Hi, new member here. 

I am diagnosing a no crank problem for the last few months. Turn the key and nada, no clickity click, nothin.

the first 19 times, i tapped the starter with a steel bar and it'd start then start normally for a week or so. . I dont think tapping actually had any effect now, i did think it was the starter. but starter works great. maybe a relay going bad and a few seconds to reset ?

the 20th time, i had to hotwire the starter solenoid and it fired right up, then it worked a few more times like normal.

now, after the 21st time,, i have to hotwire the solenoid each time i go to start.

I checked the voltage at the reverse/neutral switch on the starter. 3 wires on that plug.

Brn/grn stripe had 12 volts,

blk/wht had 10 volts which i dont understand that.

and purp/grn had 0 volts.

jump the Brn to Purp and the reverse lights come on.

Jump the Brn to Blk does nothing as far as starting or getting juice up to the starter.

Codes are P0122 , APPS, its been there for a long time. P1693, this one i havent seen this code before this problem. it is Trq converter solenoid.. ?

what do i troubleshoot next ?  the ignition switch ?

Power all the time at terminal 30, good.

Power at terminal 86 when key is turned to the start position, good.

Terminal 85 shows continuity to ground, good.

Terminal 87 is grounding through the starter motor solenoid. good.

Since you have been starting the engine by using a wire direct from the battery to the solenoid the starter motor is then assumed to be good. Using a jumper wire briefly connect terminal 30 and 87; the starter motor should engage.  If yes, then relay is bad.  If no, then there is a problem with wire/connectors between terminal 87 in the PDC and the starter solenoid.  

Except, i am not getting power to 86 with key on.    86  gives continuity to ground. 

I will double check again tomorrow if that is correct.. 

according to my diagram i made,    86 and 87  both had continuity to ground.

85 had neither voltage nor continuity.. 

I will see if i can check the ignition switch,  see if it is sending out 12 volts. 

connect #30 to #87 briefly to start. 

Ok,  I just tested the ignition switch.. all the wires seemed to be correct, except the YELLOW one,  when i turn the key to start it,  the yellow should give 12 volts i believe.

I am just about to remove the 3 security torx and look a little bit closer.    2nd gen ignition switch replacement.  hmm.  

3 minutes ago, John 98 Cummins said:

the yellow should give 12 volts i believe.

Yes, the yellow wire supplies 12V to terminal 86 of the starter relay when key turned to start position.  I think you found the problem in the ignition switch. 

yes, i was reading another thread on replacing it.   looks like the keyed cylinder may be ok.  and its the actual ignition assembly.  available at Rockauto.  

any tips on replacement ?     Odd though the way the problem started...  with tapping the starter to make it go.  doesnt make sense.   

I jumped 12 v to the yellow wire and #85   finally had 12 volts in the relay box,    So,  i better order the ignition before pulling the lock out.    Some of the videos i have watched,  show it is the key assembly that has a broken piece to it,  as opposed to the ignition assembly..   how do you rekey a new key assembly to my old key?

before i ordered an assembly, i checked for continuity on the switch where the yellow and red wire would go,  and i got continuity.    the yellow wire terminal did look a little corroded, so maybe it was just a bad connection at the yellow wire.. that's odd that it would be corroding.. i wonder what would cause that. 

 

I wrote this post almost 24 hours ago, but an ice storm nearby shut off the internet service, so I could not post.  Even though it appears that you have solved your problem, I am posting now anyway.

 

I would use a test light with an incandescent bulb for all my tests.  This test light will place a small electrical load on the circuit being tested and clearly show whether or not the circuit is working properly.  The tests are simple and reliable.  For part of the testing I would use a jumper wire.

 

For the following tests, use the wiring diagram to follow along for each test to help you understand the test and the test results.

 

Make sure the transmission is in "Park" and the park brake is set.  Ignition key "Off".

 

First test.  This test will check continuity between the starter relay terminal #87 and the starter solenoid.  Remove the starter relay.  Use a jumper wire and connect one end to terminal #87 of the relay base and the other end to the positive battery post.  The starter should operate.  If it doe not, then continuity between terminal #87 and the starter relay has been lost.

 

Second test.  This test will check continuity between the starter relay and ground via the transmission neutral safety switch.  Connect a test light clamp to the the positive battery post.  Touch the other end to the #85 terminal of the relay base.  The lamp should glow.  If the lamp does not glow, then have a helper move the transmission selector around during the test.  If the lamp occasionally glows, then the transmission linkage needs adjustment or the neutral safety switch needs be replaced.

 

Third test.  The test will check continuity between the battery, through Fuse #9 (30 amp), and terminal #30 in the relay base.  Use a jumper wire and connect one end to terminal #30 and the other end to terminal #87 in the relay base.  The starter should operate.  If it does not, then check the condition of the 30 amp fuse and wiring between terminal #30 and the battery.

 

Fourth and last test.  This test will check continuity between terminal #85 and the ignition switch "start" terminal.  Connect a test light clamp to the negative battery post.  Touch the other end to terminal #86 in the relay base.  Have a helper turn the ignition switch to the "start " position.  The test lamp should glow.  If it does not, then continuity has been lost between terminal #85 and the start terminal on the ignition switch.

 

Performing these tests should find the problem.

 

- John