[andrewInBriz]

Hello from Australia. No chance of snow at all.
I've had a manual fan switch for about 3 years (off the relay wiring. No previous problems). Has stopped working.
No fault codes. Not run it hot enough for the ecu to trigger the fan. Not tested the coolant temp sensor. This would not effect the manual fan switch operation.
Checked fan fuse.
Have tested the fan. Works ok.
Have tested the relay. Works ok.
Have tested the manual switch. Works ok.
Was a little corrosion on the fan connector. Cleaned.
Checked the ecu. No obvious signs of wiring damage. My wiring diagram doesn't match the wire colours on the ecu? Where does the fan relay connect on the ecu?? Upper I presume. Black or Grey ecu?
Anyone with electrical experience?
Do I check continuity between relay (which pins?) and fan connector?
Continuity or other test between relay and ecu (which pins?)?
Any help appreciated. Electrical issues are not my thang.
Thanks for any help.

 

[andrewInBriz]

Doh! Solved. Continuity between manual switch and from wires tapped into relay connector, but not from one of the wires in the connector out to the manual switch. Long time for cold solder joint to show, or maybe lust a result of vibration.
But for manual fan switch users, look at your joints.

 

[john kinzell]

Hello from Australia. No chance of snow at all.

NO snow.. that sucks!!!
Drop in to northern Kanada in Dec-Jan.. snow ball dragin deep to a tall eskimo!!
Good to see ya figgered out yer prollem, keep up da gud wurk..

B well