Cooling fans inop
Vehicle is overheating but only at idle. Verified no cooling fan operation when the engine reaches operating temperature when they should come on (195 degrees) but I'm relying on my thermal imager with this because of not being able to find ECT temp in my Verus Edge. At the 3 wire thermal switch I have B+ at the red terminal and at the controller KOEO. When I jumper red to red/wht the fan should run but it does not. I manually put power to the fans with a power probe and they run but briefly. It blows the internal fuse in the power probe after about 2 seconds. How can I verify that the fan control module is trying to command the fans on? Would I be able to see this command take place with a lab scope probed at the wire that goes to the fa control module?
Verify the supply voltage under load. The fusebox above the battery will melt at the contacts. Remove the blade fuse to check for burnt spots. Does the compressor clutch work?
as to finding the ECT in data, switch to OBD2, instead of VW.
the fan motors them self are a common problem. I would unplug the fan motors and with some jumper wires see If the fan works.
I ended up piercing the fan motor wiring just because disconnecting wasn't easily accessible and they ran for like 2 secs and blew the internal fuse in the power probe.
...Hey Geoff....Hobbs made it over here...good to see ya's...Dan H.
According to to the diagram you posted the cooling fans should run on low when you jump red to red/wht at the thermo switch. Don't need the cooling fan module for that.
The main fuse in the battery fuse box, should be a bolt in style fuse I made an j fuse adapter to bolt in place, so I could do an amp and voltage test at. But typically it's the fans, and if my fuse area checks out I scope the control wire from the fan module it's a pwm signal, if the fuse is blown, I have found it will do a 2 sec rapid pulse every like 5 sec to keep trying to turn on the fans.
Sean, thanks! Can you elaborate on how you made the fuse adapter?
2 eyelets to bolt too where the fuse bolts then I take the blade butt connectors and wire to eyelets, install blades to 40 amp j fuse. (Or respected size)
I have had many euro fans cause this, where the fan will blow the j case fuse, but with a power probe will spin then short out your tool. i have just done this exact thing on a mini cooper, new fan solves it