Near Intersection of I-35 & I-90 Southern Mn. | EAckerman - 11/22/2012 22:11
Make sure you leave the axle raised when parking the truck. I've got a neighbor with a tandem that has a cheater axle on it. His dad left the axle down and the truck sat for a month before it was used again. The batteries were dead from leaving the axle down. His switch is wired directly to the battery. When the axle is down 12 volts are applied to the air solenoid to keep it open which in turn keeps pressure on the air bags.
I've just been working with this on my tandem truck with a third air axle. My truck is a stretched tractor. Mice got into my wiring forcing me to trace through it. My third axle is actually a front axle taken off a new truck that was converted to FWD. It can pivot to better follow through corners. Backing up with this axle down and loaded could cause excess stress on it.
The power from mine comes from a key source out of the ignition switch and eventually leads to a pedestal mounted beside the seat. This pedestal also houses the air valves for the PTO and Raise/lower functions. This switched power goes to a common single pole single throw toggle switch. The output from this switch leads to the air valve for the tag axle. This wire goes through a relay and uses the N.C. terminal. This relay is triggered by the backup light circuit. This means if the truck is put into reverse, the relay cycles which breaks the circuit to the air valve for the axle. This amounts to it being "OFF" or "UP" when the ignition switch is off, the operator switch is off or the transmission is in reverse.
This pedestal included a light to inform me when the PTO was engaged, I had added a sonalert to this circuit so I would be warned by the sound when the PTO was engaged. Mice had eaten through this wiring causing a fuse to blow which fed the alarm, light and the air tag. The PTO and raise/lower valves worked fine since they are air activated. I was not able to lower the third axle.
I suspected a blown fuse due to the short. After I fixed the short, I was able to get things to work properly by hotwiring that circuit. I was finally able to trace the power source back to the key switch and found an inline fuse which was blown under the dash. I was not aware that this addon fuse was located there. I now plan on making a label to put on the dash to remind me or others of this fuse location. |
Wiring trailer air lift tag in truck
