NV Zeno Posted March 12, 2005 Share Posted March 12, 2005 I discovered last week that my radiator fan is not kicking on when the engine heats up. We bypassed the rad sensor and wired the fan to run while the ignition was on (thanks TSJ), worked great. That's what leads me to believe the temp sensor is malfunctioning. Is there some way to test that sensor without removing it from the radiator? Any questions or requests for clarification are also welcome. Link to comment Share on other sites More sharing options...
[HTi]Johnson Posted March 12, 2005 Share Posted March 12, 2005 yeah, disconnect the fan...hook up a multimeter or a continuity tester and let the car warm up. Keep an eye the temp guage, and if the switch doesn't produce continuity somewhere between the midrange and right before the red, I'd say it's bad. Oh yeah, there is no problem to "hardwiring" your fan. But you should rig a switch, inside the car, so you can turn it off before you enter high water...if it is on when you submerse it, say goodbye to you fan and probably radiator. [HTi]Johnson Link to comment Share on other sites More sharing options...
chef_tim Posted March 12, 2005 Share Posted March 12, 2005 Hey Dave, the last one I replaced was $14 from Champion Auto. Tim Link to comment Share on other sites More sharing options...
Skip Posted March 12, 2005 Share Posted March 12, 2005 these are long shots (hopefully it's a Subaru we are asking about) EA81 Check to make sure the grounding strap for the radiator is in place EA82 These switches are prone to going south as the full current of the fan must pass through them (there is no relay for main fan control) Hope you didn't tie this rather large current load to the coil In the future it would be a considerate move to state the car year and engine type, Link to comment Share on other sites More sharing options...
NV Zeno Posted March 12, 2005 Author Share Posted March 12, 2005 these are long shots(hopefully it's a Subaru we are asking about) EA81 Check to make sure the grounding strap for the radiator is in place EA82 These switches are prone to going south as the full current of the fan must pass through them (there is no relay for main fan control) Hope you didn't tie this rather large current load to the coil In the future it would be a considerate move to state the car year and engine type, Skip, you're right, thanks. I erred in not mentioning vehicle type. It's an '83 EA81, California spec. I'll perform the tests recommended above as time permits this weekend, and report here. Thanks guys. Link to comment Share on other sites More sharing options...
Skip Posted March 12, 2005 Share Posted March 12, 2005 it's kewl Dave if you need wiring diagrams or what nots please ask Link to comment Share on other sites More sharing options...
NV Zeno Posted March 12, 2005 Author Share Posted March 12, 2005 I've got an FSM, the wiring looked straightforward. I'm not looking forward to changing the thermo switch, not really in the mood to be dealing with all the coolant mess. On the other hand, this might be the perfect opportunity to flush the system/change the coolant. Thanks. Link to comment Share on other sites More sharing options...
[HTi]Johnson Posted March 12, 2005 Share Posted March 12, 2005 I'm pretty sure he didn't tire the load to the coil. You know the fan doesn;t run when the car is off. He probably just ran some wires from the plug that goes into the switch to a ground. So when the car is on the fan is. Doesn't the thermo switch on EA81s just close a ground when it gets to temp? [HTi]Johnson Link to comment Share on other sites More sharing options...
NorthWet Posted March 12, 2005 Share Posted March 12, 2005 I've got an FSM, the wiring looked straightforward. I'm not looking forward to changing the thermo switch, not really in the mood to be dealing with all the coolant mess.... As long as the rest of the cooling system is sealed (and not hot/pressurized), there should be very little coolant loss if you were to quickly swap the old for the new. Might lose and ounce or two. Link to comment Share on other sites More sharing options...
NV Zeno Posted March 12, 2005 Author Share Posted March 12, 2005 Well, I came home a minute ago, and I heard the fan running. After my "malfunction" last weekend, I had an opportunity to unplug the sensor/switch and clean the terminals. There was lots-o-crud. Didn't think it helped, because I never heard the fan running since then. Guess I never got the engine hot enough to trigger the switch until today. Looks like the simple fix worked. Thanks for all the replies/input. :D Link to comment Share on other sites More sharing options...
pisces_0 Posted November 22, 2006 Share Posted November 22, 2006 Was doing some searching and bumped across a thread that's relevant to one of my newer additions to the Subie. EA82 These switches are prone to going south as the full current of the fan must pass through them (there is no relay for main fan control) Hope you didn't tie this rather large current load to the coil I just removed the mechanical fan off of my '94 Loyale and installed an electric pusher fan in front of the radiator. I wired it up so it kicks on exactly like the stock electric fan. The ground is tied in to the fan temperature switch on the passenger's side of the radiator and the power goes up to the "+" side of the ignition coil. According to Skip this is a no-no? I can easily toss in some relays to protect the temp switch and coil/MPI relay/fuse if need-be. Any recommendations on wiring the additional fan so it kicks on with the stock fan and doesn't damage any of the other electricals? Link to comment Share on other sites More sharing options...
jacobs Posted November 23, 2006 Share Posted November 23, 2006 As long as the rest of the cooling system is sealed (and not hot/pressurized), there should be very little coolant loss if you were to quickly swap the old for the new. Might lose and ounce or two. Yesterday I changed out the switch on my EA82. The engine hadn't been started for at least 2 months but as soon as I loosened the switch, I found there was still pressure in the system. Once the pressure was released, little coolant was lost in the swap. Link to comment Share on other sites More sharing options...
Skip Posted November 23, 2006 Share Posted November 23, 2006 Sir Pisces, A fan of the size you are describing could draw as much as 10 amps when it starts up. I would not tie a load like this to the ignition circuit. Plus fans can make electrical "noise" that the ECU may not enjoy. I'd use the headlight power wire. Remember the headlights get power from the ignition switch and are turned on when the headlamp switch grounds the filament you want to illuminate. What I am saying is that it is also a power source controlled by the ignition switch. Fuse the main power to the relay from the battery. Then tie the relay coil to ground through the temp switch. Hope this helps. Link to comment Share on other sites More sharing options...
pisces_0 Posted November 24, 2006 Share Posted November 24, 2006 Sir Pisces, A fan of the size you are describing could draw as much as 10 amps when it starts up. I would not tie a load like this to the ignition circuit. Plus fans can make electrical "noise" that the ECU may not enjoy. I'd use the headlight power wire. Remember the headlights get power from the ignition switch and are turned on when the headlamp switch grounds the filament you want to illuminate. What I am saying is that it is also a power source controlled by the ignition switch. Fuse the main power to the relay from the battery. Then tie the relay coil to ground through the temp switch. Hope this helps. Yep that wiring method makes complete sense, especially triggering the relay via the temp sensor ground. Looks like I'll be doing a little rewiring on the newly installed fan. Thanks for the input Skip, much appreciated! Link to comment Share on other sites More sharing options...
Skip Posted November 24, 2006 Share Posted November 24, 2006 You are most welcome sir, glad it helped. I would like to clarify one thing I stated. I said " Remember the headlights get power from the ignition switch" This is more correctly stated Remember the headlights get power from a set of relays controlled by the ignition switch. Good luck with the project please ask if you have any other questions. Link to comment Share on other sites More sharing options...
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