front and rear brake pressure gauge shows diffrent pressures

Hello all!
I have a strange problem with the air brake pressure gauges. Pressure is about 120psi on all 3 tanks, CTIS is working well, but the 2 pressure gauges shows front brake 90 psi, and rear brake 120 psi. Does anyone had a same situation? The 2 pressure transducer are near the left front wheel, behind the bumper right?
Maybe it's a transducer problem, or wiring?

Christian

The transducers are under the drivers dash. I have seen their contacts rub on part if the dash. Sometimes the housings loose their ground. Could be the gage though.

Yep, under dash. You should be able to swap gauge signal lines between sensors to determine wether it is a gauge issue or a sensor issue. Since they vary resistance of a pathway to ground, make sure the connections from the sensor to ground are good. A bad ground could cause a gauge to read low...

the sensors also provide a contact closure to activate the brake idiot lights on the panel, so don't mix up the wires... They are shown on the schematic at F 177.

I see so many trucks with odd gauge issues most related to ground issues. The senders are grounded thru a bolt going to a dash bracket. I see alot of them intentionally unbolted the low air buzzer will come on in error with the housing grounded.