All dash instruments suddenly died

[rudyhehn]

Hello, On my 2014 Thor Palazzo all of my dash instruments suddenly died. The ammeter, tachometer, speedometer, gas gauge and PSI dials all stay at zero. The warning lights all come on as they should. The fuses are intact. It's like a computer chip froze. Can it be rebooted in some way? Removing the fuse did not work.

[scrubjaysnest]

You may have to remove a lead from the battery to force a computer reboot.

[16ACE27]

Or check for a loose connection. If it was a computer problem the engine would probably be dead as well.

[rudyhehn]

I'll try getting in the dash and unplugging the entire instrument cluster from the power supply. The RV starts and runs normally though the instruments do not show RPM, oil pressure, temperature, etc. Transmission shifter indication is normal as are all warning lights.

[Diemaster]

if you can get the back of the cluster off, see if the black chips get hot. plug it in turn it on and let it sit about a minute.

best way would be to look at it with a thermal camera but not every one has one. carefully feel each black chip. they will be eather cool to burning hot (as in cant put your finger on it more than a second.) if you have a burning chip that could be the reason.

[JamieGeek]

Everything is networked these days; could be a single CAN signal cable loose or disconnected would kill the whole dash.

[avid]

Not an RV, but we had a similar issue in our Tundra. Cruise would kick off at random, cluster lights would go off, and gauges would all drop to zero.

Our mechanic said we had to have a loose or corroded ground connection somewhere. Turns out that the cable on the negative post was very slightly loose, with a little corrosion beneath it. We cleaned both terminals and tightened them. Seems to have done the trick. He said that there could be other ground connections to the frame as well - we just got lucky that ours was in an easily accessible place.

Probably not at all what is wrong with yours, but something else to check if everything else turns into a dead end.

[Cason61]

Originally Posted by avid

Not an RV, but we had a similar issue in our Tundra. Cruise would kick off at random, cluster lights would go off, and gauges would all drop to zero.

Our mechanic said we had to have a loose or corroded ground connection somewhere. Turns out that the cable on the negative post was very slightly loose, with a little corrosion beneath it. We cleaned both terminals and tightened them. Seems to have done the trick. He said that there could be other ground connections to the frame as well - we just got lucky that ours was in an easily accessible place.

Probably not at all what is wrong with yours, but something else to check if everything else turns into a dead end.

Yeah, the Engine has a ground and the frame has a ground. Used to be the engine mounts were the ground to frame but long time ago when I was in my first car, the engine started but there was no dash lights to see the speedo. Got that fixed before my next speeding ticket.

[rudyhehn]

Update- I checked all the connections and did not find anything loose. After recharging and equalizing the house batteries I restarted the coach and magically the gauges all work again. Next time I'll find an old priest and try an exorcism.

[rudyhehn]

After months of losing my dash instruments intermittently, it became permanent. I called the Freightliner rep and he did a valiant job of helping me work through the problem. We tested the dash warning light bar computer console by pushing the computer toggle switch to the right and holding for 5 seconds. This activates a diagnostic menu. It showed none of my instruments were receiving a computer signal from the dash computer. I bought a new warning light bar/dash computer - expensive. Bad news - the instruments worked, but not consistently. The idiot lights all work, the odometer works, but instruments only on and off. Then I had an idea. I disconnected the wiring harness from the output side of the warning light bar/dash computer, removed one of the daisy chain wires that connects one instrument to the next, and reconnected this new wire so that it went from the computer to the tachometer. Viola - it worked the tach. Did the same to the fuel gauge - it worked. It turns out the wiring harness that ran from the computer to the instruments had a short. I replaced the harness and so far so good.