1997 F150 starts with key in "on" position
#21
07-21-2018, 07:12 PM
The DTR would be the only concern as far as component/connectors there involving the start system.
There has to be a key start activated input voltage from the ignition switch sent on down and through the DTR (in P/N) then out to energize the 'starter relay' (solenoid) on the T/R (tan/red) wire there. Activating/energizing meaning the starter relay closing it internal contacts and 'then' sending current down via the black wire to the stater mounted solenoid itself which engages the starter drive and motor ops..
The only way for starter engagement in anything other than P/N or even with the key just in RUN (on) if there were an ignition switch issue, would be for the Tan/Red wire on the starter relay to be active, shorted to a hot etc. Even if the ignition was the issue, the DTR wouldn't allow current to flow to the starter relay 'unless' it was in P/N unless the DTR was misaligned, or faulted..
The input circuit from the the ignition switch on down into the DTR (key in start position) is on the DB/O (dark blue/ orange) wire. Anytime the key is cycled to Start, current should be present at/on the DB/O as well as the T/R if the DTR functional.
Unless the new starter relay had internal issues (no input control via the DTR and ignition supplied) , there wouldn't be any way for the battery current to flow from the starter relay lug on down to the starter mounted solenoid.
There has to be a key start activated input voltage from the ignition switch sent on down and through the DTR (in P/N) then out to energize the 'starter relay' (solenoid) on the T/R (tan/red) wire there. Activating/energizing meaning the starter relay closing it internal contacts and 'then' sending current down via the black wire to the stater mounted solenoid itself which engages the starter drive and motor ops..
The only way for starter engagement in anything other than P/N or even with the key just in RUN (on) if there were an ignition switch issue, would be for the Tan/Red wire on the starter relay to be active, shorted to a hot etc. Even if the ignition was the issue, the DTR wouldn't allow current to flow to the starter relay 'unless' it was in P/N unless the DTR was misaligned, or faulted..
The input circuit from the the ignition switch on down into the DTR (key in start position) is on the DB/O (dark blue/ orange) wire. Anytime the key is cycled to Start, current should be present at/on the DB/O as well as the T/R if the DTR functional.
Unless the new starter relay had internal issues (no input control via the DTR and ignition supplied) , there wouldn't be any way for the battery current to flow from the starter relay lug on down to the starter mounted solenoid.
#22
07-22-2018, 03:54 PM
Did anybody look inside the harness plug for the sensor on the trans to see if there was any sign of corrosion either in the harness plug or the pins on the range sensor itself?
If there was any kind of green colored "stuff" on the pins or plug , it might help answer some questions.
There is something that I find very puzzling and that is in the very first post, the wire , (Tan-Red), was off the relay and the starter operated normally with the key in the start position. Did I read this correctly?
If there was any kind of green colored "stuff" on the pins or plug , it might help answer some questions.
There is something that I find very puzzling and that is in the very first post, the wire , (Tan-Red), was off the relay and the starter operated normally with the key in the start position. Did I read this correctly?
#23
08-17-2018, 02:20 PM
Hello Hanky, I am back, been a couple of weeks...after "pulling his hair out" and rolling around on the ground until he feels like he's been beat with a ball bat, he thinks it is the Neutral Safety Switch...So he figured the NSS is getting ready to bite the dust. So we now have a new NSS. Here comes the next question...the new switch came with replacement plug...after scoping the situation out and everything (the plug that came with the new switch fits the old switch perfectly), the best he can tell is that all he has to do is put the put the new switch on, job done, and not worry about replacing the plug...he wants to know is there any reason why he should replace the plug?
#24
08-17-2018, 05:45 PM
If the plug fits and is the same as the old switch give it a shot.
There were corrosion problems with the older plugs , but I do not remember why if you had to change the plug other than to get a better fit and seal out moisture.
There is a definite procedure to align the mark on the switch with the mark on the trans with the shift lever in the neutral position.once this is done the arm can be installed back on to the shaft going into the trans.
We are changing the switch because "He thinks" that is the problem. Let's hope he is correct. We as much as possible usually like to prove that is the problem before replacing anything. Since circumstances are what they are , we'll go with replacing the switch. I will post a website where you can see the procedure for replacing that switch.
If you google - 1997Ford F150 neutral safety switch replace
Just have a cup of coffee and watch the video,
There were corrosion problems with the older plugs , but I do not remember why if you had to change the plug other than to get a better fit and seal out moisture.
There is a definite procedure to align the mark on the switch with the mark on the trans with the shift lever in the neutral position.once this is done the arm can be installed back on to the shaft going into the trans.
We are changing the switch because "He thinks" that is the problem. Let's hope he is correct. We as much as possible usually like to prove that is the problem before replacing anything. Since circumstances are what they are , we'll go with replacing the switch. I will post a website where you can see the procedure for replacing that switch.
If you google - 1997Ford F150 neutral safety switch replace
Just have a cup of coffee and watch the video,
Last edited by hanky; 08-17-2018 at 05:57 PM.
#25
08-19-2018, 12:20 AM
Hey Hanky, Let me tell you why my husband suspected the NSS...the first time we gave it the test (starting in P and N), that's what it did, started in P and N only. He decided later to test it again when he hit dead ends on what was going on with the truck...the truck started in ALL gears 
, the bad thing is it would do this on and off...sometimes it started like it was supposed to and then sometimes not. 
Sometimes he could start the thing 1/2 dozen times only in P and N, then all of a sudden the "s" wire stayed "hot" and the truck would start in ALL gears. That is why my husband thought NSS...w-w-w-e-e-e-l-l-l-l that ain't the problem. He replaced the NSS today and the danged thing still starts in all gears and the "s" terminal wire stays "hot" 
. I told him I think there is a short somewhere in the wiring, he's questioning if he should have put the new plug connector on. SOOOO now the truck has a new starter, new solenoid relay, new ignition switch, and new NSS...Would you please give us some ideas as to what else to look at? It would be greatly appreciated. Have a great day and God bless you.
, the bad thing is it would do this on and off...sometimes it started like it was supposed to and then sometimes not. Sometimes he could start the thing 1/2 dozen times only in P and N, then all of a sudden the "s" wire stayed "hot" and the truck would start in ALL gears. That is why my husband thought NSS...w-w-w-e-e-e-l-l-l-l that ain't the problem. He replaced the NSS today and the danged thing still starts in all gears and the "s" terminal wire stays "hot" . I told him I think there is a short somewhere in the wiring, he's questioning if he should have put the new plug connector on. SOOOO now the truck has a new starter, new solenoid relay, new ignition switch, and new NSS...Would you please give us some ideas as to what else to look at? It would be greatly appreciated. Have a great day and God bless you.
#26
08-19-2018, 04:50 AM
The purpose of the neutral safety switch is to prevent accidental starting in any position except P & N ..
This is what I would would do,
Carefully remove the plug from the switch.
Now with the switch not able to allow control , attempt to start the engine
If it makes any attempt to start , the only way power can get to that (Tan/Red) wire is through that plug and power has to be getting there from the Red/Black AND Dk.Blue-Orange wire and all that is happening behind the rubber cover between the connectors inside the harness plug. If you take a sharp pick and remove the rubber separator from the inside of the plug you might see corrosion or what is allowing power to get to that Tan/Red wire.
This is the logical thinking, however, if that Tan/Red wire has any opportunity to get power from some unknown alteration there is always that possibility.
Did you by any chance notice if the back up lights were coming on when they should not be ?
So you know how I arrived at the possible cause
The Red/Blk wire supplies power with the key on
The Dk -Blue/ Orange wire carries the signal (Start Position) from the ign sw to the switch on the trans
And the Tan-Red wire carries the signal(power) to the starter relay "S" terminal
Sorry for the extra trouble caused, you might have spotted the problem if you changed the plug at the time you replaced the switch.
Because the wires are so close inside the plug it makes this a possibility.
Looking into the harness plug with the high part of the plug on top, the pins are numbered from right to left on the top row, starting with pin #1, moving to the left ending with pin #6. Then going back to the second row right side starts with pin #7then on to 8,9,10, 11, & 12.
the red /Blk wire should be on pin # 9,, The Dk/Blue-Orange wire should be at pin # 10, Pin 11 goes to the back-up lights, Pin # 12 should be the Tan/Red wire .
Let's hope this takes care of the problem.
This is what I would would do,
Carefully remove the plug from the switch.
Now with the switch not able to allow control , attempt to start the engine
If it makes any attempt to start , the only way power can get to that (Tan/Red) wire is through that plug and power has to be getting there from the Red/Black AND Dk.Blue-Orange wire and all that is happening behind the rubber cover between the connectors inside the harness plug. If you take a sharp pick and remove the rubber separator from the inside of the plug you might see corrosion or what is allowing power to get to that Tan/Red wire.
This is the logical thinking, however, if that Tan/Red wire has any opportunity to get power from some unknown alteration there is always that possibility.
Did you by any chance notice if the back up lights were coming on when they should not be ?
So you know how I arrived at the possible cause
The Red/Blk wire supplies power with the key on
The Dk -Blue/ Orange wire carries the signal (Start Position) from the ign sw to the switch on the trans
And the Tan-Red wire carries the signal(power) to the starter relay "S" terminal
Sorry for the extra trouble caused, you might have spotted the problem if you changed the plug at the time you replaced the switch.
Because the wires are so close inside the plug it makes this a possibility.
Looking into the harness plug with the high part of the plug on top, the pins are numbered from right to left on the top row, starting with pin #1, moving to the left ending with pin #6. Then going back to the second row right side starts with pin #7then on to 8,9,10, 11, & 12.
the red /Blk wire should be on pin # 9,, The Dk/Blue-Orange wire should be at pin # 10, Pin 11 goes to the back-up lights, Pin # 12 should be the Tan/Red wire .
Let's hope this takes care of the problem.
Last edited by hanky; 08-19-2018 at 08:17 AM.
#27
08-19-2018, 11:15 AM
Thank you Hanky for your reply...and I have been searching everywhere trying to find a color code chart for the wire positions in the plug (my husband has not changed it out, because he knows once he takes the rubber grommet off he'll have a heck of a time determining which wire goes where) and you explained a 12 pin plug, would you happen to know the color codes for an 8 pin plug? The transmission is a 4R70W and all I can find is one for a 4EOD transmission...the plugs appear to be the same, however with a different transmission we doubt that the wiring would be the same. I have provided you a link for the instruction sheet that came with the new switch, I hope this will help you. http://www.oemautoparts.net/downloads/IS30.pdf . The truck does NOT have an electric transfer case. Your help is appreciated more than you know. Thank you!
#29
08-19-2018, 03:41 PM
Does your vehicle have this set-up?
Looking into the harness plug,
Pin 1-White/Pink (to start terminal on ig sw ) Pin 5-Black (Ground)
Pin 2-Black/Pink (Back up Lts) Pin 6- Grey/Red (EEC)
Pin 3- P/Orange (Vehicle Power 12 volts) Pin 7-Light Blue/Yellow (Trans range sensor)
Pin 4- Red/Lt Blue (To starter relay coil) Pin 8-Red/White (4X4 shift module)
If so , not hard to see possibility for problem between pins 3&4
We'll keep trying forever, if it doesn't take too long !
If this doesn't help , maybe you could provide the colors you have >
Looking into the harness plug,
Pin 1-White/Pink (to start terminal on ig sw ) Pin 5-Black (Ground)
Pin 2-Black/Pink (Back up Lts) Pin 6- Grey/Red (EEC)
Pin 3- P/Orange (Vehicle Power 12 volts) Pin 7-Light Blue/Yellow (Trans range sensor)
Pin 4- Red/Lt Blue (To starter relay coil) Pin 8-Red/White (4X4 shift module)
If so , not hard to see possibility for problem between pins 3&4
We'll keep trying forever, if it doesn't take too long !
If this doesn't help , maybe you could provide the colors you have >
#30
08-19-2018, 04:00 PM
Howdy Hanky, yes the production date is March 1996, GVW 6000 lbs., and Trans Code: U (U – Automatic 4R70W (F-150, F-250). Thank you for your help.
