Glen M. here and still having issues as in previous posts

I have had NO time to do any further troubleshooting so the wife has been dealing with the intermittent starting. Truck starts great first thing each and every morning. After that, it is a crap shoot. It does seem to work reliably only when engine is cold. Truck still has the SAME symptoms and I can find NO correlation from the radio working (it sometimes does and sometimes doesn't - whether started with key or by jumping relay posts)

I don't suspect the PATS per your last post we have only one (1) key for this truck and it runs fine regardless of method used to start and the dash lite works as it should.

I have not taken the starter off the motor as well as it works as it should and I don't have any reason to suspect the starter solenoid. It cranks fine when the relay is closed by key or jumping.

Both relays - new one and original bench test fine. I even took the relay from my truck and installed it with the same results.

Maybe taking another look at it after this long of a break will shed some light on it. My son, twintips_16 with a SCREW is also at a loss to explain.

ANY help you can provide would sure be appreciated.

Thanks
Glen

 

Have you had exhaust or transmission work done? A chaffed wire or two going to the DTR sensor could do this. So could a faulty ignition switch.

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JMC has a valid point. Don't know if you want to try to splice in a parallel wire for the output of the DTR to the starter motor relay.

 

How would I go about testing/troubleshooting this wire to see if it is bad?

 

Having problems uploading a picture at the moment, as soon as it works again, I'll upload the 99 starting system, this will show the wire from the DTR to the starter motor relay.

Easy route is to splice next to the existing wire.

 

Probe the #21 fuse. Should be 0v in in all positions except start and 12v in start. If you get these readings then disconnect the DTR sensor and probe the dark blue with orange striped wire. The results should be identical. If the readings are not identical then there is a short between the fuse and the DTR sensor. With the sensor still disconnected probe the tan with red striped wire. Should read 0v in all positions. Post back the results. BTW remove the 5 amp # 20 fuse and the radio should work.

EDIT: Is the transmission code a U or an E? Knowing this will make things easier to diagnose.

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Here is the 99 F-150 starting system, I think the 99 EXPY is the same ( don't have access to that DVD at the moment ).

 

The Expeditions do not have the CPP jumper.

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