Low air fail safe warning alarm not working.

[Rifleman]

Well i have a problem with my low air fail safe warning alarm, the alarm horn does not work at all. Now when you start the truck up with the air tanks empty both the low air warning light and the parking brake light, light up on the dash. If you take off the parking brake the parking brake light turns off and once the air pressure builds up the low air pressure warning light turns off.

Now i pulled the fail safe warning horn and checked the cannon plug to make sure all the pins were making contact and also made sure that the unit had a good ground.

The fail safe warning unit looks brand new and has a date code printed on it, the date printed on the unit is dated around the same time frame as when my truck went through the Red River overhaul process so i think they may have replaced the unit when the truck was overhauled.

Only problem is the horn doesn't work. I tried doing a search on S.S. and came up with alot of leads but none of them helped fix the problem, so what do you guys think the problems is?

I sure don't want to get pulled over for a road side inspection and have the inspector find my low air fail safe alarm not working and getting a fine for it.

 

[usmcm35a2]

Mine would sound for the parking brake, but nothing for low air. I just purchased a 24 volt buzzer off epay for a couple of dollars. I wired the buzzer into the low air light, so when the light flashes the buzzer sounds. Mine looked brand new too, but could not get it to work correctly.

 

[Suprman]

Check the ground wire coming off it. The steering column ground may be in the same place if its not broken take it off anyways and check for corrosion. I had to sand mine a little on the bolt hole and the ground terminal.

 

[rrrr]

Sounds like you need to replace the box. Ericks has them. I had to replace mine when I recovered it.

 

[Rifleman]

Suprfknman,

i did check the ground wire to make sure that it in deed had a good ground. I do agree with your thinking, so many problems in electrical systems can be caused by bad grounds. Case in point all the new cars and trucks on the road today, they all depend on a ton of grounds to complete all their systems. When i use to work on cars and had a customer come in with an electrical problem the first thing i would check would be all the grounds leads. rrrr i think you may be right that it is the warning horn unit itself, i was just hoping that i was missing something but since the warning lights are working it looks like it's time to just buy a new one, i will give Eric's a call and see if they have one in stock. Thanks again guys for all your help