Chassis Bond
The metal contact point, cleaned of paint and rust, where the negative return path is transferred to the vehicle body. The bond resistance should be as low as possible, typically good enough to give a voltage drop below 0.1 V under load. Its quality determines the stability of the whole system.
A good chassis bond provides three things together: a clean metal surface, sufficient contact pressure and protection against corrosion. Simply tightening the bolt is not enough; the paint, electrostatic coating or rust underneath is an insulator.
- Preparation: the contact area is sanded down to bright metal, and the oxide layer is pierced using a serrated or star washer.
- Terminal: a crimped ring lug is used on the cable end; wrapping the strand directly around the bolt loosens over time.
- Protection: after tightening, the connection is covered with a thin grease or protective coating to keep moisture out. The coating is applied after tightening, not before.
- Verification: the voltage measured between the lug and the chassis while the load is running should typically be below 0.1 V.
All AXI remote controls, drivers and lift kits connect to a negative-chassis system. A significant part of the unstable operation, range loss and unexplained resets encountered in the field comes from a poor-quality chassis bond.
Context in which this term is used: Installation, redundancy and field continuity