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Cooling Fan Switch by msrservices
Started on: 06-05-2014 11:35 PM
Replies: 17 (753 views)
Last post by: msrservices on 06-13-2014 05:22 PM
msrservices
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Report this Post06-05-2014 11:35 PM Click Here to See the Profile for msrservicesClick Here to visit msrservices's HomePageSend a Private Message to msrservicesEdit/Delete MessageReply w/QuoteDirect Link to This Post
Last weekend my temp got up pretty high. I got to where I was going before it got too hot, but it did end up overflowing after it sat.

The fan turns on when the A/C gets turned on.

I can ground the wire at the fan switch (on the motor) and the fan will turn on.

I've let the car warm up and put a test light on the switch. The outside of the switch is grounded, but the center peg never grounds......

I've now put TWO new switches in and neither have worked.

I don't have a way to check the true temp of the engine, but the temp gauge was always accurate in the past.

I'm I just suffering from poor Autozone quality switches? Anything else I can test?

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PaulJK
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Report this Post06-06-2014 04:12 AM Click Here to See the Profile for PaulJKSend a Private Message to PaulJKEdit/Delete MessageReply w/QuoteDirect Link to This Post
It sounds like you have illuminated switches and maybe are using the wrong terminals on the switch (?) Check your switch terminals with your test light / meter - connect 1 terminal to ground. close the switch. use the test light to find the other terminal that is now grounded. now open the switch and see if the test light goes out.

Here's a write-up with pics showing how i did it. Maybe you wanna wire your set-up like i did (?)

http://www.fiero.nl/forum/A...090219-2-084323.html

[This message has been edited by PaulJK (edited 06-06-2014).]

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rogergarrison
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Report this Post06-06-2014 08:22 AM Click Here to See the Profile for rogergarrisonClick Here to Email rogergarrisonSend a Private Message to rogergarrisonEdit/Delete MessageReply w/QuoteDirect Link to This Post
You only need a 2 blade switch. one going to the fan wire and one going to a good ground. I have one on the RV so I can turn it on in traffic or long idles. It still turns on automaticly from factory wiring though too.
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tesmith66
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Report this Post06-06-2014 08:48 AM Click Here to See the Profile for tesmith66Send a Private Message to tesmith66Edit/Delete MessageReply w/QuoteDirect Link to This Post
Are you using teflon tape on the threads? That can keep the switch from grounding. Use a very small amount of pipe dope and check that the switch body is grounded to the intake. All the switch does is ground the pin to the switch body when the target temp (which GM set way too high, but that's another story) is reached. If the switch is insulated from the engine, the fan won't get the signal. You can temporarily jumper the switch body to the engine and see if that works before you go yanking the switch.
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rogergarrison
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Report this Post06-06-2014 12:02 PM Click Here to See the Profile for rogergarrisonClick Here to Email rogergarrisonSend a Private Message to rogergarrisonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Your so right about temps. My Corvettes as well as Fieros had 235* switches. To old school me, thats way too much heat to try and cool down. I always went down to 185*-195* if necessary, and preferred 160* myself. A lot more of a safety factor. Its got to be harder to cool a 250* overheating engine than to keep it down below 200* in the first place. I always figured GM didnt care how long engines lasted after a warranty expired
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msrservices
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Report this Post06-07-2014 01:20 AM Click Here to See the Profile for msrservicesClick Here to visit msrservices's HomePageSend a Private Message to msrservicesEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by PaulJK:

It sounds like you have illuminated switches and maybe are using the wrong terminals on the switch (?) Check your switch terminals with your test light / meter - connect 1 terminal to ground. close the switch. use the test light to find the other terminal that is now grounded. now open the switch and see if the test light goes out.


I'm referring to the stock cooling fan switch located on the engine.


 
quote
Originally posted by tesmith66:

Are you using teflon tape on the threads? That can keep the switch from grounding. Use a very small amount of pipe dope and check that the switch body is grounded to the intake. All the switch does is ground the pin to the switch body when the target temp (which GM set way too high, but that's another story) is reached. If the switch is insulated from the engine, the fan won't get the signal. You can temporarily jumper the switch body to the engine and see if that works before you go yanking the switch.


The replacement switch appears to have a red colored substance on the threads when new. (When I have pulled the switch out, the red color is no longer there.) When I did my tests with a light, the part outside part of the switch is grounded, and gets my test light to turn on, but the inside part that the wire connects to never gets grounded.


 
quote
Originally posted by rogergarrison:

Your so right about temps. My Corvettes as well as Fieros had 235* switches. To old school me, thats way too much heat to try and cool down. I always went down to 185*-195* if necessary, and preferred 160* myself. A lot more of a safety factor. Its got to be harder to cool a 250* overheating engine than to keep it down below 200* in the first place. I always figured GM didnt care how long engines lasted after a warranty expired


The AutoZone switch that I bought doesn't say what temp it's suppose to turn on at, but it does say that it fits my car....not that fitting my car means that it actually works like OEM.

I have ordered the Fiero Store switch and hope that will fix my problem..... I don't really want to have to do manual switch (especially since it was all working up until last weekend.)
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Patrick
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Report this Post06-07-2014 01:50 AM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post

Should've bought the fan switch from Rodney that turns the fan on at 210° (instead of 235°). Works great.
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msrservices
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Report this Post06-09-2014 05:40 PM Click Here to See the Profile for msrservicesClick Here to visit msrservices's HomePageSend a Private Message to msrservicesEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm stumped. I've now replaced my fan switch three times!

When I let the car warm up, the switch never turns on.

Again, I can get the fan to turn on if I ground the wire that connects to the fan switch (which is located on the engine.)

When I check the switch, I use a test light. The outside of the switch will be grounded, but the inside (the part that connects to the wire) never grounds.

Thoughts?
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Patrick
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Report this Post06-09-2014 06:12 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by msrservices:

When I let the car warm up, the switch never turns on.


It was also my experience when I had the factory fan switch (235°F) that the fan would never come on (with a 195°F thermostat). That's why I swapped over to the one I linked to in my previous post.

[This message has been edited by Patrick (edited 06-09-2014).]

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GodSend
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Report this Post06-09-2014 06:28 PM Click Here to See the Profile for GodSendClick Here to Email GodSendSend a Private Message to GodSendEdit/Delete MessageReply w/QuoteDirect Link to This Post
Currently battling EXACTLY the same problem. Multiple fan switches, grounding wire works, works with flick of the ac button. Installed new pigtail just incase. No Teflon tape used and I used a pick to clean out any left overs from a previous install.

Could there be something blocking the coolant reaching the sensor?
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Patrick
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Report this Post06-09-2014 06:42 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post

Guys, unless there's a reason why you suspect your coolant is exceeding 235°F, there may be absolutely nothing wrong with the fan switches you have installed.

Have you scanned your warmed-up engine to see what the actual operating temperature of the coolant is?
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Report this Post06-09-2014 08:14 PM Click Here to See the Profile for GodSendClick Here to Email GodSendSend a Private Message to GodSendEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:


Guys, unless there's a reason why you suspect your coolant is exceeding 235°F, there may be absolutely nothing wrong with the fan switches you have installed.

Have you scanned your warmed-up engine to see what the actual operating temperature of the coolant is?


I have using my diagnostic cable. Also I can almost pinpoint the day this began happening. The gauge would never read over a certain point on the gauge, and now it travels significantly further. I have never actually let it overheat, but I am not anxious to find out if that happens. I will do another scan tool shortly.

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Patrick
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Report this Post06-09-2014 08:22 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by GodSend:

I have using my diagnostic cable... I will do another scan tool shortly.


Find out the actual coolant temperature. You might be surprised.
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msrservices
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Report this Post06-09-2014 08:28 PM Click Here to See the Profile for msrservicesClick Here to visit msrservices's HomePageSend a Private Message to msrservicesEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:


Guys, unless there's a reason why you suspect your coolant is exceeding 235°F, there may be absolutely nothing wrong with the fan switches you have installed.

Have you scanned your warmed-up engine to see what the actual operating temperature of the coolant is?


I will have to get my hands on a temp gauge. I was under the impression that if the coolant overflows the overfill, then it's reaching the high temp. As I mentioned, the I know that the fan had worked in the past, as I've seen it.

In the past my stock temp gauge was always pretty accurate and the fan would always turn on at the same time.... I'll check the actual temp.
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Patrick
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Report this Post06-09-2014 08:33 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by msrservices:

I was under the impression that if the coolant overflows the overfill, then it's reaching the high temp.


Not necessarily. Rad caps fail (and air in the system will also cause it to puke coolant).

[This message has been edited by Patrick (edited 11-11-2014).]

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GodSend
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Report this Post06-10-2014 03:34 PM Click Here to See the Profile for GodSendClick Here to Email GodSendSend a Private Message to GodSendEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:

Find out the actual coolant temperature. You might be surprised.


What is the relationship between the gauge and the temp. warning light? Is the light triggered by the ECU or are they both driven by the Coolant Temp Sensor?

The reason I ask is because I was having a bear of a time getting my winaldl up and running last night. As I was fiddling with the cable and letting the car idle the temp gauge continued to climb (this takes awhile, about 15 minutes?) to the point that the warning light came on. At that point I quickly turned the AC on, and watched the gauge come back to "normal range" based on my now 10 years of fiero ownership (which by no means makes me an expert, but certainly this behavior is not normal).... Normally I don't let it get to that point, but I was curious what would happen..

[This message has been edited by GodSend (edited 06-10-2014).]

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GodSend
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Report this Post06-10-2014 04:40 PM Click Here to See the Profile for GodSendClick Here to Email GodSendSend a Private Message to GodSendEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by GodSend:


What is the relationship between the gauge and the temp. warning light? Is the light triggered by the ECU or are they both driven by the Coolant Temp Sensor?

The reason I ask is because I was having a bear of a time getting my winaldl up and running last night. As I was fiddling with the cable and letting the car idle the temp gauge continued to climb (this takes awhile, about 15 minutes?) to the point that the warning light came on. At that point I quickly turned the AC on, and watched the gauge come back to "normal range" based on my now 10 years of fiero ownership (which by no means makes me an expert, but certainly this behavior is not normal).... Normally I don't let it get to that point, but I was curious what would happen..



Google answered my question. Let me take a look at the CTS and see what is up with that.
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msrservices
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Report this Post06-13-2014 05:22 PM Click Here to See the Profile for msrservicesClick Here to visit msrservices's HomePageSend a Private Message to msrservicesEdit/Delete MessageReply w/QuoteDirect Link to This Post
Installed Rodney's low temp switch and thermostat. My fan now turns on... much lower than the stock.
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