Mopar dies when key is released

Electrical and Ignition

  1. Bulldozer

    Bulldozer free ice cream sandwiches

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    I don't advocate throwing parts either , but toss a new ECU at it and I bet it starts. speaking from experience . make sure ALL your grounds are GOOD first. the ECU gets its ground from the body , which comes from the battery to block to body in most cases
     
  2. 67Dart273

    67Dart273 FABO Gold Member FABO Gold Member

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    1--If you have to, get a pin or other sharp probe, and puncture the insulation on each side of the link. With key in "run" if you only get power on one side,it's bad

    2--No. Starter relay is thus:

    Largest stud is battery

    "square" screw feeds power to solenoid on starter when relay is engaged

    one "push on" terminal goes down to neutral safety switch on trans

    Remaining push on terminal receives "start" from ignition switch
     
  3. 67Dart273

    67Dart273 FABO Gold Member FABO Gold Member

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    Sorry, but IF the situation is as the OP describes ( runs with key in start) there is ZERO possibility that the ECU is bad.
     
  4. KitCarlson

    KitCarlson Well-Known Member

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    My experience suggests a voltmeter is a wonderful tool, it put an end to unnecessary part changing and guessing.
     
  5. RustyRatRod

    RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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    Yeah cause then it wouldn't run at ALL. He's simply lost the signal from the ignition somehow. He gets 12V in the start position. My immediate reaction was ballast resistor. I wonder if he tested the new one?
     
  6. A340

    A340 Well-Known Member

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    67 Dart Relay has no post. See pic. And YES I tested the new Ballast resistor also.
     

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  7. Bulldozer

    Bulldozer free ice cream sandwiches

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    i just remembered a 69 imperial I had that would only start and run if the key was held down and would die when you let off . it turned out to be the ignition switch.
     
  8. 67Dart273

    67Dart273 FABO Gold Member FABO Gold Member

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    OK< as I told you earlier, I'm not specifically familiar with "the later stuff"

    The only difference is that the later relay added a second contact, and the pin marked "ballast resistor" now became the ballast resistor bypass circuit. That terminal goes essentially directly to the coil + and supplies starting voltage to the ignition circuit.

    I'm certain that your problem is between the ignition switch --harness connector -- bulkhead connector--and the "run" buss out in the engine bay.

    Without a GOOD wiring diagram I cannot give you more specifics.

    You should be able to ID where that wire comes through the bulkhead, probe that, and determine if you have power there. If (seems to be) there is a fuse link, that would be suspect
     
  9. RustyRatRod

    RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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    You got a two day old thread here. Don't know if you're askin about this elsewhere, but you have time wrapped online. Not bein a smartass.....but turn the computer off. Get the test light and go find the problem. I could find the break in power in 15 minutes or less. 1982 truck. That's like stones and bearskins. You should try a pinout diagnosis on a 2012 BMW. Two things. It aint gonna fix itself and it's gonna take you some time depending on your skills. We caint fix it over the internet. I wish it was that easy but it aint and even if it was, you wouldn't learn anything.
     
  10. A340

    A340 Well-Known Member

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    RatRod: I hear Ya! If you notice, my post started at 10:20 last night. I spent the previous 4 hours with a volt meter doing just what you described. I've been at work all day today, trying to get tips and ideas so when I get off work in 2 hours, I can spend more time with this thing. I never imagined it would be this tough. I have done this before on other cars and usually find the problem within 30 minutes. This particular one is just driving me up a wall. Will let you know the results (hopefully) later on tonight or tomorrow. Thanks for the encourgement!
     
  11. RustyRatRod

    RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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    A volt meter is great, but in a case like this, you're lookin for ON or OFF. A test light will be much easier to manipulate. Trust me.
     
  12. 64ragtop

    64ragtop Well-Known Member

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    Looking at suspected problem parts is no substitute for TESTING them. Fuses and fusible links fail but don't look bad. New parts can be bad from the parts store. But you know all this.

    The bulkhead connector terminals can get pushed back in their cavities and make intermittent contact and fail. And when they do, it's really hard to find. Unplug the bulkhead connector, then pull FIRMLY on each wire to assure they're all securely fixed in place and do the same under the dash. While you have the bulkhead connector apart, clean the terminals and spray some white lithium grease into both sides. The grease keeps moisture out and prevents corrosion.

    You're in the right area - you'll find it. Let us know!!

    BC
     
  13. carcrazyguy

    carcrazyguy Well-Known Member

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    Just had the same issue on a car. It turned out to be the ignition switch. Installed a new one and it is good to go and starts better than ever before now!
     
  14. A340

    A340 Well-Known Member

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    OK Guys, Now have the answer. This has got to be the craziest, most unbelieveable, just plain dumb luck, one could ever find! Took me about 30 minutes tonight to find this. Checking all the 12v ignition wires again with my 12v light. Reading from the wiring diagram and checking each wire from the ignition switch out. NOTHING checks out! Started checking the fuse links by pulling on each end to see if I get a broken or mushy wire. NOTHING! By CHANCE I went past the FuseLink toward a connector and found a mushy sleeve. Pulled on it and it split in two. The outer sleeve had no signs of a break or burn. Now here is the crazy part. According to my wiring diagram this is a white wire that comes out of the bulkhead and ties into 4 wire connector. This wire feeds the Windshield Wiper motor & Switch according to my diagram. Jumped this wire and it started right up. Attached are pictures of what I found. I hope no one ever runs into this kind of mess. Appreciate all your help and ideas.

    A340
     

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  15. 67Dart273

    67Dart273 FABO Gold Member FABO Gold Member

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    I learned a long time ago to "wiggle things"

    [​IMG]
     
  16. mbaird

    mbaird mbaird

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    Thats what I was thinking...I once replaced a turn signnal switch after installing a NEW flasher.... Turned out the new flasher was bad as well!
     
  17. eestatic

    eestatic Well-Known Member

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    I experienced same issue a few years back and found fusible link hidden (routed in wire mold) mushy looking. When I squeezed the link I could tell it was nothing in there. Also if you have good light,sometimes they will be a tad different color/hue than rest of wire...heat effect I guess.
     
  18. roccodart440

    roccodart440 Well-Known Member

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    or.. run 2 wires to the battery and one to any key switched 12 volt line and call it a day. :cheers:
     
  19. memike

    memike Super Moderator Staff Member FABO Gold Member

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    Wow!! I still can't wrap my head around this :sign3: why the circuit you repaired fixed it.
    I need to read it again I guess, and see how the harness stopped feed to your ignition
    12 volt supply ... Very very happy to see you have it up and running :cheers:
     
  20. Divenut

    Divenut Well-Known Member

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    Really happy to see you got it sorted out A340! Good job.

    Pat
     
  21. A340

    A340 Well-Known Member

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    Memike: If you can figure that out, I would like to know also! Now you can see why this was driving me nuts. Nothing seemed to make sense. I thought about retracing that circuit, but I was sooo glad I found it, I left well enough alone!
     
  22. roccodart440

    roccodart440 Well-Known Member

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    I see it, 3 posts above mine. Glad he found the current problem.

    Just remember next time the stock system fails how nice a 3 wire hot bulletproof ignition is.

    Mods realy shouldnt' be calling people stupid that are trying to help, especially when the issue was missing a post, not ill advice or false info.
     
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