Honda Cooling Fan not coming on.

[Timothy Mckeown]

I have a 2004 Honda Civic ex and the cooling fans are not coming on. So far I have replaced coolant temp sensor,coolant fan switch,and the thermostat. The funny thing is if I put a paperclip in the fan switch connector both ac and cooling fans come on. Ihave checked fuses and relays and am at a loss as to what the problem is. Any advice would be greatly appreciated.

Topic

[Dave Tidman]

Given the paperclip test you ran, it seems like the load side (at least from the switch to the fans) is OK. I would start looking at the control side using a wiring diagram and live data. Not real familiar with hondas, but I would check that the coolant temp is being read correctly by the ECM and the see if the signal is sent to close the fan relay. IF that is good, you just need to chase it down the load side to wee where the continuity is lost.

Good Luck.

[Timothy Mckeown]

Thanks Dave,I will check that out. Timothy Mckeown

[Author]

Replies