Temperature Sensor¶
The alternator temperature sensor is a digital temperature sensor (DS18B20) factory-sealed into a copper ring lug on a 0.5 m lead. Three are included with the regulator — identical except for lug hole size: M4, M5, and M8. Use whichever one fits the hardware on your alternator case best. The other two are spares.
Mounting¶
- Pick a bolt or stud on the alternator case itself, as close to the rear bearing / stator housing as practical. That is the hottest accessible metal and tracks winding temperature best.
- Use grounded case hardware only. Do not mount the lug on the output stud (B+) — the lug barrel is conductive.
- Remove the nut or bolt, slip the lug on, and retighten. The lug should sit metal-to-metal against the case — no washers between the lug and the case.
- Route the lead clear of the belt, pulleys, and exhaust components, and secure it so engine vibration cannot work it loose.
Wiring¶
The sensor has three leads. They connect to Cable 1 (the right RJ5 port as you face the connectors, alternator side):
| Sensor lead | Cable 1 wire | Function |
|---|---|---|
| Red | Orange/White | 3.3 V power |
| White | Green/White | Signal |
| Black | Orange | Ground |
The complete pinout for all four cables is in Data Cables & Pinout.
Confirming it works¶
Power the regulator and open the dashboard. The alternator temperature reading should appear within a few seconds of boot. The Temp Source setting should be set to Digital — this is the factory default, so no configuration is needed.
Set the alternator temperature alarm limit during Initial Settings.
Other sensor options¶
The regulator also accepts a 10 kΩ thermistor as an alternative temperature source (not recommended — the digital sensor is more accurate where it matters), and other thermistor resistances are possible with a single on-board resistor change. The full comparison of sensor options, including an untested analog alternative, is in Hardware → Sensors → Temperature Sensors.