Would somebody be so kind to tell me where the electric signal to the rear air gauge comes from. My rear air is pegged at 180, switched gauges and the same. Thanks Tom
Tom,
There are two air tanks underneath the front end of the coach. On supplies air to the front brakes the other to the rear brakes. An air line from each goes up into the dash in front of the driver's seat to the "blue module" where aire pressure is converted to an electrical signal which goes to the gauge. Blue module failures are common. The parts are likely no longer available. Most just put a T in the air line and run an air line to a mechanical air pressure gauge. See the following thread.
"Blue Module" Failure (http://www.foreforums.com/index.php?topic=15135.msg95524#msg95524)
It is very unlikely that the rear tank actually has 180 psi. If you switched the electrical leads between gauges and the other also reads 180 psi then the likely problem is the blue box.
My 2001 was just before the blue box era, I had the gray box. Same problem, similar fix with mechanical gauges.
Roger
Search the Forum for Blue Module
Look at that! Thanks for the picture, Barry.
Thanks very much. I guess mech gauges are in order. Tom
Tom, I used VDO gauges. They work fine and are easier to read than the originals. White bulbs with red and green covers for those colors of back light.
http://www.egauges.com/SearchResults.asp?Search=150-105&Submit=Search (http://www.egauges.com/SearchResults.asp?Search=150-105&Submit=Search)
150-105 Black Front
150-106 Black Rear
You will need a 1/4" tubing kit or you can get the parts you need at a good hardware store (probably for less). I needed to go directly to the tanks and of course one kit got to the front tank and I was 2' short to the rear tank.
If anyone wants to mail one of these blue modules and the associated gauge to me I'd be happy to take a look. Often these electronics can be pretty easily repaired by replacing capacitors and other bits.
Thanks Roger, those are the exact ones I ordered yesterday.
The curved side of the dash towards the window sort of snaps into place, no mechanical fasteners on mine which should be like yours. It takes a thin prying tool (a couple inches wide) and some courage the first time you open it up and then what you need to get at is pretty much right there. It pops up and out at the bottom first as I recall.
Roger