Electrical spook

My son is driving along and suddenly all his instruments go dark and the speedometer drops to zero.
The car continues going along normally.
In a couple minutes, the panel comes back and everything looks normal.
???

Is there a reason why you’re not willing to tell us the year of this Lexus?

Tester

My dodge truck does this all the time. It still runs fine so I continue driving it. If I hit a bump just right it will work sometimes for months then not work for months.

I will plan to resolve the issue when I finally get around to replacing the dash.

1999 i think trying to make this reply 10 characters ha ha

With this smitten of information I can only posit a wild guess that the connection from the Body Control Module (BCM) may have become flakey. A fault code MIGHT be stored if you have a reader that’ll do body codes.

Second wild guess would be a fuse. He can check all that have anything to do with the body/dash circuitry.

If it were mine, I’d check for the possible code, check the fuses, and drive on.

Looking at the wiring diagram, there has to be a bad connection.

The next time the dash goes dark, slap the top of the dash with the palm of your hand.

If the dash lights up, it could be the instrument cluster has a bad board, or the connection to the cluster.

Tester

Do fuses ever fail intermittently? I thought they just blew and that was it.

Fuses are yes/no switches.

Either they work. Or they don’t.

Tester

I’ve had a blown fuse that was intermittent. If the element melts in such a way that the ends can intermittently contact one another, that happens. It isn’t common, but it does happen.

For the record, I’ve also had a fusible link do this too… although it’s unrelated to this post, it does happen.

The first thing to check is the connections to the panel. If they are making a good solid connection then suspect a faulty power connection to the panel. There should be a fuse in the dash fuse panel that supplies power to the instrument panel and a place you could check the power at that point, though the problem could very well be after the fuse position. That fuse would most likely supply power to other things also beside the instrument panel.

The symptoms say faulty charging system to me. I’ve seen that behavior in multiple vehicles that were in the process of suffering a dying alternator. However, they usually continued to die and then would stall. But for a good number of miles the symptoms you describe were in effect. Take my guess with a grain of salt compared to the mechanics on the group. They know more than me about this type of thing.

That isn’t just a guess, it’s the voice of experience. Those who take the voice of experience with a grain of salt are likely to have to learn by suffering themselves rather than from one who has already suffered and learned from it.
Me? I’d rather learn from someone else’s experience than go through the same process myself.

Good post.

A shop could probably set up a volt meter in the car for the driver to monitor as they drive. If the volt meter drops below 12 volts at the same time this symptom occurs, that would be a good clue to have towards a solution.