Dash gauges malfunction

Follow the wires going from the speedo. What do they connect to? Whatever it is they connect to try to find a ground source connected to it. May be a simple loose or corroded ground wire.

Big Blue: I don't think there is a website for Freightliner service bulletins. The only one (SB) I've found is the one about the System III dash instruments.

The Freightliner Help Desk will make pertinent SB's available if it relates to a problem you're having. That's probably how the SB 54-12 got on the internet. The help desk has always been very helpful for me.

Fred

fcooper wrote:
Added via edit: Forgot to mention Welcome to the Forum. You can get a lot of help here.

Suggestion: add a signature line giving us some specifics about your coach. This can eliminate a lot of confusion.

According to the newmar brochure for your motorhome, you could have a ford, workhorse, spartan, or freightliner chassis. All of these will have different systems for the dash instruments.

If you have a ford, workhorse, or spartan chassis, the below info will not help you.

If you have a freightliner chassis, the link below is the troubleshooting guide for your instruments.

Freightliner guages troubleshooting

The freightliner system has a vehicle data computer that sends data to the message center in the dash (the rectangular light bar). From the message center, a spider harness sends all data to all gauges, and each gauge selects what it needs to function. Your symptoms sound like corrosion or bad connectors in the wiring. Try reseating the connector from the message center to the spider harness and also check the connectors on the Vehicle Data Computer (it will have two air lines going into it). The Freightliner Help Desk may be able to help. It's a free service ( 1 800 FTL-HELP). Have the last 6 digits of your vin number handy when you call.

There is a history of the Vehicle Data Computer having cold solder joints, but this usually affects only the air pressure guages.

Fred

Fred, Great Freightliner resource.

I had a dashboard gauge problem last month - false low pressure alert. Cleared it by resetting the cable harness, which involved dashboard disassembly.

Which then involved some dashboard maintenance as several of the screw holes were stripped. Which leads me to believe that it has been taken apart in the past, for maybe the same problem?

Which is now leading down the design concept path of installing an access panel for gauge access without disassembly.

Where does one find the Freightliner Service Bulletins? Is there a website? (I will be googling later on as well)

Cheers,

If you have a Workhorse Chassis they had a dash cluster panel recall. The fix is free!

Added via edit: Forgot to mention Welcome to the Forum. You can get a lot of help here.

Suggestion: add a signature line giving us some specifics about your coach. This can eliminate a lot of confusion.

According to the newmar brochure for your motorhome, you could have a ford, workhorse, spartan, or freightliner chassis. All of these will have different systems for the dash instruments.

If you have a ford, workhorse, or spartan chassis, the below info will not help you.

If you have a freightliner chassis, the link below is the troubleshooting guide for your instruments.

Freightliner guages troubleshooting

The freightliner system has a vehicle data computer that sends data to the message center in the dash (the rectangular light bar). From the message center, a spider harness sends all data to all gauges, and each gauge selects what it needs to function. Your symptoms sound like corrosion or bad connectors in the wiring. Try reseating the connector from the message center to the spider harness and also check the connectors on the Vehicle Data Computer (it will have two air lines going into it). The Freightliner Help Desk may be able to help. It's a free service ( 1 800 FTL-HELP). Have the last 6 digits of your vin number handy when you call.

There is a history of the Vehicle Data Computer having cold solder joints, but this usually affects only the air pressure guages.

Fred

IF you have a freightliner chassis, I know what the issue is: The microprocessor that guages engine speed may be bad. This happened to me in 2008. The system logged so many faults that freightliner had a hard time getting through them. There are two sensors involved: Engine Speed and engine performance. Both in horrible locations, but can be fixed. WARNING If this is indeed the problem, be aware that replacing the microprocessor my create an issue with your odomoter.
Have freightliner check it out.

And if the bad ground isn't the issue, there is a brain that controls modern dash gauges. Your chassis manufacturer will be able to lead you to a solution by providing test procedures, diagrams, and schematics.

cableguy574 wrote:
sounds like a lose ground

X-2. When all of the gauges are involved the common factor would be the ground nearly every time.

sounds like a lose ground