Where do the values on the cards come from?
Every card names its source at the bottom: public references such as NIST Handbook 100, the IEC, ISO and SAE catalogue pages (last checked 2026-11-03), Wikipedia, a Texas Instruments application note, Battery University and a tracker maker's support page. Where a source did not give a value, the card leaves it out.
- Typical values, not guarantees. Your vehicle or device can differ.
- No rating, current limit or pin map for any Tracom device is printed. Those come from the device manual, and the last card is where you write them.
- Left out on purpose: fuse color codes and wire current ratings. Read them from the maker's table.
How do you work out voltage drop on a power wire?
A long thin wire loses voltage. Take the resistance per km from card 1, multiply by the current and by twice the one-way length, because the current goes out and comes back.
Example: 1.0 mm², 2 A, 5 m each way → 0.172 Ω round trip → 0.34 V lost.
How do you check the CAN termination?
Switch everything off and measure between CAN_H and CAN_L with a multimeter.
- ≈ 60 Ω: Two 120 Ω terminators, one at each end
- ≈ 120 Ω: One terminator is missing
- Anything else: check the wiring, the plugs and the length against card 4. The CAN troubleshooter tool turns your readings into a diagnosis.
Can you detect ignition from the battery voltage?
Sometimes. A running alternator lifts a 12 V system to about 13.2 V or more, so a threshold between the parked and running voltage can stand in for an ignition wire.
It can fail on start-stop, smart-alternator and hybrid vehicles. Test on the vehicle, and use the ignition wire or motion when the voltage is not clear.
Limits of the cards
The cards are a memory aid. They do not replace the vehicle manual, the device manual, the maker's instructions or your company's safety rules. Check each value on the vehicle, and never cut or tap a safety-related circuit.