My friend has a 2000 F150 that he parked and it would not restart or turnover.
I jumped the solenoid in the engine compartment by applying 12 volts to the little ignition wire (brown with brown/reddish stripe) running to the solenoid with the key in the run position. It then will start and run fine.
I have checked fuses(they are all good) and when I attempt to start the vehicle I can hear a relay click inside the vehicle and also hear a relay click in the main fuse panel inside the engine compartment.So I assume they are good.
So my problem is where I should look next since I haven't been able to find to where it goes under the dash yet. I did follow the wire from the engine compartment and it looks like it goes near the transmission somewhere.
Not sure if others had same problem.

 

Not sure why you think a clicking relay is good. Usually a relay that is clicking is the coil energizing and de-energizing, which could be power to the coil, or the coil in the relay itself.

Have you tried to start the truck in Neutral ?

The wire goes to the transmission, and is connected to the DTR ( Digital Transmission Range ) Sensor.

You need to meter the wire leaving the DTR to the start motor relay to make sure it is good. The input to the DTR is the Dark Blue w/ Orange stripe wire. This should have + DC V on it when the key is in the start position ( make sure to secure the truck when testing this, parking brake chock the wheels, etc ).

 

Tried neutral and no change nothing.

With the relay clicking I meant to mean that I when I turn the ignition to try and start it that I hear a single click meaning it is energized plus I swapped them with others and still no change.

Will try your suggestions and check for power to the point by the transmission.That would also explain why I have not been able to find the brown wire going back into the ignition under the dash.

 

The Tan w/ Red stripe wire is not in the ign ( as you found out already ), as well as don't expect the Dark Blue w/ Orange ( not sure if it changes from the cab fuse panel, fuse #21 ).

That is another place to check, for power on Fuse #21 when the key in the the start position. This is in the CJB ( aka Central Junction Box / Cab fuse panel ).

 

When you hear a "click" from a relay, it means it is reacting to a voltage impulse to it. If the starter turns and the engine starts when you apply power to the starter solenoid it means they are both fine and the "run" circuit is also ok.

So, is power getting from the starter relay to the solenoid? It would seem that this is where the problem is. I see a couple of fuse links and some connections I'd investigate. And, of course, the relay contacts themselves could be defective.

- Jack

 

Went and checked DTR and the Dark Blue w/ Orange stripe wire had 12 volts and was able to jump the brown with red stripe wire to the solenoid and it started so at least i know the wire is good.

I went back to the fuse box and retested fuse #21 as you stated. I used a voltmeter and in the run position I am only getting 4.5 volts. If i try to start the car then it goes to 12volts. Something definitely not right. Fuse #20 is also showing 4.5.

 

I am confused here.

Fuse #21 as well as the Dark Blue w/ Orange stripe wire are the same on the fused side.

You got +12 V DC at the DTR ( I assume when the key is in the run position ) but at the fuse you got 4.5 V DC and +12 V DC when the key was in the start position ?

The Dark Blue w/ Orange stripe wire and Fuse #21 are one in the same, if you had a problem it should be with the wire not the fuse ( wire cannot make voltage ).

How are you testing when you get 4.5 volts ?

When you jumper the Dark Blue w/ Orange stripe to the Tan w/ Red stripe wires, that is with the key in the start position ?

 

I disconnected the plug at the DTR and with the key in the run position I had +12volts. I jumped it to the brown with red stripe and the truck started. Put the plug back into the DTR and the truck would not start.

Then checked fuse #21 at the fuse and it was reading 4.5 volts with mutlimeter .Negative ground to chassis and positive to the fuse. If i tried starting the truck the voltage would then go to 12 volts at the fuse.

If the rain stops I will retest it again in case I screwed something up. I will also double check to make sure I had the correct color coding wire by the dtr.

I double checked the fuses and it seems like fuse 20 might power fuse 21. If i yank #20 then i get no power at 21. Odd indeed

 

OK. I doubled checked it . You were right in that by the DTR I had 12volts at the blue/pink (teach me not to use a flashlight under the car) which was the wrong wire. I rechecked at the blue/orange and i had 4.5volts the same as at the fuse.

 

Hopefully this will be the last time. By looking at the schematics I thought it might end up being the DTR aka Neutral safety switch. A little bit of adjusting and I was able to start the car up with no problems anymore.

My question then is with fuse #20 and #21. I metered it out now and it only shows 12 volts when it is cranking. The rest of the time whether running or not it shows 0 volts. Am i correct?

 

OK, the DTR was not closing the contacts to being off a little bit. Good on you for finding it.

I know Fuse #21 for the Starting system should only have 12 V when the key is in the start position, any other time it should be 0 ( no need to apply power to the starter motor relay with the engine running ).

I'd have to check what Fuse #20 was to tell you if it is the same case, but from your testing I would say yes, it is a hot in start position fuse.

 

Thank you for all your help as it would of taken me a long time to figure this mess out.

 

So, if the DTR was at fault, what the heck was the "relay click" he heard? Seems to me the relay would not have been getting a signal at all.

- Jack

 

The relay click inside the truck had nothing to do with the starter motor relay on the firewall ( starter motor relay location for 97-03 MY ).

The 04-08 MY the starter motor relay is in the fuse panel in the cab.

Maybe it was the fuel pump cycling ? that makes a click / hum noise when the key is turned to the run position ( until pressure is built up, think it is 3 key cycles until it releases the pressure ). Just a SWAG.

 

Thanks, my friend. I was just curious what other things "click".

- Jack