!996 XJ12 stereo not working

I have the Harmon system with the CD changer in my car and also the factory Motorola phone. My head unit sometimes does not turn on and other times it does but all the controls are frozen. I pulled out the phone and the phone “box” from the trunk but still these symptoms continue. I have swapped out the head unit with another and still have the same problem. Does anyone have any suggestions? I do have another Harmon amp on the way to try.

Many thanks
1974 E type OTS
1984 XJS
1996 XJ12

TSBs from when I worked at the dealer.

15-03 Radio Selectable Features.pdf (26.3 KB)
15-26 In Car Entertainment – Radio Inoperative.pdf (27.5 KB)
15-29 Automatic Volume Control.pdf (15.2 KB)
15-31 Incorrect Speaker Mapping.pdf (18.7 KB)
15-32 Poor AM Reception.pdf (11.7 KB)
15-41 Radio & CD Autochanger Compatibility.pdf (80.6 KB)
15-43 Poor Sound Quality.pdf (85.2 KB)

1 Like

I would start with the supply. Check the fuses are clean and tight.