My 02 Expedition with a 5.4L started out with an alternator charging intermittently problem. Engine running I rapped the side of the alt once thinking possibly a brush had hung up. Suddenly got a loud whining sound that seemed to come from somewhere on drivers side of engine compartment then the engine killed. Tried to start again, just got click from starter solenoid on firewall behind battery. Replaced Alt, old one did have issues, but after installing new one still only got solenoid click. Replaced starter, started right up, but starter would not disengage. Solenoid on starter heated up enough to let the smoke out. I assumed I had gotten a faulty starter, replaced, also replaced solenoind on the firewall, same problem! I swapped around a couple relays in the power distribution box, thinking that I possibly had a damaged set of contacts on one, stil same problem!
Anyone able to enlighten me on what I'm missing? Is there an additional starter relay that could be bad? I'd appreciate the advice. Thanks!

 

If you count up all the components in then starter system, it boggles the mind. Off the top of my head, I can think of these: Key switch, Generic electronic module, junction box/fuse box, transmission range sensor, starter motor relay, starter and battery.

Looking at the wiring diagram from the manual, I see that the transmission range sensor will interrupt the key switch between the fuse box and solenoid when the vehicle is out of park or neutral. That is where I would start. Disable the engine from starting, maybe disconnect all of the injectors or disconnect all of the coils. Then set brakes, chock wheels and anything you can think of to prevent vehicle from running away if it starts. Put it in 'R' and hook up the battery. If the starter runs, the problem must be in the wiring to the relay. If not, the problem is most likely in the key switch, or associated wiring.

My manual is for a '97. If you need locations on any of these wires, let me know and I'll give you what I've got.

 

The simpler test would be to just shift out of park or neutral when the starter gets stuck. If shifting out of park or neutral stops the starter then replace the ignition switch.

 

Except he's already burned up his new starter because it did not disengage. Unless he wants to put on a new starter every time he runs a test, better disconnect the battery.

 

Thank you both for the information. I'm gonna dig into it tomorrow and will start the isolation process til I get it figured out! I'll let ya know how it works out or doesn't I guess! If I need any info on the wiring I'll definitely holler. Thanks!

 

Ok finally got back to my starter prob on my 02 Expedition. Enlisted the help of a 20+ yr mechanic (even though he's a die hard Dodge man, and a relative!) he in turn got on the phone & started working all the certified Ford Techs he knows, & they all were scratching their heads raw as I had been doing . Long story short, in the very beginning of this whole mess I removed the wiring at the solenoid attached to the firewall in order to solder a new end on one of the main power cables, and you guessed it, I put it on the incorrect of the 2 posts on the solenoid!! Having a Dodge man find this prob was the least of the humiliation because I'M A LICENSED INDUSTRIAL ELECTRICIAN OF 18YRS!!! I DON'T TAKE SHORTCUTS DEALING WITH AC SYSTEMS BUT APPARENTLY FELT I COULD WITH DC!! I always number wires & their connection points or @ the least draw a diagram of what goes where. Thank you for the input & advice you gave this . I've got a 66 F250 4wheel w/a punched out to the limits 390, a 75 F150 4wheel w/a transplanted built up 460, & just bought a 76 F250 4wheel w/390 to put my snowplow on, so I'm either gonna be back with more questions, & hopefully some answers for other FOMOCO lovers in their times of frustrations.
Thanks!! Chad

 

Glad you found the problem!

Something you that might have helped diagnose the issue would have been to connect some sort of load in place of the starter -like a Harbor freight cheapie 12 volt heater.

Then you could 'crank' as much as you wanted and not hurt anything.

While you traced the problem with an active ckt.

 

I've got 10 more years than you do in the trade and I occasionally make a stupid mistake. Just yesterday the wife asked me to install batteries in the Christmas stuff she was putting up. Well there was this one dog that barks to Jingle Bells and wags it's tail; for the life of me I couldn't get it to work. So she says, "maybe you put the batteries in wrong", for which I looked at her and rolled my eyes while saying, "Oh please!" As soon as she left the room I quickly removed the battery cover and saw that one of the two batteries I installed was in backwards. I flipped it around and that stupid ungrateful little dog started barking to Jingle Bells just to squeal on me. Now a backwards AA battery might not seem like a horrendous crime, but it's still a mistake I should not have made.

 

Thanks all form the input when I needed it. Crashed this particular Expy on 1/15/12 and totalled it out. One question, what is the criteria to activate the air bags in a frontal collision? Mine was a 45mph+ inpact directly into the driver side front bumper horn. The impact was enough to buckle the frame upward into the driver compartment 6+ inches. That was both under the pedals and the driver seat, but yet my air bags never deployed!! Broke my back @ T12, but not sure the airbags would have changed that. Just a thought to ponder... BTW I'm in the market if there's anyone out there with advice or location of a good deal. Another Expy or a F250 Crew 4X4.