What should I do if the tractor's other electronics are affected while the kit is running?
The current the DC motor draws at start-up can momentarily pull the line down; radio crackle or a flickering gauge usually comes from this. The remedy is to take the kit's supply close to the battery terminal and through its own fuse, to choose a wire cross section of at least 2.5 mm² for a 10 A load, and not to take the chassis earth from the same loose point as sensitive devices.
There are two mechanisms:
- Voltage drop: The motor draws a brief high current at start-up. If the wire is thin or the route long, the line voltage dips for an instant and devices sharing that line are affected.
- Brush noise: Brushed DC motors produce broadband noise; if the wires are run parallel to sensitive signal wires, interference occurs.
What to do:
- Take the supply straight from the battery terminal through its own fuse; do not connect it in parallel with the supply of sensitive devices.
- Do the cross-section calculation: at 12V a 3% voltage drop leaves only 0.36 V of margin; for a 10 A load and 3 m one-way distance, at least 2.5 mm² (about 14 AWG) is recommended.
- Run the positive and negative wires together and twisted; avoid long routes parallel to signal wires.
- Make the chassis connection to clean bare metal, short and at a single point.
If the effect persists after these measures, check whether another consumer shares the same supply point.
Full topic: Converting a tractor hydraulic lever to electronic control