2k Expedition with 5.4 engine. Car started prior to replacing the starter switch under the steering column. Key switch turns and all lights on dash come on as normal. Turning key to start position, nothing happens. Left battery disconnected per instructions about air bag. Left disconnected over night. Now starter doesn't engage. Does replacing the starter switch do something to the security lockout ? Any ideas to try ? Battery is new and fully charged.

Greg

 

Are you referring to the factory PATS system? Then , no, it doesn't unless you managed to break something else.

 

Thanks. I suspect that the starter switch is not moving all the way into the "Start" position which springs back by the driver to the Run position after the engine starts. If this is the case then there is a mechanical problem in the key/steering column and not electrically related. To test this theory I'm going to disconnect the battery, remove the starter switch from the steering column and manually move the selector post on the starter switch. In theory this should work. After re-connecting the battery, insert the key and turn to the run position. There is a sensor around the key tumbler which reads the codes on the key. Next moving the switch post manually to the run position should bring up the dash lights. Moving the switch next to the start position should engage the starter motor. If this fails, then the next step is to check for 12 vdc on the Blk/org wiring on the starter motor relay.

Do any of the experts agree with this ?

 

There is an antenna wire/coil around the key lock so be careful of that. The PATS does not stop the starter from turning, so your issue is likely with the ignition switch, the DTR sensor (neutral safety), or the starter. If you place the key in the Run position and jump power to the coil of the starter relay under the hood, does the starter turn and the motor start?

 

I don't remember if this pertains to the older Expeditions, but on Ford vehicles around 2000, might be other years as well, if the ignition switch is wearing out it may not engage the starter in the starting position. You can try to push the key into the lock while holding it in the START position with force (not enough to break the key, you get the idea). This might be enough to make contact. If it does, you need a new ignition switch. If no luck on pushing the key into the lock, you can try to move the gear shift lever through the gears while holding the key in START (apply the brakes in case the engine starts in a gear). This might help if there's an issue with the DTR switch on the transmission.

Regarding the PATS, look at the THEFT light while you turn the key to RUN and then START, if it's flashing rapidly it means it doesn't recognize the key and is inhibiting start. On the 1st gen, this would only cut off fuel to the engine, the starter would still engage and crank the engine. It was only in later models that PATS disabled the starter.

 

Interesting about the PATS on the later cars. Yes alloro I have removed the ignition/switch from the column, put the key in the mechanical switch and turned to the run position, moved the pin on the starter switch and the car started.
The main problem is fixing an intermittent starting problem. The first step was to replace the starter switch and follow the problem either downline or upline. The intermittent starting problem is that the starter solenoid sometimes does not fully engage with the flywheel. Shoving the shift lever forcefully into park or neutral the starter engages correctly. Other times it makes a loud noise as hits the flywheel and not the ring gear to start the motor. Yes, mechanics would say this is a starter motor issue and I'd agree but after replacing three starter motors already, the last one purchased from the dealer, it time to start looking else where for the problem. I suspect this is an electrical issue and when the solenoid is not getting the correct voltage, it doesn't fully engage. The next downline item prior to the starter relay (mounted to the firewall near the battery) is the Neutral safety switch.
Would the experts agree with this train of thought ?

 

If shoving the gear shift lever into Park engages the starter, that indicates either that the DTR switch (neutral switch) is either misaligned or bad. I had this issue on my 05 Expedition, which has the same DTR switch as 1st gen Expy. I removed the DTR switch and it was impossible to rotate it by hand. I checked the DTR switch on a friends Expy, which rotated easily by hand. Installed a new switch and no more problems starting. I disassembled the switch to check what had gone wrong, and it turns out the switch itself was fine, but the O-rings on the nylon ring that engages with the transmission had swollen up and was binding the switch so it couldn't move.

 

Yes, definitely an issue with the DTR sensor, it's alignment, or the shift linkage.

 

Question, have you done the shift linkage triangle plate 2 torx bolt tightening repair yet?

 

Yes I have re-tightened thee torques bolts on the shifter column. As soon as the rain lets up today, I will check the train linkage on the transmission.

 

In tracing out the battery ground cable and jumping the car directly from the starter relay, I found that I need to replace the starter relay on the firewall.

My thought was if I bypass the neutral safety switch and shorted directly across the starter relay, I could get the car to starter correctly and the bendix gear would have the correct voltage applied. That was not the case and shorting across the starter relay produced the same whinning sound indicating the starter gear was hitting the back of the flywheel. I believe that this points to either a grounding issue or downline from the neutral safety switch. Then I found a problem.

The housing is cracked on one of the battery lugs of the starter relay. Placing an order tonight for both a neutral safety switch and a new starter relay. I've also been told by a ford mechanic that the battery ground to the chassie goes bad, resulting in all kinds of weird electrical issues. Also plan to replace the battery ground cable. I'll keep this post updated.

 

Replaced broken solenoid on the firewall. Cleaned up the slip-on connection (control wire) from the neutral safety switch (according to the schematic). I was originally getting 4.5 VDC at this connector. I knew it should be around battery voltage or close to it. Found corrosion in the connector and cleaned out with sand paper. Re-measured and got 12 VDC which I expected. Put the cleaned up connector back on the solenoid but didn't make a difference. Still same sound as the bendix hits the flywheel. Currently removing starter to inspect flywheel along with starter connections.
It was noted that a mechanic had a test light with a built in volt meter measured the voltage drop at the starter when starting the engine. Various voltage drops where observed when starting the engine with the car on a lift. The lowest was 9.8 volts and this was on a fresh battery. Would the forum experts recommend changing the positive wire from the fire-wall solenoid to the starter motor as being the next suspect ?

 

That is an acceptable volt reading when cranking as long you get the same reading at both the starter terminal and the battery terminal +/- 0.5 volt.