I just picked up a new to me 2005 F250 4x4 with manual trans.

Problem is when I turn key to start, I can hear a relay clicking but nothing else happens. I can turn the key to "ON" and use the jumper wire under the hood, touch it to positive and it starts right up.

Whoever was "working" on this previously did some rewriting of the clutch safety switch. I probed it and don't have any power to the switch. I'm assuming this may be my problem.

Which fuse carries power to the safety switch? Everything looks good in the fuse panels. If this truck started with the key it would really be nice...

Thanks in advance

 

How about a wiring schematic of the safety switch?

 

I'll see if I can get you the 06 diagram if that
will work for you.

Sean

 

Thank you so much.

 

Was there ever a remote start or alarm in the truck? If there was sometimes there is a relay inline to kill the starter. And if it's a standard make sure there is not a scotch lock crossing the two clutch wires they can cut right thru the wires

 

Also check the Starter Motor Solenoid Relay Switch. Failure symptoms are similar to what you describe.

 

Made some progress. Narrowed it down to the starter relay. Tested relay and it is good. With key on I have power to terminal 30 of the relay. With key turned to start, I get power to terminal 86 of relay. If I jump terminals 30 with 87 with a wire, starter engages. It seems I don't have a ground to terminal 85 of the relay, and therefore cannot make a complete circuit to engage the relay.

Does the clutch safety switch provide ground? I have been trying to jump various combinations of the four wires going to the clutch switch with no success.

I'd really like to fix it properly rather than have a redneck push button switch from a lawnmower on the dash...

 

Sorry about being so slow in getting these up for you.
Here you go.

 

Thank you so much!

This helps tremendously!

 

Your Very Welcome.
Please be sure to let us know how this comes out.
I am back home and have better access to the diagrams.

 

It seems the connection in questions terminates to ground via the PCM. I pulled the PCM and found a buggered up pin. I straightened it thinking it might be the solution but it did not make any difference.

Is there a way to test if the PCM is bad? Maybe I need to get that IDS subscription now for sure.

Here's a pic of the pin in question that was bent.

Could the previous owner installed a PCM for an automatic trans? Would it make any difference?

 

I "think" it may be the same one in both cases with a programming change.
But it might also be that there is a auto and manual PCM. You could look up
the part numbers at Official Ford Parts Site | Buy Motorcraft & OEM Ford Parts Online | FordParts.com
Then you would know.

BTW : Most of the controls are done by sinking the current (controlling the ground)

NOTE : U think it might be better to remove the CJB from the truck so that
you don't have any power going into the wrong places and let any smoke oit.

Now for some thoughts : If you back probe C270f pin #6 & #9 #6
should be hot in start and gets power from F2.31. Pin #9 should go
to ground when you turn key to start. Then if you unplug C270f and
check resistance on pin #6 & #9 you should see only a few ohms
with a meter on low range. Then take 2 jumpers from a 12V battery
(a small one would be better) place meter on pin 2 of C270g and the
other on a jumper blade at F2.113. You then apply 12V to pin #6 & #9 of
C270f. You should see the resistance drop to near 0 for the fuse to pin
#2 of C270g

In stepping back and looking at this again. Look at C2163 in the CJB
That should be the starter relay.

 

C270f pin #9 is definitely not going to ground when I turn the key. Gotta figure out why...

I'm still questioning why they cut clutch interlock wiring. Possibly just to bypass switch, I suppose.

Took center harness off PCM to inspect. Everything looks intact, no loose wires.

Possibly PCM malfunction? Could I reprogram the PCM via IDS or would it not make any difference? I have a renewal coming this week, they just have to generate a P.O. to get it done for me.

 

I think I would start with a meter and look at the wires
to see if there is a broken pathway from point A to B.

Sean

 

Do you happen to have a pinout of the PCM connectors?