Diesel RV Club, an FMCA Chapter

Technical => Engine Electrical => Topic started by: Captpar on August 03, 2018, 05:09:45 PM

Title: Air pressure gauge
Post by: Captpar on August 03, 2018, 05:09:45 PM
Going to replace air gauge number two next week when it comes in from Freightliner. My question is the air lines glued on or just pull off and push on.
Title: Re: Air pressure gauge
Post by: ziggyh on August 04, 2018, 05:54:43 AM
Be surprised if glued, air lines are usually a compression or a fitting that you push the line in and push in the outer ring to release.  Post a picture.
Title: Re: Air pressure gauge
Post by: Captpar on August 05, 2018, 01:24:10 PM
All gauges stopped working several weeks ago,called Freightliner and they said replace the white wires with the  black ones  (95.00) did that .gauges worked for one day,noticed that transmission temp gauge was erratic while changing wires so I got new gauge (50.00) and geauges worked for one trip then went out again. While unplugging and plugging in wires noticed number 2 air gauge erratic . So ordered a new gauge (200.00). Am awaiting this gauge from Freightliner. In the meantime all gauges are out except the air gauges. I disconnected and cleaned the neg cables on the house batteries.  How else do I check for a ground problem?
Title: Re: Air pressure gauge
Post by: Captpar on August 06, 2018, 01:16:24 PM
When I change out the air pressure gauge should I drain the air tanks before I unplug the air line from the gauge.?
Title: Re: Air pressure gauge
Post by: ziggyh on August 06, 2018, 03:45:44 PM
Are your gauges electric or mechanical, if they are mechanical with an air line attached, yes you would be better off to dump the air tanks so you don't get an air line flapping around like a snake. If your guage has wires only on it then not necessary to dump tanks unless you are replacing an air pressure sensor.

When checking for a bad ground connection I usually put one lead of the voltmeter on the ground post of the battery and the other lead to the ground you are checking, the circuit must be on to do the voltage drop test, any reading of .2 or .3 volts is ok. 

The other method you could use is to simply attach a wire from a good ground or the neg battery post to the ground point of the circuit you are checking and see if there is a change in the operation of the cuircuit you are troubleshooting.
Title: Re: Air pressure gauge
Post by: WallyNM on August 06, 2018, 05:19:05 PM
What year and what chassic
Title: Re: Air pressure gauge
Post by: Captpar on August 07, 2018, 05:40:24 AM
2007 Freightliner