New Holland T8010 Manual page 1466

Brake Light Relay High Side Driver is Commanded On But No Current Was
Sensed
Possible failure modes:
1. Brake light relay coil failed.
2. Damaged wiring.
3. Loose connector or bent pin.
4. Controller internal failure.
Solution:
1. Locate the brake light relay and replace with a known good relay.
A. Erase the fault code. If the problem does not return troubleshooting is complete.
B. Changing the relay made no difference. Install original relay and continue with step 2.
2. Check the wiring from the AUX/Hitch/PTO controller to the brake light relay. Check for continuity between C054
pin 17 and the brake light relay base pin 1 (F1).
A. If no continuity locate and repair open in wire. Check for continuity between C335 pin 16 and C054 pin 17,
and from C054 pin 17 to connector C010 pin 14 to isolate the open circuit.
B. Good reading, continue with step 3.
3. Check the ground connection at brake light relay base. There should be continuity from relay base pin 2 to
chassis ground.
A. No continuity, repair open circuit in ground.
B. Good reading, continue with step 4.
NOTE: Always inspect connector ends for damage, bent or dislocated pins when troubleshooting.
4. Check the function of the AUX/Hitch/PTO controller. Ignition key ON.
Connect all connections. Make sure the controller has proper power and ground connection.
Depress both brake pedals, there should be about 12 volts at C054 pin 17.
If not, replace the AUX/Hitch/PTO controller.
NOTE: See schematic section 34, 49 and 50 on the schematic poster.
Section 55 - Electrical System, Controller - Chapter 3
AUX/HITCH/PTO FAULT CODE 83
55-3-47