Air brake issues

[brianseay1]

On our return trip home today I got he low air pressure warning light?buzzer on the dash and the #1 air gauge went crazy for about 3-5 seconds and then everything was fine. Couple miles down the road it did it again, then few more miles it cam on and stayed for a couple of minutes and the gauge was reading zero. Then it shot back up to regular pressure and light/buzzer went off. Never had any issues with braking during any of this. I stopped at the first rest area I came to while the light was on, got out to inspect to see if I could find any air leaks. Did not hear anything at all, no smell of heated/burning brakes. I turned the engine off and sat for a few minutes to see if I could get a call in to Freightliner, but had no luck. I was 87 miles from home. So I started back up and everything was fine. the remaining drive home it went off twice for about 5 seconds each time. The batteries are fine, so I'm not really sure where to start looking. Anyone have any ideas on what to check first ? I'm thinking a pressure sensor is going bad. Don't think it is an actual air leak because the air pressure goes back to normal within seconds of it acting up. Any help is greatly appreciated.

[Leeblev]

I had this happen to me on my 2001 Newmar Kountry Star w. Cummins on a Freightliner chassis. What I found out was the microprocessor for the rear air tank became faulty and caused the guage to go to zero, setting off my alarm and scaring the ----- out of me. it would return to normal pressure and do it again and again. Freightliner replaced the processor. When I took it to Freightliner, I had 90000+ on the odometer. When I picked my rig up, it had 46000 on it. The problem was that the microprocessors for the rear air tank, dash and engine (where mileage is stored) miscommunicated and put 45000 on the odometer. Neither Freightliner or Cummins could legally restore the mileage because of federal regulations. Solution? Sticker on door noting to add 44000 miles to the reading on the odometer. Both techs knew how and could fix the problem but legally could not because they didn't want to loose their license. Know and check your mileage before leaving the facility.

[wa8yxm]

Sure sounded like a CNL problem to me (Connection Now Loose) (Pun on the call of a ham radio operator I used to know. The suffix of his call was CNL He said Connecitons NOT loose. we often disagreed on that).

Likely a ground screw somewhere. (not however guaranteed)

[brianseay1]

Just spoke with a guy from Freightliner in Gaffney SC. He said it could be in my wiring harness if I had the white wires (which I do). He said there had been problems with the wiring harness causing faulty readings. Told me I needed to upgrade to the Pollic Jumper Harness (black wires). said the clips were tighter making for a better connection. If that didn't fix it, I could have a gauge going bad.

[brianseay1]

I am on the Freightliner chassis.

[wolfe10]

What chassis?

There have been some failures of the "communication box" between air pressure sender and dash gauges.