Thank you Keith. Good job. I agree 100%. Diagnostic flow charts are not validated by the OEM. I was a technical trainer for Caterpillar for 7 years and the most frustrating thing was the errors in the diagnostic charts. I relied on system operations and developed my courses based on using only diagrams and knowing how the system works. I spoke with one of the technical writers about all the errors and he said they only write what the engineering teams tell them and that he was glad that I validated their diagnostic procedures. My conspiracy is OEM don't care because it is a huge profit margin to sell parts.
I can’t believe I’m just now seeing this video. Why didn’t I get a notification!? I can’t get enough of your videos Keith. Thanks for taking time out of your day to make this content.
Somehow managed to miss this video until now. Good job man. I have run into similar misinformation over the years and never trust flow charts. The only thing worse than not having information is having incorrect information.
My mom's Buick Century recently had an issue like this. The A/C clutch and indicator light would randomly turn on at times and sometimes cycle on and off by itself, even if the blower motor was in the off position. Tapping on the face of the HVAC control made the issue worse. I traced it to a cracked solder joint on the HVAC control board. When the circuit board loses the 12V signal, the HVAC control sends a signal to the PCM to command the A/C clutch on. Re-soldering the cracked joint resolved the problem.
Same here Keith. Didn't even get a notification for this video.. As you know I love your videos,They always teach me something and you are 100% right about flow charts. Since you know where I work I don't follow them all the time but must write them.... But we are talking about flow charts...ALL DATA Pinpoint test G is wrong.. G1 CHECK THE BLOWER MOTOR OPERATION NOTE: The IC monitors the blower motor operation through circuit 31S-FA26. When a blower motor fault is detected the IC stops sending the A/C request message to the PCM. Ignition ON. Select PANEL mode. Observe blower motor operation and select each blower motor speed. Does the blower motor operate in all selections and change speed in each? Yes GO to G2. No If the blower motor does not operate in any setting, GO to Pinpoint Test K. If the blower motor does not properly change speeds or shut OFF, GO to Pinpoint Test L. OEM flowchart G1 starts with blower motor operation if so. go to g2 G2Does the AC_SW IC PID read YES? Yes GO to G6. No GO to G3. since we know it only works on 1 and not in others you would pick G3 which wants you to check for an open ground,from switch to ground...n thats good next step to bypass switch and check all positions,if they do well switch is bad.. But you already knew this and didn't need a flowchart. Just saying lol All Data is wrong this time.lol
Nice video Keith! Over the years I’ve learned to stay away from flowcharts the pinpoint tests Imo are a waste of time in most cases, wiring diagrams and basic electrical understanding are far more helpful in diagnosing issues like this but I’m sure you know this already lol
I know your video is a few months old but it help me test some stuff on my transit. switch 1-3 fan speed does not work so gonna replace the resistor. Maybe easy fix. My issue is I been using fan speed 4 but had no AC. After watchin I went out and turned the switch to fan speed 1,2 then 3 and the AC clutch was engaged on all 3 but then the clutch disengages at speed 4. Now my head hurts...
I ran into this a few times on Nissans. You would swear up and down there is no way the RESISTOR could be bad but it's because the diagram leaves out what is inside the resistor. The feed back circuit is separate inside the resistor from the speed circuits.
when the blower motor resistor "low" speed doesn't have the load of the blower itself, the small amount of resistance would be low enough to pull the other pin low and make the instrument cluster happy/grounded and A/C on. was the blower actually running on the lowest setting?
Weird,the video is showing it has been posted 2 weeks ago although I haven’t received a notification until now. It also has 12 views,which I know it would’ve been possible if this was posted 2 weeks ago... Thanks for the video Keith! 👍
New Level Auto I already know this Keith. I'm getting ready to do your Empire in Northwest Indiana. Emissions and Drivability. Your a big inspiring on me.
Hi Keith Thank you. My clutch is not pulling in when the AC is on and the fan is on 1,2,3,4. If I ground the Red/Black wire with fan on 1,2,3, or 4. AC on, should the clutch kick in?
I don't understand how you manage get ac request grounding red and black wire if diagram showed red and black wire gets ground only on position 1. How can cluster get inputs from other speed positions , what grounds wire in other positions. Is that correct diagram
There is an underlying issue here. The aftermarket manuals, Alldata, Mitchel, ect. do not always get the complete or accurate info from the manufacturer. In this case the very first step is not correct in the pinpoint test. Pinpoint test G1 asks if the blower motor works in all positions (checking visually and physically for air flow change at the registers) if ok then go to test G2 if not ok go to a completely different pinpoint test to check the blower motor and it's controls. The second part of the misinformation from Alldata is the results of step G16. The following is quoted directly from Ford: "G16 CHECK IC BLOWER SWITCH INPUT NOTE: DTC C1779 sets when ground is present on circuit 31S-FA26 (BK/RD) to the IC . This step verifies that the IC input from the blower switch is OK. Ignition ON. With the engine off, place the blower motor switch in LOW. Enter the following diagnostic mode on the scan tool: Self-Test - IC . Does IC DTC C1779 set? Yes GO to G27. No GO to G17. " So it gets really aggravating using the aftermarket stuff from time to time as you can see step G10 is not listed in this wall of text and if you followed step G16 from this quote, it would lead to G27 not G28. However you would not have ended up at G16 using the Ford publication. I am a Ford tech at a Ford dealer and I also work at a local community college and we use Alldata, so I often compare the two and find many problems that would normally lead to bad results. Like I said it gets frustrating and you really have to keep your wits about you for sure. Great job with finding the inaccuracies and keep up the great work and videos........and get some sleep man!!!
I’ve been through this problem before it was the blower resistor. Ac request signal has a single wire from the 1st speed of the switch. Now first speed blower resistor must be good in order for circuit to be complete. I never follow a flow chart 😂😂
Kaysauto52 repair being that I have not had one in my hands it would not be fair of me to judge. I know Pico to be an awesome scope. I have only seen good things on the gmto so far. I assume you've see the simply diagnostics videos?
New Level Auto the thing that caught my eye with the mgto is how friendly user it is. Just by watching you guys my views is the Pico looks more detailed but the mgto looks very very user friendly(I could be way off). I'm stuck because both are costly. I guess more research before I decide. Thanks for your reply.
I believe it was mentioned below, but why does the diagram appear to show an a/c request should only happen in fan speed 1? Which is what exactly what it was doing! Did I see that wrong?
it gets ground through the blower motor resistor, without the high current "load" of the blower motor itself, the voltage on that wire would be pulled very near ground in any position back through the blower resistor... I guess one does need a multi year background in electronic for anything anymore......
Just determined it was my blower resistor not the switch. The switch is a simple contact switch that was in working order. But if your fan speed number one isn't working but turns the ac compressor on, it's the resistor. (Easier and cheaper to change also in my opinion)
I hate flow charts, just for that reason. I only use them for a reference occasionally, but I have been burned so many times in the past. I never charged my customer for the mistake I eventually fixed the problem and took the loss. Looking at the schematic how does the cluster know a/c request on speeds 2,3,4,5? I may have missed something 😕 thanks for sharing
Did the blower speed switch fix the concern? I have one in my bay that ac will not work on setting 4. Pid shows ac command on on settings 1-3 but not on 4. Ironically the blower motor resistor is bad on 1-3 lol
Just fixed a 2010 transit connect and had the same issue turned out to be a broken wire between the fan switch and the blower Resistor. So if you have one that has no low speed on the fan and the compressor only turns on on low speed check the wire.
I worked with some "Not it" Flow chart dudes rebuilding the whole car... I laughed. And they stated on the job longer than I did lol. Probably working someplace else now doing the same. That's some hack wiring !
going by the diagram suggests the blower motor resistor is bad.... the resistance through it would be low enough without the load of "blower motor" passing through to keep the black/white & black/red pulled low/close to ground and keep the "instrument cluster IC" happy. position two/pin 1 is only directly grounded by the blower motor switch in low speed. engineers trying to be tricky? :) was the "blower" itself actually running in "position one" low speed?
This post deserves to be "pinned"! The wiring diagram is CORRECT and uses a trick to determine if the blower motor is on. But something went wrong in between the switch, the wiring, and the resistor array. What is it, Keith? Thanks for the video, it's fun how a few wires and contacts can be so confusing :D
I'm sure the blower motor resistor has an "open" resistor or a terminal is corroded/melted for the low speed and blower isn't running there. they're quiet enough on low speed to be overlooked, I'm sure we just witnessed Keith miss diagnose one! it happens to everyone sometimes :) to check for blower function on low amp clamp on the black/white wire would tell you if the blower has current flow through it on low, alternately clamp onto the black/ground at the speed switch to check on all speeds or feel the vents to ensure air flow. in reality the flow chart is correct since the issue is a blower related (reduced outlet air flow chart), since the A/C does operate in one position the wrong flow chart is being used. it's a tricky one, now imagine diagnosing and repairing without schematics or flow charts at all. (insert much cussing and hours burnt here)
throttle bottle the blower resistor was certainly a fault as I had stated. The second part, the switch itself , was temperamental to even a tap , not witnessed in this video if I remember correctly. I don't think I was able to show the failure on camera. What I do know is both parts have been replaced and the vehicle is working beautifully. I am going to review all the above tonight to see if I did indeed miss something. I have no problem saying I made a mistake and I don't doubt you.
I just got into a new postion in dealership tech support for a large vehicle maker. I have access to engineering/factory information. Its still vague and gives you minimal info on circuit design and functionality. Its daily I tell techs to shot gun parts following flow charts. Its a very flawed system
Omg flow charts are so dam missleading i read them but then usually come up with my own test alot of time i just skip to the rear of flow chart and go from there
Thats why having the theory of operation is so important. Something that is almost impossible to attain here in Australia. Going of the wiring diagram alone would have led you to follow the flow chart and bammo. Instant come back.
Thank you Keith. Good job. I agree 100%. Diagnostic flow charts are not validated by the OEM. I was a technical trainer for Caterpillar for 7 years and the most frustrating thing was the errors in the diagnostic charts. I relied on system operations and developed my courses based on using only diagrams and knowing how the system works. I spoke with one of the technical writers about all the errors and he said they only write what the engineering teams tell them and that he was glad that I validated their diagnostic procedures. My conspiracy is OEM don't care because it is a huge profit margin to sell parts.
I can’t believe I’m just now seeing this video. Why didn’t I get a notification!? I can’t get enough of your videos Keith. Thanks for taking time out of your day to make this content.
Somehow managed to miss this video until now. Good job man. I have run into similar misinformation over the years and never trust flow charts. The only thing worse than not having information is having incorrect information.
Good to see your still around Keith. Great information and video once again. Gotta love flow charts lol.
Thanks Keith understanding how a system works is key to diagnosing
You are genius !!! you help me solve similar problem at my shop ... but in my case the problem was blower motor resistor !! Thanks !!
Good to see you back with another great informative vid. thanks
i wonder how many would have replaced the i.c . nice work thanks for taking the time making this .
My mom's Buick Century recently had an issue like this. The A/C clutch and indicator light would randomly turn on at times and sometimes cycle on and off by itself, even if the blower motor was in the off position. Tapping on the face of the HVAC control made the issue worse. I traced it to a cracked solder joint on the HVAC control board. When the circuit board loses the 12V signal, the HVAC control sends a signal to the PCM to command the A/C clutch on. Re-soldering the cracked joint resolved the problem.
great video Keith, no notification missed this video until now............. always enjoy your education
Same here. Glad I found it.
Same here Keith. Didn't even get a notification for this video..
As you know I love your videos,They always teach me something and you are 100% right about flow charts.
Since you know where I work I don't follow them all the time but must write them....
But we are talking about flow charts...ALL DATA Pinpoint test G is wrong..
G1 CHECK THE BLOWER MOTOR OPERATION
NOTE: The IC monitors the blower motor operation through circuit 31S-FA26. When a blower motor fault is detected the IC stops sending the A/C request message to the PCM.
Ignition ON.
Select PANEL mode.
Observe blower motor operation and select each blower motor speed.
Does the blower motor operate in all selections and change speed in each?
Yes GO to G2.
No If the blower motor does not operate in any setting, GO to Pinpoint Test K.
If the blower motor does not properly change speeds or shut OFF, GO to Pinpoint Test L.
OEM flowchart G1 starts with blower motor operation if so. go to g2
G2Does the AC_SW IC PID read YES?
Yes GO to G6.
No GO to G3.
since we know it only works on 1 and not in others you would pick G3
which wants you to check for an open ground,from switch to ground...n thats good
next step to bypass switch and check all positions,if they do well switch is bad..
But you already knew this and didn't need a flowchart. Just saying lol
All Data is wrong this time.lol
Nice video Keith! Over the years I’ve learned to stay away from flowcharts the pinpoint tests Imo are a waste of time in most cases, wiring diagrams and basic electrical understanding are far more helpful in diagnosing issues like this but I’m sure you know this already lol
Thanks again Keith! We really gotta watch them diagram and flow chart guys eh!
I know your video is a few months old but it help me test some stuff on my transit. switch 1-3 fan speed does not work so gonna replace the resistor. Maybe easy fix. My issue is I been using fan speed 4 but had no AC. After watchin I went out and turned the switch to fan speed 1,2 then 3 and the AC clutch was engaged on all 3 but then the clutch disengages at speed 4. Now my head hurts...
Have to take manufacturer flow charts with a grain of salt, excellent video Keith.
Thank YOU!!!!!! jesus this thing was kicking my ass all morning!!
Excellent Diagnosis !
I ran into this a few times on Nissans. You would swear up and down there is no way the RESISTOR could be bad but it's because the diagram leaves out what is inside the resistor. The feed back circuit is separate inside the resistor from the speed circuits.
when the blower motor resistor "low" speed doesn't have the load of the blower itself, the small amount of resistance would be low enough to pull the other pin low and make the instrument cluster happy/grounded and A/C on. was the blower actually running on the lowest setting?
Weird,the video is showing it has been posted 2 weeks ago although I haven’t received a notification until now. It also has 12 views,which I know it would’ve been possible if this was posted 2 weeks ago...
Thanks for the video Keith! 👍
Yes I mistakenly posted 2 weeks ago . Just releasing now
Well I can see how the 'flow chart' could lead into a clustered up mess. Thanks for posting Keith.
Nice to see you back.
Richard Gill thanks . Been waaaaaay too busy
New Level Auto I already know this Keith. I'm getting ready to do your Empire in Northwest Indiana. Emissions and Drivability. Your a big inspiring on me.
Oh yeah. Tell Rocco he Rocks with his Animation Stuff
SWEEEET VID 🚹, THANK YOU 👍
THANKS Keith .
Hi Keith Thank you. My clutch is not pulling in when the AC is on and the fan is on 1,2,3,4. If I ground the Red/Black wire with fan on 1,2,3, or 4. AC on, should the clutch kick in?
Question, could they have just unplugged the switch and checked it with an ohm meter?
Thank you!
I don't understand how you manage get ac request grounding red and black wire if diagram showed red and black wire gets ground only on position 1. How can cluster get inputs from other speed positions , what grounds wire in other positions. Is that correct diagram
There is an underlying issue here. The aftermarket manuals, Alldata, Mitchel, ect. do not always get the complete or accurate info from the manufacturer. In this case the very first step is not correct in the pinpoint test. Pinpoint test G1 asks if the blower motor works in all positions (checking visually and physically for air flow change at the registers) if ok then go to test G2 if not ok go to a completely different pinpoint test to check the blower motor and it's controls.
The second part of the misinformation from Alldata is the results of step G16. The following is quoted directly from Ford:
"G16 CHECK IC BLOWER SWITCH INPUT
NOTE: DTC C1779 sets when ground is present on circuit 31S-FA26 (BK/RD) to the IC . This step verifies that the IC input from the blower switch is OK.
Ignition ON.
With the engine off, place the blower motor switch in LOW.
Enter the following diagnostic mode on the scan tool: Self-Test - IC .
Does IC DTC C1779 set?
Yes GO to G27.
No GO to G17. "
So it gets really aggravating using the aftermarket stuff from time to time as you can see step G10 is not listed in this wall of text and if you followed step G16 from this quote, it would lead to G27 not G28. However you would not have ended up at G16 using the Ford publication.
I am a Ford tech at a Ford dealer and I also work at a local community college and we use Alldata, so I often compare the two and find many problems that would normally lead to bad results. Like I said it gets frustrating and you really have to keep your wits about you for sure. Great job with finding the inaccuracies and keep up the great work and videos........and get some sleep man!!!
Miss your video's my friend.
THANK U SIR
Nice video
I’ve been through this problem before it was the blower resistor. Ac request signal has a single wire from the 1st speed of the switch. Now first speed blower resistor must be good in order for circuit to be complete. I never follow a flow chart 😂😂
I was wondering what is your thoughts on the mgto scope vs pico. I'm in the market for a good scope I have little experience. I use the verus now
Kaysauto52 repair being that I have not had one in my hands it would not be fair of me to judge. I know Pico to be an awesome scope. I have only seen good things on the gmto so far. I assume you've see the simply diagnostics videos?
New Level Auto the thing that caught my eye with the mgto is how friendly user it is. Just by watching you guys my views is the Pico looks more detailed but the mgto looks very very user friendly(I could be way off). I'm stuck because both are costly. I guess more research before I decide. Thanks for your reply.
I believe it was mentioned below, but why does the diagram appear to show an a/c request should only happen in fan speed 1? Which is what exactly what it was doing! Did I see that wrong?
S & A Auto Repair no sir and that's what I meant by incorrect flow chart info
it gets ground through the blower motor resistor, without the high current "load" of the blower motor itself, the voltage on that wire would be pulled very near ground in any position back through the blower resistor... I guess one does need a multi year background in electronic for anything anymore......
Just determined it was my blower resistor not the switch. The switch is a simple contact switch that was in working order. But if your fan speed number one isn't working but turns the ac compressor on, it's the resistor. (Easier and cheaper to change also in my opinion)
Your version of Alldata is far superior to the one we have in the uk.
I hate flow charts, just for that reason. I only use them for a reference occasionally, but I have been burned so many times in the past. I never charged my customer for the mistake I eventually fixed the problem and took the loss. Looking at the schematic how does the cluster know a/c request on speeds 2,3,4,5? I may have missed something 😕 thanks for sharing
Did the blower speed switch fix the concern? I have one in my bay that ac will not work on setting 4. Pid shows ac command on on settings 1-3 but not on 4. Ironically the blower motor resistor is bad on 1-3 lol
Did you figure out what was wrong? I’m having this exact issue today as well.
Just fixed a 2010 transit connect and had the same issue turned out to be a broken wire between the fan switch and the blower Resistor. So if you have one that has no low speed on the fan and the compressor only turns on on low speed check the wire.
I worked with some "Not it" Flow chart dudes rebuilding the whole car... I laughed. And they stated on the job longer than I did lol. Probably working someplace else now doing the same. That's some hack wiring !
going by the diagram suggests the blower motor resistor is bad.... the resistance through it would be low enough without the load of "blower motor" passing through to keep the black/white & black/red pulled low/close to ground and keep the "instrument cluster IC" happy. position two/pin 1 is only directly grounded by the blower motor switch in low speed.
engineers trying to be tricky? :)
was the "blower" itself actually running in "position one" low speed?
This post deserves to be "pinned"! The wiring diagram is CORRECT and uses a trick to determine if the blower motor is on. But something went wrong in between the switch, the wiring, and the resistor array. What is it, Keith? Thanks for the video, it's fun how a few wires and contacts can be so confusing :D
I'm sure the blower motor resistor has an "open" resistor or a terminal is corroded/melted for the low speed and blower isn't running there. they're quiet enough on low speed to be overlooked, I'm sure we just witnessed Keith miss diagnose one! it happens to everyone sometimes :)
to check for blower function on low amp clamp on the black/white wire would tell you if the blower has current flow through it on low, alternately clamp onto the black/ground at the speed switch to check on all speeds or feel the vents to ensure air flow.
in reality the flow chart is correct since the issue is a blower related (reduced outlet air flow chart), since the A/C does operate in one position the wrong flow chart is being used. it's a tricky one, now imagine diagnosing and repairing without schematics or flow charts at all. (insert much cussing and hours burnt here)
throttle bottle the blower resistor was certainly a fault as I had stated. The second part, the switch itself , was temperamental to even a tap , not witnessed in this video if I remember correctly. I don't think I was able to show the failure on camera. What I do know is both parts have been replaced and the vehicle is working beautifully. I am going to review all the above tonight to see if I did indeed miss something. I have no problem saying I made a mistake and I don't doubt you.
wow
This is the switch for blower ac 1 sends signal to ac request the rest no problem
I just got into a new postion in dealership tech support for a large vehicle maker. I have access to engineering/factory information. Its still vague and gives you minimal info on circuit design and functionality. Its daily I tell techs to shot gun parts following flow charts. Its a very flawed system
lol, wires tore up/corroded :))
EDIT, I said this first, because many are known for wiring issues from salt corrosion out front.
Omg flow charts are so dam missleading i read them but then usually come up with my own test alot of time i just skip to the rear of flow chart and go from there
Even the wiring diagram was a bit off 😁 ground according to it would get at the IC only at position 1 😊 thanks Sir!
Thats why having the theory of operation is so important. Something that is almost impossible to attain here in Australia. Going of the wiring diagram alone would have led you to follow the flow chart and bammo. Instant come back.
+Kirk Abrahamson yes you are right, but the diagnostician here is one of the sharpest the world has!!!
armando nika . In total agreement there.
Put down the parts cannon
STEP G-54. Stop for 5 minutes of swearing and a little crying.
😂