Hello,

I have a 98 LS400 180k with nav, and the stereo has started cutting out intermittently. Some drives it is completely out, and others it works perfectly. Sometimes it works great for a few minutes, then goes out mid-drive, and then comes back a few minutes later. It affects AM/FM, tape, and CD, changing settings doesn’t produce any sound, though touching the nav screen still beeps. It makes me think it’s a loose connection to the speakers.

It seems to be random, not related to going over a bump, turning the wheel, or when under load. There’s no flickering dome lights or alternator/battery warning lights, and I cleaned the battery terminals, radio fuse was also good. No difference.
Sitting in the car parked in key in position 1 or 2 with radio on makes no difference either. Sometimes it works, or if not, I let it stay on and the sound comes back for a few minutes, then starts cutting out again.
electrical issue?

Maybe it’s a bad solder or loose connection somewhere? Dying amp? Where would be good places to look? Is removing the front passenger seat necessary? Any help is appreciated.

 

Do you hear any clicking sound or pop noise when the problem occurs and the sound returns?
Or just the sound is muted without any unwanted noise ?

The reason why I ask you is that to distinguish the root cause. For an example, if your problem is caused by the unwanted mute function, there will be no noise. If not so, the problem may be caused by the connection or the bias voltage related.