The thermo fan on KTM group enduro bikes is controlled by the ECU through a solenoid under the seat. These fans often stop working due to water getting into the connector beneath the fuel tank. Here’s a step-by-step guide to cleaning out the plug.
#1 Remove Seat
Firstly, remove the side number plate to access the seat bolt. Take out the seat bolt and remove the seat.
#2 Unbolt Tank
Next, remove the bolts securing the fuel tank. There is one main bolt in the centre of the tank, plus two bolts fixing the side shrouds to each radiator.
#3 Disconnect Tank
Once the bolts are removed, disconnect the fuel pump wires at the rear of the tank and the fuel line at the quick connector on the side.
#4 Lift Tank
Now lift the tank clear of the bike and set it aside.
#5 Locate Connector
Find the wire connector under the frame that runs to the thermo fan and disconnect it. This plug commonly corrodes, leading to poor or intermittent contact.
#6 Clean Connector
Spray the connector with parts cleaner and blow it dry with compressed air. If corrosion remains, use a wire brush or small piece of sandpaper to clean it before drying again.
#7 Apply Grease
Once clean, apply a small amount of dielectric grease to the connector before reassembling it.
#8 Refit Components
Reinstall the fuel tank, reconnect the wires and fuel line, then refit the seat.
#9 Test Fan
Start the bike and let it idle until the fan kicks in to confirm the repair was successful.
Do’s
• Use dielectric grease on the connector
• Clean all corrosion from the plug
• Replace the connector entirely in extreme cases
Don’ts
• Apply excess force to connectors
• Refit connector without grease
• Pinch wires under the tank when reinstalling
Fan Still Won’t Work?
Beneath the seat are three solenoids: one for the lights, one for the fuel pump, and one for the thermo fan. If the under-tank connector isn’t the issue, the solenoid may be at fault. The plug can corrode when wet, or the solenoid itself may fail and need replacing.
Tools: T-bars, dielectric grease, parts cleaner, air gun
Warning: Keep fingers away from the fan as it can start with enough force to cause serious injury.
