Fan thermo switch; is this right? (cheap FIX?)
Posted: Wed Aug 08, 2007 4:10 pm
Revised 28 July 2008. Please read my advice in This Post. I no longer believe that the cheap mode is profitable.
Cycleman used his scientific method to break down an Alternative Fan Switch. Read his string of posts if you really want to do this. Cost is about the same as OEM. 5 Feb '09.
Mark King came up with a way to Repair a Switch. This might be worth a try. 11 Aug '11
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Am I doing this right?
I'm not getting any action out of the fan or temperature gauge. The gas gauge is working correctly.
Starting with the fan switch ... The radiator has been removed and the fan runs good when directly connected to the battery. So I pulled the switch out of the outside part of the thermostat housing (the one with two poles on it). I hung it in engine oil, clipped on the candy timer (yeah, it's okay, the wife is out at the stable playing with her horse) and cranked up the heat.
[attachment=0]fanswitchtestfd2.jpg[/attachment]
My tester is set on 200 ohms resistance. The Haynes manual says:
Switch open (no continuity) from 198° to 207° F
Switch closed (continuity) from 208° to 215° F
I checked from 175° all the way up to 250° and there was no change on the tester.
So, are my tester settings correct? Is the switch bad?
Later that day ... ...
Still no luck on the fan switch test. With both leads moved down one hole I get a reading of 0.3-0.2 when touching the leads together. But still no movement when testing the switch.
Good news is ... I pulled the temperature sensor and tested that (as long as I got the kitchen to myself ) and as the temp went up the ohms went down. Not exactly the same numbers as the book but close. Mine were running about 10 higher. That prolly means wiring to the gauge or the gauge itself, eh?
But I'm still confused about the fan switch test. My Haynes manual says, "Test the switch by using a similar method to that detailed in the previous Section for the temperature gauge sensor switch and check that the temperatures at which the switch opens and closes correspond with those given below.
"Switch open (no continuity) from 198° to 207° F
"Switch closed (continuity) from 208° to 215° F
"If the reading obtained differ, then the sensor switch must be renewed."
I love the part "using a similar method". And what about below 198° and above 215°F?
But, I'm not getting any readings at all. Am I reading too much into this? It should just indicate ON/OFF, right? Maybe I need a palm reading. Let's all go jump on the Reading Railroad....
.
Cycleman used his scientific method to break down an Alternative Fan Switch. Read his string of posts if you really want to do this. Cost is about the same as OEM. 5 Feb '09.
Mark King came up with a way to Repair a Switch. This might be worth a try. 11 Aug '11
___________________________________
Am I doing this right?
I'm not getting any action out of the fan or temperature gauge. The gas gauge is working correctly.
Starting with the fan switch ... The radiator has been removed and the fan runs good when directly connected to the battery. So I pulled the switch out of the outside part of the thermostat housing (the one with two poles on it). I hung it in engine oil, clipped on the candy timer (yeah, it's okay, the wife is out at the stable playing with her horse) and cranked up the heat.
[attachment=0]fanswitchtestfd2.jpg[/attachment]
My tester is set on 200 ohms resistance. The Haynes manual says:
Switch open (no continuity) from 198° to 207° F
Switch closed (continuity) from 208° to 215° F
I checked from 175° all the way up to 250° and there was no change on the tester.
So, are my tester settings correct? Is the switch bad?
Later that day ... ...
Still no luck on the fan switch test. With both leads moved down one hole I get a reading of 0.3-0.2 when touching the leads together. But still no movement when testing the switch.
Good news is ... I pulled the temperature sensor and tested that (as long as I got the kitchen to myself ) and as the temp went up the ohms went down. Not exactly the same numbers as the book but close. Mine were running about 10 higher. That prolly means wiring to the gauge or the gauge itself, eh?
But I'm still confused about the fan switch test. My Haynes manual says, "Test the switch by using a similar method to that detailed in the previous Section for the temperature gauge sensor switch and check that the temperatures at which the switch opens and closes correspond with those given below.
"Switch open (no continuity) from 198° to 207° F
"Switch closed (continuity) from 208° to 215° F
"If the reading obtained differ, then the sensor switch must be renewed."
I love the part "using a similar method". And what about below 198° and above 215°F?
But, I'm not getting any readings at all. Am I reading too much into this? It should just indicate ON/OFF, right? Maybe I need a palm reading. Let's all go jump on the Reading Railroad....
.