Clamp N 101 029 01 1
Bolt N 014 704 2 1
Nut N 902 867 01 1
Tie-wraps available locally 2
CAUTION
Part numbers are for reference only. Always check with your Parts Department for latest information.
Note
Before disconnecting battery ground strap, obtain radio security code from customer OR disconnect airbag power supply connector and insert computer memory saver tool into cigarette lighter.
^ disconnect battery ground strap
^ remove retaining screws (arrows) and remove sound dampening pan
^ disconnect and remove cooling duct from alternator (arrow)
^ disconnect and remove outer half of air intake elbow from alternator (arrow)
^ this provides access to B + terminal
^ remove edge protector from right front crossmember (if equipped)
^ mount noise suppression condenser to crossmember using mounting bracket, clamp (arrow), bolt and nut
^ route condenser leads through rubber grommet (arrow A) and fasten with tiewraps (arrows B)
^ connect red condenser lead (large eyelet connector) to alternator terminal B+ (upper arrow)
^ connect black condenser lead (small eyelet connector) to ground bolt on alternator (lower arrow)
^ install outer half of air intake elbow onto alternator
^ install alternator cooling air duct
^ install sound dampening pan
^ reconnect battery ground strap
^ reactivate radio using security code (if required)
^ check radio operation
Labor operation:
Diagnosis Repair Quality
check
27 22 31 0 -- 40 TU. 5 TU.