The following article discuss about the 1993 Jeep ZJ Grand Cherokee Audio
System. This article covers following topics: General Information (audio system description and operation), Power Antenna Relay, Power Radio Antenna, Service Procedures, Standard Radio Antenna and Test Procedures.
Here you can also find detail illustration of charts and diagrams showing the audio system related circuit such as Radio Noise Diagnosis Chart, Radio Diagnosis and Test Procedures Chart, Radio Schematics and Circuits, Speaker Diagnosis, Antenna and Cassette Tape Player Diagnosis, etc. Here is a quotation from the description section:
“All vehicles are equipped with an Ignition-Off Draw (IOD) fuse which is used when the vehicles are originally shipped from the factory. This fuse #F1, which is located in the Power Distribution Center, helps to prevent battery discharge during storage. For specific location refer to Group 8W – Wiring Diagrams. The IOD fuse includes the radio memory circuitry and should be checked if the memory (time or radio station programming) is inoperative. The radio is connected to fuse #8 in order to retain the radio’s memory when the ignition switch is turned to OFF.” (page 1).
Find more information about 1993 Jeep ZJ Grand Cherokee Audio System Service and Troubleshooting here – 12 pages of PDF file docs. (source: scribd.com). Find also other Jeep Wiring Diagram you may interest.