2003 lincoln towncar no crank no start

After watching your video How to troubleshoot a starting system (bad ignition switch) - Dodge Neon I have a Question: I recently bought a 2003 Lincoln Towncar 69k miles garage kept. nothing was wrong the first 1200 miles... then one day no crank no start last week I changed out my ignition switch thinking that was the problem ...(electrical side) under dash on column only $20 it was not the problem . I also can crawl under car and jump the starter off the positive post of starter to start post so i know starter battery and solenoid work that is why i changed ignition switch. ( I also removed starter and had it bench tested at the auto parts store (works fine only 69k miles on it) and then reinstalled) when I pull out the starter relay under the hood in fuse box and put a test light in terminals after checking ground and making sure light works ( it did) There is no power in any of the 4 pins of the relay terminal and when in run and crank position there is no power in any of the 4 pins in the terminal . Does this leave me with a PCM problem because that controls neutral safety and starter signal? I have checked all fuses and all working . The dash cluster warning lights also do not light up when key is turned to run and there is no security light flashing in cluster. However the flashing light for security does shut off after 3 seconds like it is supposed to on the dash when key is in run right before crank position. please help me confirm it may be pcm , Thanks Rich
REPLY

In the Battery Junction Box, Check Fuse 101. It is a 50 amp fuse.

what if the power feed coming into the ignition switch has no power? but i do have power coming to the 50 amp fuse in fuse block . what does this tell me? anyone? thanks

That would suggest a blown fuse.



Or, an open in the yellow wire.

thanks , i am going to check for an open in the yellow line because the fuse is good #101 50 amp could you post the other diagrams it said 2 of 3 different diagrams

does those other diagrams show the pcm coming into the yellow line near the ignition switch?

Cournoyer wrote: does those other diagrams show the pcm coming into the yellow line near the ignition switch?

No.

when I pull out the starter relay under the hood in fuse box and put a test light in terminals after checking ground and making sure light works ( it did) There is no power in any of the 4 pins of the relay terminal and when in run and crank position there is no power in any of the 4 pins in the terminal

With the starter relay removed, there should be 12v terminal #30. If you have no power here, the problem is BEFORE the ignition switch.

And, if there is no power on terminal #86, with the key in the "START" postion, I would say, the problem is BEFORE splice s163.

that #30 is dead at the relay so i will check that yellow wire thank you

I removed positive post bolt on fuse tray and flipped tray to look under it and all wires look good at the relay 302 on the underside. After that i put tray back in and reconnected positive post on fuse tray box and hooked up the battery terminals . I now have power (12v) at the #86 relay post when in start position. I also have power at the number 30 post (12v) with the key in run .(is there supposed to be power at #30 with key in run ) when i check the power on the start post solenoid wire down by the starter I get 11.4 volts in start position with it not connected to the solenoid . when i connect it i get less than 1 volt while in start position on the key. I did cut the start post wire back and put a new connector and no difference car wont start. ps i did make a jump wire 10 gauge with new ring post connector and hooked it to start post on starter and with the key in run position i can touch the positive battery post and the car starts right up. I have also switch the relay with others in the box with same number. could you give me somemore feed back im at a loss. thanks Rich ps again this car sat in a garage for 4 yrs out of the weather and looks like new and only 68,800 miles on it

Cournoyer wrote: (is there supposed to be power at #30 with key in run )

Yes. #30 should have power all the time.

when i check the power on the start post solenoid wire down by the starter I get 11.4 volts in start position with it not connected to the solenoid . when i connect it i get less than 1 volt while in start position on the key

This suggests high resistance in the yel/lt blu solenoid wire. Check the connection at the relay and the solenoid. Possibly, corrosion inside the wire coating. To rule out a shorted solenoid , you could hook up a head light, or some other electrical load, in place of the solenoid.

I should add that the voltage drop COULD be occurring ANYWHERE on the power feed,....From the Battery to the solenoid, including the relay, itself. Does the voltage at the 50amp fuse drop when cranking?

i did put a new connector on the starter wire down by the starter yellow with stripe and when i had the fuse tray upside down i saw no visual sign of corrosion on that yellow wire with stripe under relay #87 how can my solenoid be bad if i can jump it with a wire to that battery positive and she starts right up? if i pull out the relay can i jump 86 to 85 and 30 to 87 and try to start the car ? is there any way the pcm is involved with this problem even though it is at the end of the circuit on the control side? thanks Rich

i did not check if the voltage drops at the 50 am while cranking do i just pop the clear top off and touch positive lead to fuse through meter to ground i never tested a super fuse Rich

Cournoyer wrote: how can my solenoid be bad if i can jump it with a wire to that battery positive and she starts right up?

Good point.:whistle: Lol

if i pull out the relay can i jump 86 to 85 and 30 to 87 and try to start the car

30 to 87, yes....86 to 85, NO!

is there any way the pcm is involved with this problem

Pin 44 of the PCM Should supply a ground to the relay. If it is, then the PCM is not the problem. A way to test everything else involved would be to ground pin 44 by back probing the PCM.... With the key in the start position and the gear selector in Park or Neutral, Pin 86 of the relay should have power. The computer grounds pin 85. The relay closes. At this point, you should have battery voltage on pins 86, 87, and 30. Pin 85 should have a ground....the starter should be cranking.

Cournoyer wrote: i did not check if the voltage drops at the 50 am while cranking do i just pop the clear top off and touch positive lead to fuse through meter to ground i never tested a super fuse Rich

You can do that, or pull the fuse and reconnect it with jumper wires.

should the car start if i do all that while grounding pin 44 at the pcm ? also i have tried to jump 30 to 87 and get no start at all

Yes. It should start. I mentioned grounding pin 44 only for informational purposes. I, really, don't think the PCM is the problem. You have a major voltage drop on the solenoid power feed. This is where we need to concentrate. To cut to the chase, if there is power at the 50 amp fuse and you pull the relay and jump 30 to 87, the starter should crank. End of story. However, your voltage is dropping from battery voltage to less than 1 volt. We need to find WHERE it is dropping.

This is, definitely, worth watching.

i agree i thought about bypassing the yellow wire with stripe to solenoid altogether ! using my 10 gauge jump wire . but you are telling me that the load drop could go all the way back to battery through the 50 amp fuse i will check voltage wile in start on that fuse. when i visually looked at # 87 pin under side that connector looked ok how do i pop those connectors out out the box to get a better look ? today i tried to probe the yellow wire right past the #87 underside while in start and i got low voltage i will try that again tomorrow i may have not had enough contact on the copper part of the wire.