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Fan controller temp sensor resistance

Yahoo Message Number: 114592
I have seen mention of very different resistance values for the Six pin external sensor controlled set ups. Some of them are given in ohms and some mention kilo ohms. With coolant at about a hundred and fifty Fahrenheit I'm getting 1.1 k ohms on the coolant sensor and 1.3 k ohms on the air temp sensor. Probably around a hundred Fahrenheit in the engine bay, hard to say. Is this normal?

Rich 2002 Magna

Re: Fan controller temp sensor resistance

Reply #1 –
Yahoo Message Number: 114593
Richard:

Higher the engine temperature the lower the ohms, lower the engine temperature higher the ohms.

Kevin Waite
541-953-6162 (Cell)
kvn.wt.7629@...

From: Country-Coach-Owners@yahoogroups.com  on behalf of RICHARD BARLOW rich_barlow@... [Country-Coach-Owners]
Sent: Monday, April 9, 2018 5:16 PM
To: Country-Coach-Owners
Subject: [Country-Coach-Owners] Fan controller temp sensor resistance

I have seen mention of very different resistance values for the Six pin external sensor controlled set ups. Some of them are given in ohms and some mention kilo ohms. With coolant at about a hundred and fifty Fahrenheit I'm getting 1.1 k ohms on the coolant sensor and 1.3 k ohms on the air temp sensor. Probably around a hundred Fahrenheit in the engine bay, hard to say. Is this normal?

Rich 2002 Magna

Re: Fan controller temp sensor resistance

Reply #2 –
Yahoo Message Number: 114594
Thanks Kevin. Yeah, I know that. My question is are the resistance's I'm getting within spec? The chart that I have showing resistance versus temp gives ohm values, not kilo ohms so these are at a much higher resistance. Hopefully I just have the wrong chart.

Rich

Re: Fan controller temp sensor resistance

Reply #3 –
Yahoo Message Number: 114596
Richard,
Did you go to to files section and look at the (fan.pdf ) file? This shows how to test the sensors. If they're bad Kevin sells them. Mine were out of spec, so I replaced them (Kevin supplied them). Didn't help, turns out it was the fan controller. Most people are going to the wax valve replacement. If your interested I post the parts needed to make your own kit for about $400-.
Bill

Re: Fan controller temp sensor resistance

Reply #4 –
Yahoo Message Number: 114598
Bill
Would you please post the parts list for the fan controller.
Bob Cole
2005 Inspire 51394

Re: Fan controller temp sensor resistance

Reply #5 –
Yahoo Message Number: 114602
Bob,

Go here and read this thread. It has a lot of information on the wax valve. Monaco used them in some of their models. This is the same system that Source uses in their wax valve kits. I posted the parts on post #72. It also shows the data sheet for the wax valve.

http://www.irv2.com/forums/f115/fan-stuck-wide-open-376611.html

This is the wax valve Source uses;

http://www.whitehouseproductsltd.com/search-results.aspx?pn=553/1/09857/210

They're about $300 from England. You have to register to see prices.

The only part not listed is the weld on bung. I got mine in Washington state. I'll look it up if you need it.

Bill

Re: Fan controller temp sensor resistance

Reply #6 –
Yahoo Message Number: 114604
Here's data from SD on the two resistance sensors

  Resistance, Ohms Temp , C Temp, F Nom. Tolerance 50 122 810.9 +/- 5% 80 176 283 5% 100 212 152.9 +/-8% 125 257 76.9 +/-8%   

At 150F you should be getting about 500 ohms
At 100F, about 1100 ohms

pete
2000 40' Magna CAT C-10, #5892
Pete
 2000 40'  Magna #5892  CAT C-10

Re: Fan controller temp sensor resistance

Reply #7 –
Yahoo Message Number: 114614
Thanks all. I got the chart. My sensors are right on when engine is cold at about 75 degrees, but they seem to be off at 150F, much higher resistance than the chart shows. That should be making the fan run slower. On the other hand, my engine cycles between 188 and 205 when driving so the fan is cycling. It turns over pretty slow when the engine just starts. I've got to test the resistances at 190 degrees coolant. I think the controller is good, but perhaps as you say one of the sensors has gone out of spec. I was talking to Greg at Country Coach today and he said on our external controlled fans they are basically only two speed fans as opposed to the ECM controlled fans.

Rich 2002 Magna

Re: Fan controller temp sensor resistance

Reply #8 –
Yahoo Message Number: 114620
Cycling between 188 and 205 seems pretty normal. That's about what my temperatures are with the SD controller.
Bill