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SO...I know this topic has come up before and it seemed everyone has chased their tails but I found a consistent problem that isn't going to be easy for most to find. This all started a couple of years ago when I had a 2008 GT500 brought to me with an overheating problem. The weird thing was that the fan worked with A/C on and it wouldn't overheat but without A/C it would overheat...now I traced that down to a cold start up issue...if I went to lunch and came back, everything worked and the fan would come on as it should. What was happening was that with heat soak the connection expanded just enough to make contact and work but when it was stone cold it wouldn't make the connection. It is a known problem for the plug at the fan to melt but that wasn't the case here and today again, another '08 has the exact same issue but the owner didn't complain, I'm replacing the engine and found the same damage that I found on the GT500. This 2008 GT has the same problem and I haven't had a talk with the owner yet so I don't know if he even knows but this might be why I'm replacing the engine (It runs but badly, it's hurt)...although it may not have surfaced yet totally because you can still see the connection at the top of the block, on the GT500 they had started to move away as they melted the block.
SO...here it is....
This GT may still be working and hasn't failed yet like the GT500 I fixed but it will. This is the high speed and low speed fan circuit and both have gotten hot enough to melt the block under your fuse block under the hood.
Here is the old block I kept out of the GT500 we fixed a few years ago....These are not available from Ford so at that time I had to get one cut out of a car at a junkyard and re-pin everything.
Back then I knew these cars had issues with the fan but never had seen this issue...in the case of the GT500 it was fixed and seemed fine but 2 years later we had the same failure again. What this means is that Ford didn't use big enough wire or has other deficiencies that is causing these circuits to get too hot. After having repaired this previously and it came back, I am not even going to repair this one, I am going to remove these circuits from the block and install an aftermarket thermostat fan kit with relays to keep it separate from this block. That has worked since on the GT500 so it will be the go to fix on this one as well.
If you own one of these cars, do yourself a favor and separate the fuse block from these connections and inspect it....with the age of these cars now I am going to be that most if not all are showing signs of heat at this connection point. Since this is a GT, this problem isn't model specific since I have now seen the exact same failure on both a GT500 and GT. It IS possible it is year specific, I would need to examine other years to form that opinion for sure but I do now it is a problem on the 2008 models so far.
With 34k on Mine and Never Driven Too Much I'm Not Worried about Mine So Much But Just in Case Next Time I'm Fooling With it I Better Check! I Do Hear The Fans Run A Lot Here in Sunny California!
Thanks For The FYI!
Wonder If Due To Less Underhood Heat The V6 Wiring Blocks Might Hold Up Better!
Would Like To Hear About The Work Around and What it Involves When You Get It Squared Away!
With 34k on Mine and Never Driven Too Much I'm Not Worried about Mine So Much But Just in Case Next Time I'm Fooling With it I Better Check! I Do Hear The Fans Run A Lot Here in Sunny California!
Thanks For The FYI!
Wonder If Due To Less Underhood Heat The V6 Wiring Blocks Might Hold Up Better!
Would Like To Hear About The Work Around and What it Involves When You Get It Squared Away!
Well, the GT500 I worked on was a low mileage car...sub 50K....this GT is 154K...It's the heat in the wiring more than under hood heat.
That thread the car is a 2006...so that makes me think it's generational and not year specific...interesting that only one circuit was burned. Interesting fix.
Gotcha! Like I Said I Will Check Regardless. I Sometimes Get Good Idea's after a Bit of Riding Lawnmower Work as it Clears Out The Fog a Bit and Just Came in!
I'm Asking The Expert Here as It's an Idea But Not Execution. After Repairs When Needed, Could The Power Line For The Cooling Fans Be Hooked To a Heavy Duty Relay With a Direct But Fused or Circut Breaker Equipped Larger Wire Source And Hooked Up So The Fans Are Simply Triggered By Oem Setup and The Load Not Carried?? Hope I Explained / Proposed That Correctly! Maybe a Bit Oversimplified For Execution But Thought it Was Worth Asking About!
I haven't decided how I'm going to route this yet but the problem is that the connection there can't handle the load. We found the same problem on the Mustang SVO...Ford rated the connection at the plug for the alternator harness at 50 amps on those but they were equipped with 65 amp alternators so when a little dirt, corrosion or anything that would cause resistance happened at that plug connection, the wiring harness would melt at that point and was a fire hazard. I believe we may have a very similar problem here.
thanks for posting; this could be the answer to some of the mysterious fan problems, that seem to be fairly common
that connector looks way too small for 50 amps! does the full current go through there?
The 50 amp data is from the SVO example on the alternator harness...I found that in some Ford documentation years ago. As far as this circuit, I don't know yet exactly how much transmits through this particular connection. Give that the failure is at the connection I suspect it's more the connection than the wire but if the wire size was larger along with the connecting terminals I think it would go a long way to preventing this problem but there is no way to install larger terminals in the factory connection block.
What if You Repinned Two Clean Empty Spots Per Wire and Did a 1 Wire To Two Pins in and Out Two Pins To One Wire! Would That Work. Also To Keep Heat Down Between The Two Spread Them Out??
What if You Repinned Two Clean Empty Spots Per Wire and Did a 1 Wire To Two Pins in and Out Two Pins To One Wire! Would That Work. Also To Keep Heat Down Between The Two Spread Them Out??
KC
Well, here's the problem...the fuse panel is a sealed unit....
You can replace the entire fuse panel, I did that before on a '07 Shelby GT that had an intermittent starter relay connection where you couldn't get into the box to attempt to fix it.
Here is the bottom of the panel where it plugs into the wiring blocks, you can see the heat damage...the junction block is more of a sacrificial piece compared to this part, but this also shows the heat damage.
Well as Paul Harvey Would Say Now You Know The Rest of The Story!
I Was Not Visualizing The Connector Setup Correctly! My Bad! Once I Saw The Upper Pic I Remembered The Setup! Well The Memory is The Second Thing To Go! DOH!
Somewhat related question:
Is it normal that my fan seems to be on at all times,whether a/c is on or off?
It comes on a second or 2 after starting the engine even on completely cold start
The high speed fan should be on all the time with the A/C on, the low speed fan should only come on when the temperature threshold signal is sent to turn it on. I don't recall ever noticing one having the fan on at cold start, I don't currently have a running S197 here to check. Maybe someone else could chime in as to what their car is doing on cold start up.
Ouch, that is a nasty little bug. Just makes me wonder if Ford has fixed that in the newer versions or are we all waiting for this time bomb to go... Yikes!
Somewhat related question:
Is it normal that my fan seems to be on at all times,whether a/c is on or off?
It comes on a second or 2 after starting the engine even on completely cold start
with the A/C off (and also defrost off, because it uses the A/C) I believe: the low speed fan should come on at the low set-point, which I think is around 180-190 "standard setting" (not sure of the standard setting, but I know it is fairly common to reduce this to 170 when trying to keep the temps down) and the high-speed fan comes on a bit higher than that, maybe 200
so the short answer is NO, it should not be running immediately on cold startup (with the A/C and Defroster off)
Ouch, that is a nasty little bug. Just makes me wonder if Ford has fixed that in the newer versions or are we all waiting for this time bomb to go... Yikes!
Unfortunately, my gut feeling on this is that it started becoming a problem long enough down the road that the cars were no longer under warranty, so I fear that this is going to be an issue with a lot of them.
check your tuner: pretty sure the fan on settings is one of the user adjustable parameters
go in to the area where you load the tune; then go to "adjust parameters" or whatever it is called; look through the settings to see if you can find the fan on temps; I'm pretty sure it is in there. Then you can see if it is set to some crazy low number; and you can adjust to a higher number if you want. I am not sure what the factory settings are, but I think the low fan is around 190 and high fan around 210 or something like that
