98 Sienna Engine Cooling Fans not operating when engine temp goes up

sim8t3_170340
Sat, 29 Aug 2020 02:26:23 +0000
Maintenance/Repairs

The other day and could hear steam from the top of the radiator and bubbling in the coolant reserve. The engine temperature gauge was almost at red and the fans would not come on, I’m something of DIY guy and handy so I searched online and found how to test the fans by bypassing the relay which in most cases is the culprit, the fans tested fine. One thing though the fans only work with the AC or Defroster on, they won’t turn on when the engine heats up past a certain temp like they are supposed to When you turn on the ignition key you should feel a click on the relay so I had my wife help me test that and the relays checked out. I was wondering since the check engine light hasn’t come on, what are the chances it’s a bad ECT switch? Ive tested the ECT I.E. engine temp sensor with a multimeter shows 2 OHMS and its fine, but it hasn’t been temperature tested since it hasn’t been taken out and it’s not that easy to take out, it requires removing some components I’m not familiar or comfortable removing. I’ve left a message for a local Auto Doc, that makes house calls but I have no idea how busy they are. I would appreciate any suggestions or help as I’m grounded till I solve this problem since it’s the only vehicle we have. Thanks

9 posts - 5 participants