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View Full Version : 94 SC Auto - Cooling Fan help



Tim Groth
07-04-2009, 03:37 PM
Need some help troubleshooting the cooling fans on my 94 AUTO SC. I'll list out what I've done and well what I am working with car wise also.

Picked this car up last week super neglected...runs smooth and strong but wants to over heat.

Upon purchase fans only came on with AC on or ECT sensor disconnected. I've replaced both the IRCM and the ECT w/ known good units. The fans now come on, on there own however the temp guage is usually past the M of NORM when they do.

Car has an LX cluster w/ VOLT guage in center..so not sure the accuracy of the cluster. Have known good cluster from parts car to swap in.

I've read on several other posts that the culprit may be the EEC but if fans are coming on (even tho when really hot) I assume the EEC is working as it should.

Other Items I will address - Replace T-stat, Flush Coolant System, replace cluster w/ 94 SC cluster.

Anything else I may be missing here in determining whats wrong. Trying to save another SC from the ashes.

-Tim

Pablo94SC
07-05-2009, 05:37 AM
First, here's a link to my 94/95 cooling fan FAQ I started working on.

http://www.sccoa.com/forums/showpost.php?p=747842&postcount=6

Now then... Are both low and high speed windings on the main and the aux pusher fan cycling on during KOEO? You should here whrrr, WHRRRR, Whrrrr. If not, you have a problem somewhere.

Next, check the connection to the coolant temp sensor on the goose neck. If it's loose or corroded, you might be getting a false reading on the cluster.

Finally, Dave or someone who knows for certain should chime in here, but I'm pretty sure the low speed winding kicks on at like 200*, high speed at like 210*, and aux at like 230 or something ridiculous. I have a switch grounding out its relay (DS inner fender near the fire wall/master cylinder... can't miss it... only relay there) to kick it on anytime I want.

Stock thermostat is like 197* so installing a 180* might not hurt, but it might not help either unless you get the fans to kick on sooner. Running a thermo-electric switch to turn the fan on earlier works, but you have to be able to kill the low speed winding when the high speed kicks in, otherwise you'll burn up the fan motor.

Oh yeah, also check and make sure the front diffuser (bolts to bumper cover) and chin spoiler are still in place and in good shape. You can easily lose the spoiler and I've worn a hole in the front of the diffuser as well from pulling up to far and scraping parking lot stops and curbs at strip malls.

Call me tomorrow if you have any questions (901-486-7009).

fturner
07-05-2009, 08:17 AM
1. On all years, the low speed mode is set to come on at 220F and shut off about 4 degrees lower, and the high speed mode is set to come on at 228F and transition back to low speed at 4 degrees lower.

2. From 89-94 (yes 94) had a dual speed puller fan which handled both modes.

3. The 94-95 years got a pusher fan that ran in high speed mode. The "auxilary" fan mode was only used in the 94 to run the high speed mode of the puller fan as mentioned in 2. Ford removed that optioin in the 95's.

It is highly recommended if going to a 180 tstat to get a chip and have the fan on temps lowered accordingly. I would also recommend the same for a 197 tstat as it can make a difference there as well. There has been alot of reports proving that running a 180 tstat and leaving the stock fan on temps causes the car to run alot hotter and over heat. This is because there is not enough sitting time in the rad and insufficient air flow to cool the coolant so everything becomes heat soaked and the temps keep rising. Thats the problem with running a small rad like ours.

If you are experiencing problems with the fans, do the trouble shooting as mentioned and fix it. Don't start cutting wires etc. Replace the IRCM if need be and the EEC if that doesn't fix it. If the car cannot get over 180F you are not getting the benefits of running with adaptive learning etc and will more than likely end up running with a rich condition.

Fraser

Tim Groth
07-05-2009, 12:23 PM
Alright, installed the new cluster...with known good one from the parts car I have. Flushed the radiator and refilled w/ 50/50 mixture.

Car still runs warmer than it should. High speed fan kicks on when past the M...I will run the KOEO today, I have the tester somewhere around here.

I've never seen the pusher fan come on...when does this fan normally engage? Also Pablo...your write up lists wiring that fan to be on at all times....will this have any negative effects by doing so. Below is the snippet I'm referring too.

Temp Solutions/Quick Fixes
Pusher Fan
1. Ground the trigger wire (Orange/Green) to run fan at all times Key ON. Switch can be installed to open/close ground for manual control.

I have another 94/95 EEC that I can replace current with, however again fans are engaging so I feel that it's working as it should.

I have an extra T-stat housing laying around, I'll change out the sensor for the gauge and see what I get.

Thanks for your help in hunting it down.

-Tim

sinhumane
07-05-2009, 12:53 PM
i'm going to follow this. both of mine run right around this temp, its never really bothered me, and its with a 192 thermostat, KOEO turns low speed on, then high. my 95 has the pusher fan removed, the 94 auto i have has it still there because it works.

Mike8675309
07-05-2009, 03:02 PM
Running the low speed fan by grounding it can lead to problems if the high speed fan comes on. Instead you need to make sure the low speed fan goes open if the high speed fan comes on.

While I feel it can help some folks, I generally don't recommend running the fan all the time with key on. Granted the fan motor was old on my 90, but after two years of having the fan come on with the key, the motor melted down on my way to work one day burning up the fan motor and the connector to the fan.

In general, i believe running the fan all the time is going to lead to a shorter life with the cooling fan.

Tim Groth
07-05-2009, 05:03 PM
Running the low speed fan by grounding it can lead to problems if the high speed fan comes on. Instead you need to make sure the low speed fan goes open if the high speed fan comes on.

While I feel it can help some folks, I generally don't recommend running the fan all the time with key on. Granted the fan motor was old on my 90, but after two years of having the fan come on with the key, the motor melted down on my way to work one day burning up the fan motor and the connector to the fan.

In general, i believe running the fan all the time is going to lead to a shorter life with the cooling fan.

I've read this also...some threads from 2004...perhaps started by you actually. I understand the Low Speed and the High Speed motors are both in the Puller Fan....I was asking more about the "Pusher" fan. Any issues with this?

If I read correctly by wiring the Low on all time...it's not supposed to be on with the High speed fan kicks in...and well doing it that will can cause them to burn up. Correct?

-Tim

Mike8675309
07-05-2009, 06:14 PM
If I read correctly by wiring the Low on all time...it's not supposed to be on with the High speed fan kicks in...and well doing it that will can cause them to burn up. Correct?

-Tim

Correct. The cooling fan has dual windings in it. One that causes the fan to spin slower, one to spin the fan faster. The high speed fan windings are not sufficient to get the fan spinning from a stop, thus the high speed will never come on without first energizing the low speed. Then when the high speed is called for, the low speed is shut off at the same time. Providing inertia for the high speed windings to take over.

Here is a link to a thread where I had dug up some info on the pusher fan:
http://www.sccoa.com/forums/showthread.php?t=17424&highlight=pusher+fan+turn
The original thread was here:
http://www.sccoa.com/forums/showthread.php?s=&threadid=23695

Tim Groth
07-05-2009, 06:33 PM
Reading what Jimmy2Coupes posted...it sounds as though it's normal for the Temp to climb to the M in NORM and then the fans kick on. So with that being the case, my car is cycling just as it should.

It's been a while since I've drove a 94-95 SC model...my 93 would usually climb between the O/R of NORM so being past the M it made me raise a red flag.

Thanks for the FYI...I wasn't aware the "pusher" fan is just for emergency purposes. Still might wire it up to run all time just for good piece of mind.

-Tim

Pablo94SC
07-05-2009, 07:00 PM
I'll give you a quick response here so everyone has access to it, but give me a call Tim if you have any more questions.

There's no adverse effect to this except the constant draw of power when the key is in the ON position and the fact you're using a fan above 45mph which is almost pointless.

I run mine below 45mph around town when the A/C is on. Switch it off the rest of the time. I have it wired up to my fog light switch since I removed those years ago. When the switch is OFF, the computer will still control the fan's operation, which stock is pretty much never. :rolleyes:

A couple other things I've found that will seriously help the cooling on the 94/95 cars...

1. I lost my chin spoiler long ago and made a new one out of a 1/8" x 2" x 36" (maybe 48") bar of aluminum stock from Home Depot Performance and some light gauge 1.5x1.5" (or was it 2x2"?) right angle brackets. Use the light gauge brackets only to allow the spoiler to bend, otherwise you could pull off the front diffuser from the bumper cover if you bottom out on a driveway or pulling up to a curb. I'll take pics and post them later so you can see the location I mounted it at. With my old stock radiator, this really improved the amount of air getting to the cores and helped keep me around NO.

2. When my car was on the dyno, I noticed a significant amount of air was blowing up and out around the header panel and NOT through the cores. The early models have a small rubber-type dress plate that goes around the hood latch. It was there for a reason, and why it's not on the late model cars is beyond me!

Making a dress plate for that location should help force more air through the cores and not allow it to go up and over the upper radiator support. I'm in the process of making up a template and trying to find someone local who has the tools that can help me cut and shape this piece properly. Once I do and see how well they work, I'll offer these for sale for our cars.

3. Get some weather stripping and insulate the radiator from the upper radiator support to keep air from bypassing like above, as well as closing off the gaps around the fans and the cores (aux has a finger width one on the PS).

4. Get a new radiator cap every year or two.


Side note... anyone relocate their washer fluid reservoir? I hate the fact it's in front of the IC but I can't figure out where to put it or an aftermarket one without relocating the battery to the trunk. Any suggestions?

Pablo94SC
07-05-2009, 07:09 PM
Running the low speed fan by grounding it can lead to problems if the high speed fan comes on. Instead you need to make sure the low speed fan goes open if the high speed fan comes on.

Exactly. Below is the best way to accomplish this.


Splice #14 wire in IRCM to #17 to disable low speed windings (fan) when high-speed windings (fan) activate. This should be done if High Speed relay works in the IRCM and Low Speed is being run off a manual or thermo-electric switch. CAUTION - Running both windings at the same time will quickly burn out the fan and possibly cause a fire hazard/wires melting/additional electrical problems.

Tim Groth
07-05-2009, 07:53 PM
A couple other things I've found that will seriously help the cooling on the 94/95 cars...


2. When my car was on the dyno, I noticed a significant amount of air was blowing up and out around the header panel and NOT through the cores. The early models have a small rubber-type dress plate that goes around the hood latch. It was there for a reason, and why it's not on the late model cars is beyond me!

Making a dress plate for that location should help force more air through the cores and not allow it to go up and over the upper radiator support. I'm in the process of making up a template and trying to find someone local who has the tools that can help me cut and shape this piece properly. Once I do and see how well they work, I'll offer these for sale for our cars.

4. Get a new radiator cap every year or two.



I have a 93 parts car, so I may look into pulling the piece you're referring too that goes around the hood latch. Good idea, thanks for bringing that to my attention.

I have the chin spoiler, that was actually my first thought on it running warmer than I would like. Again seems like it's where it should be however. Going to travel to Michigan Next weekend and just want to make sure the car is 100% before it makes the trip.

I have a new radiator cap to put on so I'll do that as well. Perhaps it will help a little as well.

Thanks again for all the suggestions.

-Tim

Tim Groth
07-19-2009, 03:35 PM
Just to update this thread for future folks with similar issues.

Come to find out the sending unit sensor on the side of the t-stat was the culprit of my heating woes (or so thought problems). Replaced the sensor with a known good unit and now car runs between OR of NORM.

Thanks everyone for the assistance in tracking down my problems.

-Tim

fturner
07-19-2009, 04:32 PM
You actually just proved how worthless the stock temperature gauge is in our cars. The only thing that sensor you replaced does is feed the gauge, and absolutely nothing else. So before when it went above M and now it is between O and R still means the temperature is the same, just at a different location on your gauge.

Fraser

Tim Groth
07-21-2009, 08:52 PM
You actually just proved how worthless the stock temperature gauge is in our cars. The only thing that sensor you replaced does is feed the gauge, and absolutely nothing else. So before when it went above M and now it is between O and R still means the temperature is the same, just at a different location on your gauge.

Fraser

Yup exsactly. I guess the piece of mind that atleast the dummy guage is reading in the right "general area" is way better than what I was dealing with.

-Tim

XxSlowpokexX
10-06-2009, 01:11 AM
Correct. The cooling fan has dual windings in it. One that causes the fan to spin slower, one to spin the fan faster. The high speed fan windings are not sufficient to get the fan spinning from a stop, thus the high speed will never come on without first energizing the low speed. Then when the high speed is called for, the low speed is shut off at the same time. Providing inertia for the high speed windings to take over.

Here is a link to a thread where I had dug up some info on the pusher fan:
http://www.sccoa.com/forums/showthread.php?t=17424&highlight=pusher+fan+turn
The original thread was here:
http://www.sccoa.com/forums/showthread.php?s=&threadid=23695

I think I now understand why my SC fan was never able to cool my mustang! Low mode was just not enough and well high mode......It must have burnt out the fan as it wasnt enough tto get it kicking on properly probably over working it causing my premature failure....ALl hail the mark VIII fan though!! It kicks butt...