Ignition switch wiring diagram

Tiny
DWB812
  • MECHANIC
  • 1989 FORD F-150
What is the trick to removing the covers on the upper steering column to access the internal ign switch components. When I turn the key the dash lights usually come on and then the starter does not engage when the key is rotated to the start position. The vehicle will start if the solenoid is jumped so I believe the problem is in the column. Can you help me out? I replaced the switch on the lower column and I still have no voltage at the solenoid from the switch. If I jump 12v to the small top terminal on the solenoid the starter spins so I suspect a problem between the ignition switch and the solenoid. I don't have a great deal of experience with Fords so I dont know the circuitry well enough to wing it without a wiring diagram. I hate to buy a book for this one repair. I'm trying to help out someone else. Any helpful tips you could throw my way would be appreciated.
Friday, August 27th, 2010 AT 5:28 PM

14 Replies

Tiny
SATURNTECH9
  • MECHANIC
  • 30,869 POSTS


https://www.2carpros.com/forum/automotive_pictures/416332_1989_ford_F150_starter_wire_diagram_5_1.jpg


Here's what were going to do with the truck in park i want you to test for power at the red and light blue wire going into and out of the neutral safety switch with the key in the start position it should have power to both of those wire's.Let's there.
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Wednesday, September 1st, 2010 AT 6:34 PM
Tiny
DWB812
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I probably should have also mentioned that it has a manual transmission if we are gonna talk about nuetral safety switches. Is it located at the clutch pedal, in the linkage, or somewhere entirely different on these trucks?
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Thursday, September 2nd, 2010 AT 11:35 AM
Tiny
DWB812
  • MECHANIC
  • 108 POSTS
I couldnt really read the wiring diagram but after some manipulation I was able to make out the clutch interlock switch and its location on the diagram. In short, I answered my own question. Will post when I have test results. Of course I will likely be able to troubleshoot this now. Thanks. I will let you know how it all works out or let you know if I have any more questions/trouble issues. By the way, did I say thnkyou? Really appreciate the help.
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Thursday, September 2nd, 2010 AT 11:44 AM
Tiny
SATURNTECH9
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Your welcome that's what were here for to help people with there car's. Let me know what you find and if you have anymore question's.
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Thursday, September 2nd, 2010 AT 11:52 AM
Tiny
DWB812
  • MECHANIC
  • 108 POSTS
Sorry about that. I never really saw the transmission designation initially. Must automatically list it as automatic if you dont change it huh? Well, I'm about to go out to the shop and check it out so I'll let you know. I'm sure I can run it down from here unless there is some Ford voodoo in the way I'm not aware of. Just curious, if I make a donation do you get it? Is there a way I can help you out. That subscription is not cheap!
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Thursday, September 2nd, 2010 AT 11:58 AM
Tiny
SATURNTECH9
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I think you are correct it does default to automatic if you don't change it. Yes if you want to make a donation it does help me out.I emailed you that wire diagram so hopefully you can view it better. Let me know what you come up with.
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Thursday, September 2nd, 2010 AT 12:08 PM
Tiny
DWB812
  • MECHANIC
  • 108 POSTS
Well, after further investigation I found a switch on the clutch linkage rod where it passes thru the firewall. It has a six pin connector with the following wiring. Pin 1 Red/Lt Blue, Pin 2 Red Lt Blue, Pin 3 and 4 green, pin 5 and 6 yellow/black. The numbering could be reversed. I'm just assuming they are like most other plugs and numbered from the left. There is 12v power at pins 3 and 6 on green and yellow/Blk (at least I think it's black, very faded) but no voltage on the red/lt bl wires even in the start position. There is no stand-alone light blue wire. I replaced the switch on the column (not the key tumbler assbly) so I know that is good and the key tumbler/rod is functioning to push the switch to the right position. At this point, I assume the switch is where the power comes from for the NSS red/Lt Blue circuit but I am unsure if this is the circuit to activate the starter solenoid or not. As always, your expertise is greatly appreciated.
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Thursday, September 2nd, 2010 AT 2:17 PM
Tiny
SATURNTECH9
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Alright you should have battery voltage to at least one red and light blue wire's with the key in the start position. Now at the ignition switch you replaced it look's like you should have two yellow wire's going to it they should both have battery voltage to them and there will be a red and light blue wire and that will have battery voltage in the start position. See what you find.
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Thursday, September 2nd, 2010 AT 4:35 PM
Tiny
DWB812
  • MECHANIC
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Well Louie,
I finally got some time to go back to this and all the voltages are there. I put in a momentary switch from 12v switched source to the solenoid/relay on the inner fender. I can get the engine to turn over but no fire. There is 12v power at the coil pack and the distributor except the outer two pins which are 4-6v in the run position. Didn't have an extra person to get readings in the start position. Can I get a diagram of the six wire neutral safety switch? I'd like to understand what is going on there electrically. I know it's a spring loaded slider contact but what are the yellow/purple wires and green wires (2 each) about? The red/blacks are also going thru there and are the final 2 of the 6. This is a six pin connector at the firewall above the gas pedal on the clutch rod. Any advice or help would be great and how to bypass the NSS would help too since this is just a field truck for farming to give field to field transportation. Let me know what you think.
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Sunday, September 19th, 2010 AT 4:11 PM
Tiny
SATURNTECH9
  • MECHANIC
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I posted a wire diagram for you on here you must have not seen it.I just emailed you a wire diagram for the starter it only show's the red and light blue wire's at the clutch switch. If all the wire's I had you check at the ignition switch check out then we have power coming into and going out of the switch to kick the starter over. Now we test at the clutch switch with the key in the start position you should have one of the red and light blue wire's have battery voltage with the clutch pushed in and the switch closed both the red and light blue wire's should have battery voltage. What the switch does is connect those two wire's when you push the clutch in. If that"s good then go to the starter relay inner right fender and with the clutch pushed in have someone turn the key to the start position. The red and and light blue wire to that should have battery voltage. Let's starter with getting the truck to turn over with the key and go from there. Let me know what you find.
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Monday, September 20th, 2010 AT 1:44 PM
Tiny
DWB812
  • MECHANIC
  • 108 POSTS
Hi Louie,

Well, I finally did what I should have done from the start. I used my trouble shooting and diagnostic skills to run down the entire ignition system. I found the Ignition module at the dist. Was getting proper voltage but not firing the dist. I replaced the module and presto. End of problem. Found out after I fixed it everyone suddenly remembers that it was/is a common problem with these vehicles. Gotta love those after-the-fact experts.
I thank you for all your help and am getting involved with the site. I am not a certified tech but I have a great deal of real world hands-on experience and knowledge of GM and Mopar vehicles and also DDEC. I hope I didnt drive you too crazy with my lack of confidence when it comes to Fords. Other than late 60s and early 70s Mustangs I have avoided them. Turns out they are just like everything else once you tear 'em open and start running things down. I did get the diagram but was confused that the other 4 wires were missing from the clutch interlock switch (I always call em an NSS) circuit. I "modified" the slider switch and made a 'Warning" decal for the dash. Like I said, it's just a field truck driven by farm boys.
I have a lot to learn about the site and it's features. I didnt ralize the OBDI & II code breakdowns where listed for example. The videos are a great tool to reference when working with less experienced members. Again, thanks for your time. I'm having the gal that does our books get together a donation to the site through my business. She says it's a tax thing that way. Hope to be able to learn more from reading your posts in the future.
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Monday, September 20th, 2010 AT 7:22 PM
Tiny
SATURNTECH9
  • MECHANIC
  • 30,869 POSTS
So it was the clutch switch causing the no starter action?Glad you got that figure out and the no spark as well. Also if your going to donate make sure you donate threw the user name you asked this question with so I get credit for helping you. Glad to hear you want to get involved with this site and give back and help others with there car problem's. Good luck to you with all your endeavor's. Also thank you so much in advance for your donation and thank you for using 2carpros.
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Monday, September 20th, 2010 AT 7:44 PM
Tiny
DWB812
  • MECHANIC
  • 108 POSTS
Will do saturntech9. Yep ignition module went out to cause the no run problem and clutch swith the no start. No problem once I slowed down and troubleshot the systems seperately. Thanks again louie.
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Tuesday, September 21st, 2010 AT 10:42 PM
Tiny
JAZZRUS
  • MEMBER
  • 1 POST
I have the same problem except the engine nor the starter stop when I turn the key switch off I have to disconnet the battery post. Then when I reconnect the battery the engine turn, starter keep turning.I`ve change the steering coloum it work for 3 month, started the sme problem. Will this info help?
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Saturday, December 1st, 2012 AT 9:55 PM

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