Radiator Fan Problem
10-14-2002, 10:07 PM
#41
Junior Member
Posts like a Ricer Type-R
Thread Starter
Join Date: Oct 2002
Location: Wichita, Ks
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
Good idea, Will. I'll try the boiling water experiment. It'* probably going to be Thursday evening before I can play with it, though... tomorrow and Wednesday nights, I have to some "Dad" things. I'll get back to you, with the results.
Thanks
-Roger
Thanks
-Roger
10-20-2002, 04:31 PM
#42
Junior Member
Posts like a Ricer Type-R
Thread Starter
Join Date: Oct 2002
Location: Wichita, Ks
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
Will and Rat -
Bad news and good news.
First, I purchased a new Coolant Sensor. Before I installed it, I tried the boiling water experiment, to see if I could get the low speed fan to come on. The wiring harness doesn't provide much slack, but I was able to squeeze a cup of boiling water in there, under the throttle and vacuum hoses, and I dunked the new Coolant Sensor for awhile. No joy... couldn't get the fan to come on. Which made me worry that there could still be something wrong upstream.
So, what the heck... I just replaced the Coolant Sensor, anyway. Guess what... it worked!
Temp cycles up to almost 220, low speed fan(*) come on, temp falls back to 200, fans drop out. And the low speed is on both fans, not just the drivers side fan. So, maybe the fan relays are wired so that one relay is low speed (both fans) and the other relay is high speed (both fans)... not sure about that, but I wouldn't be surprised.
Anyway, problem solved... thanks for all the help.
BTW - I'm still planning on a 180 thermostat, but will probably wait until spring.
-Roger
Bad news and good news.
First, I purchased a new Coolant Sensor. Before I installed it, I tried the boiling water experiment, to see if I could get the low speed fan to come on. The wiring harness doesn't provide much slack, but I was able to squeeze a cup of boiling water in there, under the throttle and vacuum hoses, and I dunked the new Coolant Sensor for awhile. No joy... couldn't get the fan to come on. Which made me worry that there could still be something wrong upstream.
So, what the heck... I just replaced the Coolant Sensor, anyway. Guess what... it worked!
Temp cycles up to almost 220, low speed fan(*) come on, temp falls back to 200, fans drop out. And the low speed is on both fans, not just the drivers side fan. So, maybe the fan relays are wired so that one relay is low speed (both fans) and the other relay is high speed (both fans)... not sure about that, but I wouldn't be surprised.Anyway, problem solved... thanks for all the help.
BTW - I'm still planning on a 180 thermostat, but will probably wait until spring.
-Roger
10-20-2002, 05:00 PM
#43
Junior Member
Posts like a Ricer Type-R
Good deal! I'd be curious to see what both thermistors read while at the same temp. Did you try that?
Yes, you're right about the schematic. Both low, or both high. Low and High relays. Thanks for the extra knowledge!
Yes, you're right about the schematic. Both low, or both high. Low and High relays. Thanks for the extra knowledge!
10-20-2002, 05:46 PM
#44
Senior Member
Posts like a Northstar
Join Date: Sep 2002
Location: Lansdale, pa
Posts: 762
Likes: 0
Received 0 Likes
on
0 Posts
I got a problem now , Last week the car would run at around 170 degree'* now it'* gone up to 200 degress'* . Before the fans used to be on mostly all the time , now I can only catch them on with the A C , is this normal or shoul they be on only at high temps , Like I said they used to be on mostly all the time
P * - how much did you pay for the coolent sensor?
P * - how much did you pay for the coolent sensor?
10-20-2002, 06:07 PM
#45
Junior Member
Posts like a Ricer Type-R
Thread Starter
Join Date: Oct 2002
Location: Wichita, Ks
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
vze3r85p -
Just to recap what we learned in this (long) thread:
- Fans will always come on (high speed) when the AC is on, or the defroster is on. This mode bypasses the coolant sensor.
- With AC or defroster off, (low speed) fans should come on at about 220 degrees, and shut off at about 200 degrees.
Maybe the reason you heard the fans on all of the time until recently.. was because you had the AC on all the time. That'* what happened in my case... I didn't realize I had a cooling issue until the fall, when I quit running the AC.
I'd have to go back to look at the price on the coolant sensor, but as I remember, it was relatively cheap. Maybe under $20.
-Roger
Just to recap what we learned in this (long) thread:
- Fans will always come on (high speed) when the AC is on, or the defroster is on. This mode bypasses the coolant sensor.
- With AC or defroster off, (low speed) fans should come on at about 220 degrees, and shut off at about 200 degrees.
Maybe the reason you heard the fans on all of the time until recently.. was because you had the AC on all the time. That'* what happened in my case... I didn't realize I had a cooling issue until the fall, when I quit running the AC.
I'd have to go back to look at the price on the coolant sensor, but as I remember, it was relatively cheap. Maybe under $20.
-Roger
08-19-2006, 03:59 PM
#47
Member
Posts like a V-Tak
Originally Posted by willwren
About every 20° change equals about a 100 ohm difference in thermistor resistance. For instance, 212°F is 177 ohms, and 194° is 241, 176 is 332, and so on. As you get to the bottom of the scale, it'* not so linear, but we don't care, because the fans come on at the higher range, right? So if you want your fans to come on at 20° cooler, you simply splice a 100 ohm resistor in series with the thermistor. The same trick can be done with the IAT.....if fact, kits for the IAT are sold commercially. You can do it yourself quite simply. Try this one.......you can use a switch to make them come on when you want, but then again, auto is better.
Thread
Thread Starter
Forum
Replies
Last Post
jlathem
Performance, Brainstorming & Tuning
14
09-28-2004 12:08 AM