I have a 2008 Thomas school bus it is a front engine flat nose. I am having troubles with my stop sign. When I turn on my 8-ways it will not come out. The switch tells all the nights to come on and flash just no movement from the stop sign. If i pull it out manually to see if it will close itself it will.
Here is what i have checked so far. Some of its overkill but just to be safe I did it.
8-way controller box is works Motor works Micro switch box works Actual 8-way switch works Fuses are all good
I'm thinking next step is going to be tracking down the wiring but I just wanted to see if you guys had any ideas?
the wiring to the stop arm is fairly basic. Red- power supply Blue- trigger wire Ground- I have seen various colors depending on manufacturer
If the stop arm is returning when you shut down the red lights you have power and ground. When the red lights are operating and you pull the stop arm out and it stays out until you shut down the red lights, the arm is receiving the trigger signal on the blue wire. Have you tried changing the two relays inside the stop arm?
Found this with thomas carolina site not sure if this is for your model year
Do NOT disturb any wire connections for these tests as interrupting 12V power to the stop arm relay can cause an intermittent failing relay to start working. We feel the relay has an intermittent issue and are working diligently to prove this. THESE TESTS ARE CONDUCTED WITH THE KEY ON. Step 1: Access the relay by opening access cover behind stop arm blade. Test the red input wire from fuse for full battery voltage (+12V) at the wire. If no voltage check fuse at PDM. It is marked Stop Arm and located in the switch cabinet. Step 2: Test the white ground wire at the relay for good ground at the wire by doing a voltage ground test with digital multi-meter. Step 3: Activate the 8-light warning system and check the blue wire at the relay for full battery voltage (+12V) from the Chassis Hub Module (CHM). If no voltage check fuse at CHM fuse panel. It is clearly marked. Also, check for 0-Volts when the warning system is deactivated. If 0-Volts recorded and lights are on, the relay is bad. Step 4: If any of the previous inputs are incorrect, check the wiring leads to the stop sign lights for breaks or shorts. You can activate the system and move the wire loom to stop arm blade back and forth to see if you can get lights to fail due to a bad loom. Step 5: With all three correctly functioning inputs, check that there is 0 volts on the output wire to the stop arm blade lights with the warning system deactivated. Step 6: With the warning system activated check that there is constant battery voltage (+12V) on the output to the lights on the stop arm blade Step 7: If all of the above checks are OK the lights or light wires to stop arm blade are probably at fault. If steps 5 or 6 do not check out as described the stop arm relay module is at fault.
OEM trained in wiring and all engine platforms for over 20 years