88_pacifica Posted August 9, 2017 Share Posted August 9, 2017 Vehicle- 2006 F150 5.4OK, I have searched and troubleshot, but I am not sure where to go from here. I believe that I have a deep electrical gremlin.Note: the wiring appears to be all intact and not messed with(factory wrapped), but I do know that there is always a possibility of an electrical break in wiring.In a nutshell: No 4wd active or any dash lights even showing a 4wd system(key on); no codes presentSo, I will key forward the ignition and no 4wd lights flash on startup or are present in any way. I continue to go ahead and start the truck and, while in park, foot on the brake pedal, attempt to shift to 4wd high. I get no lights, no audible shifting below on transfer case or any attempt to shift(4wd motor/solenoid), and therefore nothing happens. I have replaced the IWE solenoid, actuator/shift motor, and checked/replaced all relays and fuses pertaining to the 4wd section(I believe).So, I dug deeper. I did the vacuum test at the IWE solenoid itself and the IWE hubs ARE working. I tested by raising the vehicle, running vacuum direct to the hubs(hose tested straight manifold vacuum) and when vacuum is applied, both front wheels freewheel and then, once vacuum is removed, the CV's and front driveshaft turn together as they should. This eliminates the vacuum system at this point I believe.So, then I tested the vacuum directly at the IWE. I connected the bottom IWE solenoid manifold vacuum line, while leaving the top solenoid vacuum port loose and no vacuum is passing through the IWE to allow for 2wd. Now, this is a brand new IWE solenoid, so this leads me to believe that the electrical system is not opening the solenoid to allow the vacuum to pass through as it should.I have searched on here, the great wide world of the internet, and asked people more knowledgeable than I and nobody knows where to go from here. My supply of ford truck enthusiasts is nonexistent, so I am reaching out again for a lifeline.Does anybody have any ideas? Is there a simple check I'm not doing or area I am missing. With no electrical schematic, I am not even sure what is left on the circuit to check. Is there a way to test the actual shift knob switch to verify it is functional and, even if it failed, would there be no lights present on startup? Thanks in advance...Added: I did recently replace a brake caliper and the system needs bled(brake light is on) and I will be taking it somewhere to have that done(I've never had success bleeding ABS systems), but I do not believe that would cause the issue with the 4wd not lighting up or engaging. Quote Link to comment Share on other sites More sharing options...
fordtech1 Posted August 10, 2017 Share Posted August 10, 2017 I will bet you a beer you have a bad shift motor. If you pulled 4x4 codes you would have plate codes. Plates are position sensors inside the motor that tell the module where the motor is. Most of the time you can take a small hammer and tap on the shift motor while someone turns shift knob to different positions. Most of the time, if you get it to start working it will continue for a while. I have taken the cover off the motor and cleaned the contacts. In short, replace shift motor. Quote Link to comment Share on other sites More sharing options...
88_pacifica Posted August 10, 2017 Author Share Posted August 10, 2017 (edited) I will bet you a beer you have a bad shift motor. If you pulled 4x4 codes you would have plate codes. Plates are position sensors inside the motor that tell the module where the motor is. Most of the time you can take a small hammer and tap on the shift motor while someone turns shift knob to different positions. Most of the time, if you get it to start working it will continue for a while. I have taken the cover off the motor and cleaned the contacts. In short, replace shift motor. I actually did that as well. I have rebuilt many a window regulator/motor, so I checked this one out as well. I tore it apart and everything seemed to be in order. I did clean the contacts, brushes and then relubed the whole thing and it worked well(tested on a 12 volt source to be sure). However, I was not able to confirm if the electrical part of the motor was working(the part that I figure the PCM sees), even though the physical part of the motor worked fine. So.... I went ahead and bought a whole new shift motor and put that on ther instead. I figured I'd keep the old one for a spare to test once I get it all working. Unfortunately, in other words, it wasn't the motor since a brand new one is now on there. Edited August 10, 2017 by 88_pacifica Quote Link to comment Share on other sites More sharing options...
fordtech1 Posted August 10, 2017 Share Posted August 10, 2017 Without pulling codes it's hard. Did you disconnect the battery since replacing shift motor? Quote Link to comment Share on other sites More sharing options...
88_pacifica Posted August 10, 2017 Author Share Posted August 10, 2017 Without pulling codes it's hard. Did you disconnect the battery since replacing shift motor? oh man, unfortunately, I did. i don't have a 'true' ford OBD scanner, all I have is this https://www.mutualscrew.com/product/actron-cp9580a-autoscanner-plus-136986.cfm?source=froogle&gclid=EAIaIQobChMIsYTdwMnL1QIVVrbACh2HIgtFEAkYECABEgJ-5vD_BwE I did try and pull codes prior to the replacement and I got nothing except that it needed to be driven(Ford PCM factory 'learning process'). I don't know if that screwed me now, but I'm willing to take all advice you all might have. The part that baffles me is that I am seeing no voltage to the IWE solenoid at any time. I do not know where the signal for that originates(PCM, shift motor, shift knob/switch, etc). I am truly a Ford noob when it comes to these 4wd systems... Quote Link to comment Share on other sites More sharing options...
fordtech1 Posted August 10, 2017 Share Posted August 10, 2017 The iwe should have power on the pink/light blue with key on. The pcm grounds red wire to activate solenoid If not check fuse 11 and let me know what you find. Quote Link to comment Share on other sites More sharing options...
fordtech1 Posted August 10, 2017 Share Posted August 10, 2017 While you are checking, check fuses 11, 29, 30 and 111 Quote Link to comment Share on other sites More sharing options...
88_pacifica Posted August 10, 2017 Author Share Posted August 10, 2017 (edited) The iwe should have power on the pink/light blue with key on. The pcm grounds red wire to activate solenoid If not check fuse 11 and let me know what you find. This is likely where I am seeing the problem. I get no voltage at all to the IWE whether keyed on or not. While you are checking, check fuses 11, 29, 30 and 111 That was my thought as well. I checked the following fuses and relays(ohm'ed them out to be 100% sure): 11, 12, 29, 30, 111 and replaced R01 and R02(under hood, driver fender) Oh, and thanks for helping by the way.... This is a more complicated issue and most people just look and move on, so thanks again! Edited August 10, 2017 by 88_pacifica Quote Link to comment Share on other sites More sharing options...
88_pacifica Posted August 13, 2017 Author Share Posted August 13, 2017 (edited) I've never been a very good electrical guru, so I believe I'm just going to have to pony up and take it to get a full diagnostic since I don't know of any OBD2 scan tool able to pull the 4wd codes. Edited August 13, 2017 by 88_pacifica Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.