I am aware that the fan system on the ST170 is beyond questionable for many reasons.

I was suffering this problem for a few weeks, with my car continually blowing the 30A maxi fuse for the fans.

I replaced all fuses relays, complete fan housing and fans and of course the resistor pack temp sensor non of which sorted it although after all this work the fans operated temporarily until the car was moved.

Finally today I found the culprit to be the stupid harness breakout for the engine bay/cylinder head temp sensor which is clearly a Ford after thought

The harness had for sometime been fouling on the coil mounting bracket, photos below of this final solution:















Position of foul condition:


Hope this helps some people!