Test for ignition switch and/or neutral safety switch?

[Brian VT]

I guess this is my next step. Looks a lot easier to work on than the tilt wheel version.

Motorcraft Ignition Switch SW-2472 (none in stock near here so I'll be buying an aftermarket one).​

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[Brian VT]

New ignition switch didn't change anything. :-(
My backup lights work when I put it in reverse so I'm thinking that the neutral safety switch is ok? (I think I replaced it within the last 2 years).
So...what now? I guess I need to test the output of the ignition switch? Any advice on how to do that?
And then check the continuity of the wire from the ignition switch to the solenoid? (if I have power leaving the ignition switch)

 

[Brian VT]

Found this but not sure how to use it. I guess I try to pull the wires and swith down where I can work with them and then what?

 

[Rdnck84_03]

Use a test light and back probe pin 32 while pushing the switch to the start position.

James

 

[IDIBRONCO]

If you do have power for a start wire at the column and you don't at the solenoid (which you know that you don't) then you have found you problem. That wire is broken somewhere along it's route. Then you can find and fix that break, run a new wire to the solenoid to bypass the old wire almost entirely, or you can add a push button for the starter.

 

[Rdnck84_03]

Something else to check if you haven't already. I saw it mentioned recently but I don't remember if it was in one of your threads.

Your truck will have the wiring under the dash for a clutch safety switch, it should have a dummy plug that jumpers the starter wire.

May pull it apart and make sure it's not corroded, and could test for signal from the switch to that point (should be the first connection point after the switch).

Then put the jumper back in and backprobe for voltage from the switch to the neutral safety switch. If you have voltage to it, then test it on the other side.

If you have voltage on both sides of the neutral switch then it is the wire from there to the solenoid. If you only have voltage on 1 side the the neutral safety switch is bad.

If you don't have voltage on either side then the wire between the neutral switch and the clutch jumper is bad.

James

 

[Brian VT]

I didn't know I had the clutch safety switch. Thank you for that and the other tips.
I may go back at it on Sunday.

 

[Rdnck84_03]

You don't have the switch but the wiring is there for it, it just comes from the factory with a jumper installed in it.

James

 

[XOLATEM]

Found this but not sure how to use it.

The other guys have you steered in the right direction...and better than I could have...
...but I just wanted to add one thing...on that wiring diagram picture...I believe that the two 'proof' connections...this is just a guess...are your neutral and park position safety circuit...

...and...the switch should be tested with the wires disconnected from the harness...just to be sure...and look for continuity with an ohm meter with the trans selector in 'N'...and then in 'P'...

good luck on it...you have a lot of good help...

 

[Brian VT]

I'm back into this today.
The column switch is really tough to get in there and test so I'm trying to rule out everything else 1st.

I confirmed continuity of the wire that's between the solenoid and the firewall.
So the problem is back of there.
Let's go back to the neutral safety switch (on my C6 tranny).

When in park or neutral, testing at the pins in the disconnected plug near the tranny, should there be continuity between the two Red/Light Blue wires that go to the switch on the steering column?

When in park or neutral, testing at the holes in the disconnected plug near the tranny, should there be continuity between the two Red/Light Blue wires that go to the switch on the tranny?

 

[IDIBRONCO]

The column switch is really tough to get in there and test so I'm trying to rule out everything else 1st.

Which is smart. For testing the column mounted switch, it may be easier to remove the plastic piece that runs underneath the steering column and then drop the column down. It only takes removing 4 bolts, that are completely obvious after removing that plastic piece, to drop the column down. Youi DO want to hold onto the column while you remove the last bolt. It will drop right away and it may be onto you.

 

[Brian VT]

Thank you for the reply.
I have the column down as I replaced the switch last weekend.
It's really tough to get in there to test though (with my big hands and 2 multimeter probes).
So I got frustrated and decided to try to eliminate everything on both sides of the switch.
I have confirmed that the wire from the solenoid to the cab has continuity.
So now I'm trying to confirm if the neutral safety switch, and the wiring to the column, are good.
If those are good then it must be under the dash. (ignition switch or clutch switch that I haven't found yet)

 

[Brian VT]

both are simple pass-throughs for two seperate circuits...

One...neutral safety and park position for starting...

Two...reverse lights...

If you want to test it...disconnected from the harness....put the lever in reverse and test for continuity with an ohm meter...there is your pass-through for reverse lights...

Next...put the lever in park and test the other wires for continuity and repeat for neutral...there is your park and neutral safety circuit...

Batteries are disconnected, fyi.

I tested for continuity between the 2 red/lt.blue wires going from the column to the the neutral safety switch on the tranny.
I was testing by touching the pins in the connector for the neutral safety switch that I had disconnected.
Key on. Neutral, no continuity. Park, nope. Key in start position, Nope and Nope.
I believe I should have had continuity during at least 2 of these key/shifter positions? If not all 4? (I would be happy with 1 at this point, lol)
I also believe by doing this I am bypassing the neutral safety switch, so it rules that out as the problem, correct?

I tested for continuity on the other 2 pins when in reverse. They have continuity. So it seems that my column switch is adjusted properly? Because they don't have continuity when in Park or Neutral.

I tested the switch on the column for continuity from #37 (battery). When I turn the key to start, #32 (start) has continuity as does #16 (ignition).

I'm stumped. Bad wires from the column switch going to the tranny switch? Bad plug to the tranny switch plug (where I was testing from it's pins)?

 

[Brian VT]

Is this what the factory used instead of my clutch safety switch? (since I have a C6 auto.)
I was expecting to see red/blue (starter) wires in addition to green wires (cruise control).
If this isn't it then I can't find my (factory jumped) clutch safety switch.

 

[XOLATEM]

I can sense that you are getting pretty frustrated and probably should step away from this thing and give yourself time to ponder....

I have been there....it has been a long time...but I remember an instance once where I was stumped on something...I thought that I had tried every possible method to get something working and despite my best efforts at the time...nothing was fixing the problem...

It was frustration beyond belief...I was seriously questioning myself and my ability to do my job....

I had to step away...next morning...I had the answer...and I felt like a total dumb a$$...but I got it fixed...and I learned that I can only fix something if I have enough info on what it needs to work and if I am in the right frame of mind to put it all together and find the missing link.

What kind of tool are you using to test for continuity..?

If it is just a test light...it is going to be a lot harder to sort it all out...

I would invest in a Power Probe...

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You don't necessarily need the latest model....older versions will work for you, I figure...ebay and amazon...

The second thing you could use is a comprehensive wiring diagram...that would give you the whole story on your circuitry..

I probably did a less-than-sufficient job of explaining my method of testing the NSS...I have had very few of them go bad over the years...and I just took them for granted and never really thought about whether they are a path for the positive 12V or merely a ground path..

...but after thinking about Ford's tendency to not want to give the vehicle any reason to catch fire...I don't have a wiring diagram handy...but I believe that the switch (NSS) is merely a ground path to allow the starter relay to activate...just a guess...

If you could get ahold of a diagram that shows the whole start circuitry...you might get a handle on this thing...

As far as the wiring jumper you have found...if you don't have cruise control...I would guess that those green wires were to the brake switch for that option...

Where my truck is and where I am now...I am not able to check the color of the wires to my clutch switch...but when I am...I will let you know...