Radio/Battery - Auto Muting/Discharges Too Quickly
No.08-51-89
P-669
(C08-64)
Date
February 20, 1989
Index
ELECTRICAL
Subject
Radio System Diagnosis
Models
1988 BB, MJ, XJ & YJ Vehicles
BODY CODE LEGEND
BB - PREMIER
MJ - COMMANCHE
XJ - CHEROKEE, WAGONEER
YJ - WRANGLER
SYMPTOM/CONDITION
Vehicles equipped with Automatic Radio AM/FM Cassette Players may exhibit one or both of the following problems:
1. When the radio is changed to the No. 1 station button from any other preset station, the radio will play for 60 seconds and then mute (go silent) for an instant and resume playing.
2. The battery may discharge when the vehicle is left for long periods without being operated (one to two weeks). The condition may cause excessive current draw if the radio is left ON when the ignition is turned OFF.
RADIO IDENTIFICATION:
DIAGNOSIS
CONDITION 1
Radio mutes when station is changed to No. 1.
Play the radio on any station but No. 1. Change to the No. 1 station and wait for 60 seconds. If the radio mutes for an instant and then resumes normal play, it will have to be removed and sent to an authorized repair station.
CONDITION 2
Battery discharges when the vehicle is not operated for one to two weeks.
If the owner complains that the battery discharges when the vehicle has not been run for one to two weeks, the problem may be caused by excessive ignition off draw through the radio memory circuitry. To determine if the draw is in the radio, turn the ignition on, turn the radio on, turn the ignition off. Disconnect the negative battery cable.
NOTE:
ON PREMIER, IT WILL BE NECESSARY TO CONNECT A TEST LIGHT BETWEEN THE BATTERY POST AND CABLE BEFORE CONNECTING THE AMMETER TO PREVENT DAMAGE TO THE AMMETER. REFER TO TSB 08-51-88 IF YOU ARE NOT FAMILIAR WITH THIS PROCEDURE.
Connect an ammeter equipped with a milliamp scale between the battery post and the cable. Make sure all doors are closed, underhood light is disconnected and there are no other lights or accessories on in the vehicle. Measure the current draw. The maximum current draw allowable for the vehicle with the ignition off is 35 milliamps. If the current draw is more than 35 milliamps, turn the radio off and observe the ammeter. The normal current draw for the radio memory circuit is approximately 5 milliamps. A radio that requires repair will draw between 50 and 60 milliamps. If the reading drops below 35 milliamps the problem is in the radio. If the draw is still above 35 milliamps the problem is in another circuit. Remove fuses, one at a time until the draw drops to determine which circuit the draw is in.
REPAIR PROCEDURE
To repair either condition, the radio will have to be removed from the vehicle and sent to the authorized Automatic Radio repair station in your area. Refer to the AMC, Jeep, Renault Warranty Administration Manual for a list of these repair stations.
When the radio is sent for repair, it is important to clearly state the symptom on the radio repair ticket. Use the following descriptions to identify the defect to the repair station:
CONDITION 1
Radio mutes 60 seconds after the No. 1 station button is pushed.
CONDITION 2
Radio causes battery to discharge if the radio is left on when the ignition is turned off.
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No. 08-60-01-90 (Test and Remove Radio for Repair)
Premier 0.3 Hrs.
Medallion 0.4 Hrs.
SJ, YJ, XJ 0.3 Hrs.
08-60-01-91 (Reinstall Radio After Repair)
Premier 0.2 Hrs.
Medallion 0.3 Hrs.
SJ, YJ, XJ 0.3 Hrs.
FAILURE CODE: 58 - Internal Defect