Mopar ECU

Discussion in 'Electrical and Ignition' started by barbee6043, Oct 2, 2018.

  1. barbee6043

    barbee6043 barbee 6043

    Messages:
    9,217
    Likes Received:
    2104
    Joined:
    Jul 20, 2008
    Location:
    Shepherd, Texas ( SE Tx)
    Local Time:
    4:28 PM
    When I change over to the ECU , do I splice into the 2 prong ballast at the side where there are the two blue wires, one goes to coil +, other to firewall, which ONE???? Thanks
     
  2. MoparLeo

    MoparLeo NRA PATRON LEVEL LIFE MEMBER FABO Gold Member

    Messages:
    316
    Likes Received:
    148
    Joined:
    Feb 10, 2016
    Location:
    Moreno Valley, Cal. So. Cal.
    Local Time:
    2:28 PM
  3. AJ/FormS

    AJ/FormS 367 FormS clone 3.09-1.92-1.40-1.09-.78od 3.55s

    Messages:
    14,181
    Likes Received:
    3590
    Joined:
    Jan 19, 2014
    Location:
    South-Central Manitoba,Canada, 900ftelevation
    View My Photos
    Local Time:
    4:28 PM
    Or are you asking about the "dual ballast resistor" which has 4 "prongs"?

    I only ask cuz I don't see a thanks on Leo's post
     
    • Thanks! Thanks! x 1
    • Agree Agree x 1
    • 67Dart273

      67Dart273 Well-Known Member

      Messages:
      37,538
      Likes Received:
      5241
      Joined:
      Oct 14, 2010
      Location:
      Idaho
      View My Photos
      Local Time:
      2:28 PM
      Leave the coil PLUS wiring completely alone except for the NEG which of course was to the points and maybe a tach

      The ECU power wire goes to the "high" voltage side of the ballast, IE blue. One side will have brown and blue, that is to the coil. If any question, pull the connection you believe it to be off the ballast, and confirm that wire has "battery" when key is in run.

      Make DARN sure both the regulator and ECU are grounded. Scrape away paint behind the bolt holes, use star lock washers, and consider upgrading the engine to body jumper. I like to use a short "starter cable" that is eyelet--to eyelet about a foot long. Bolt it to the holes in the rear of the driver side head, and to the firewall. One way is to the master cyl. stud
       
    • barbee6043

      barbee6043 barbee 6043

      Messages:
      9,217
      Likes Received:
      2104
      Joined:
      Jul 20, 2008
      Location:
      Shepherd, Texas ( SE Tx)
      Local Time:
      4:28 PM
      Thanks all!
       
    • barbee6043

      barbee6043 barbee 6043

      Messages:
      9,217
      Likes Received:
      2104
      Joined:
      Jul 20, 2008
      Location:
      Shepherd, Texas ( SE Tx)
      Local Time:
      4:28 PM


      Edited> I got it wired by diagram. I have full charged batt. 12.5 v in and out fire wall at the big black and red wires, firewall connections cleans,, I have 12 .3 v at ballast in run Ign on, when I hit start, ign 2, I only have about 8.5 v there at ballast wire cranking. No fire at coil wire grounded to valve cover, New coil and plug wires.
      Next I will do jumper from batt. to coil + and see. IF nothing then, it tells me what!??????? Bad coil ( new)!???????
       
      Last edited: Oct 3, 2018
    • hangn0ut

      hangn0ut Well-Known Member

      Messages:
      702
      Likes Received:
      92
      Joined:
      Dec 3, 2012
      Location:
      rialto.ca.
      View My Photos
      Local Time:
      2:28 PM
      What's voltage at starter relay while cranking?
       
    • barbee6043

      barbee6043 barbee 6043

      Messages:
      9,217
      Likes Received:
      2104
      Joined:
      Jul 20, 2008
      Location:
      Shepherd, Texas ( SE Tx)
      Local Time:
      4:28 PM
      Starting: Big terminal at starter relay: 9.5
      Batt. 12.3
      ballast 11.5
      coil + ; 8.5
      I have 12.4 in and out hot wires at firewall. New coil, amp. gauge bypasses
      I can't find my in line spark tester, but I see no fire with coil wire at valve cover.
       
    • 67Dart273

      67Dart273 Well-Known Member

      Messages:
      37,538
      Likes Received:
      5241
      Joined:
      Oct 14, 2010
      Location:
      Idaho
      View My Photos
      Local Time:
      2:28 PM
      The low coil voltage indicates either the bypass (IGN2) from the ignition switch has a problem or that something is dropping voltage TO the ign switch. This also might be (one of the usual suspects) ..............might be the bypass wire (usually brown) coming through the bulkhead

      I'd check power TO the ign sw in 'crank' and power on the ign2 terminal at the ign switch

      Be CERTAIN the ecu is grounded

      Make certain the ECU is NOT hooked to the coil side of the ballast