Grain Cart Scale Troubleshooter
Pick your kind of cart - 3-point, walking tandem, 5-point frame, tracks or compression cells. Each one has a hidden problem - the same problems we see on the phone every harvest. Tap a part, use the tests our shop uses, then make the call.
Draft - not yet approved
Loading the troubleshooter... If nothing appears, call 800-582-3175.
The order we work in
- Zero the empty cart and weigh around. Stand on the hitch, then on each weigh bar or load cell in turn. A good bar reads close to your weight; the lightest one is usually the problem.
- Rule the Libra in or out. Unplug the main cable at the Libra box - a healthy box climbs to a high number, typically 700,000 to 1,000,000. Dashes, zero or a frozen number point at the box or its power. See the 60-second test.
- Tap test. Zero, then tap the suspect bar's sensor can with a rubber mallet - never a steel hammer. If the weight jumps and wanders, the bar is bad.
- Meter it. Each pair should read about 350 ohms - green-black and white-red on Weigh-Tronix bars, red-black and white-green on Digi-Star and Agrimatics; about 700 points to the bar, no reading or low points to the cable. See testing a weigh bar with a meter.
- Look it over. Cables pinched, cut or chewed; water or corrosion in the junction box; a tire or hub rubbing; the TOP sticker facing up.
- Know your cart. On a walking tandem, a binding pivot shows the same pattern on both sides, and cables get pinched at the walker. On compression cells, a check rod in a bind lets the frame sit down on a cell. On frame-mounted bars, newer carts are tag up - some older models were built tag-down on purpose. On tracks, set the minimum load to about 1,500 to 2,500 lb.
- Only then calibrate. You can calibrate all day and never fix a bad bar or a mechanical problem.
Found a damaged cable? Practice the splice before you fix it.
More help by symptom: Libra won't weigh right? Start here. Still stuck? Call 800-582-3175.
A simplified simulation for practice, drawn by us. The problems in it come from the calls we took this harvest; your cart's numbers will differ.