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Technical Support / Re: No low beam headlights, High beam okay
« Last post by Scott Shearer on August 27, 2026, 02:13:37 AM »Allen,
Glad you got the low beams working. It is hard to know exactly what caused them to start working again, and issues like this can definitely be frustrating.
Assuming your coach follows the 2007 Patriot wiring diagrams in Coach Assist, keep the following in mind if the issue happens again.
The fog lights also not working suggest that there was no signal from the Smart Wheel Controller to the fog light or low beam relays. The odd thing is that the image you posted of the LEDs on PCB#8 says otherwise. There should have been power at the TS1 low-beam terminal.
On your coach, the Smart Wheel Controller controls the low-beam headlight relay circuit on PCB#8. Unlike some other Smart Wheel applications, the actual low-beam headlamp current does not pass through the controller; only the relay-coil current does.
As you know, the Smart Wheel Controller turns on the low beams when the windshield wipers are turned on. It is possible that turning on the wipers “jogged” the low-beam relay inside the Smart Wheel Controller, although that still does not fully explain the PCB#8 LED indications.
If the problem returns, try gently tapping the Smart Wheel Controller with something like a screwdriver handle.
I did not think about it at the time, but it would have been interesting to know if your coach has Daytime Running Lights and, if so, whether they were functional. The DRL circuit is parallel to, but independent from, the regular low-beam function.
-Scott
Glad you got the low beams working. It is hard to know exactly what caused them to start working again, and issues like this can definitely be frustrating.
Assuming your coach follows the 2007 Patriot wiring diagrams in Coach Assist, keep the following in mind if the issue happens again.
The fog lights also not working suggest that there was no signal from the Smart Wheel Controller to the fog light or low beam relays. The odd thing is that the image you posted of the LEDs on PCB#8 says otherwise. There should have been power at the TS1 low-beam terminal.
On your coach, the Smart Wheel Controller controls the low-beam headlight relay circuit on PCB#8. Unlike some other Smart Wheel applications, the actual low-beam headlamp current does not pass through the controller; only the relay-coil current does.
As you know, the Smart Wheel Controller turns on the low beams when the windshield wipers are turned on. It is possible that turning on the wipers “jogged” the low-beam relay inside the Smart Wheel Controller, although that still does not fully explain the PCB#8 LED indications.
If the problem returns, try gently tapping the Smart Wheel Controller with something like a screwdriver handle.
I did not think about it at the time, but it would have been interesting to know if your coach has Daytime Running Lights and, if so, whether they were functional. The DRL circuit is parallel to, but independent from, the regular low-beam function.
-Scott