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Car Won’t Shut Off - Cluster also on ign off with battery power

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    Car Won’t Shut Off - Cluster also on ign off with battery power

    Hey R3V-

    I am having trouble diagnosing a weird issue that didn’t exist a few months ago.

    As soon as I hook a battery up to the car with ignition off, the cluster is powered.

    The car also will not shut off with key when running. When the key is turned off when the car is running, the battery light is illuminating.

    So, something is backfeeding the exciter circuit with both the car on and off.

    I swapped the alternator with a known good - did not fix.

    Swapped ignition switch, no change.

    Thought maybe SI batteries failed and ruined the board. Changed cluster with known good, still no change.

    The car had an aftermarket alarm previously that I completely removed and made sure nothing funky was going on with wiring.

    What else could back feed the exciter circuit?

    Thanks all-
    1990 Brilliantrot 325iS Build Thread
    1989 Zinnoberrot M3 Build Thread

    #2
    Could it be a relay stuck open. As in always in the on position?

    88' Seta 2.7i

    https://www.r3vlimited.com/board/for...430-my-88-seta

    Comment


      #3
      Originally posted by It's Soda Not Pop View Post
      Could it be a relay stuck open. As in always in the on position?
      Yes, I just haven’t had time to dip into the ETM and see which relays have the ability to back feed the circuit, so this thread was an attempt to shortcut my diag.
      1990 Brilliantrot 325iS Build Thread
      1989 Zinnoberrot M3 Build Thread

      Comment


        #4
        as a crap shoot how is the alternator ?

        ignition switch / tumbler, SI board, and alternator have all been linked to a no shut off. no doubt i'll have to deal with all three myself.

        Comment


          #5
          Originally posted by 82eye View Post
          as a crap shoot how is the alternator ?

          ignition switch / tumbler, SI board, and alternator have all been linked to a no shut off. no doubt i'll have to deal with all three myself.
          I changed ignition switch, alternator, and cluster with known good units from hoopty with no change, sadly.
          1990 Brilliantrot 325iS Build Thread
          1989 Zinnoberrot M3 Build Thread

          Comment


            #6
            has anyone messed about with the battery distribution block wiring? i had a car come in once, where someone gave the ground wires 12v, and the car did the same thing - acted as if the ignition switch was in the "run" position all the time. food for thought. would also inspect the K5 and K7 relays.
            '72 2002 pickup | '88 M5 | '89 330is | '89 M3 | '01 Z3M | '11 328xi-t

            Comment


              #7
              Originally posted by e30austin View Post
              has anyone messed about with the battery distribution block wiring? i had a car come in once, where someone gave the ground wires 12v, and the car did the same thing - acted as if the ignition switch was in the "run" position all the time. food for thought. would also inspect the K5 and K7 relays.
              Thanks man! Inspected K5/K7 this morning, all was well. This was a new thing that happened after the power distro was assembled.

              Back when I first got the car, my buddy who put it together couldn't get it running. I went over to help with diag and found the 13 button OBC module unplugged. Plugged it back, in and it fired right up. Always thought it was funny that it was unplugged.

              ANYWAY, with that in mind, I swapped out the 13 button OBC module with a spare, and whala, all was fixed. My guess is that it was a problem before as well, hence it being unplugged, but it didn't show up until I ran the car a bit more.

              What an odd failure. Glad I found it!
              1990 Brilliantrot 325iS Build Thread
              1989 Zinnoberrot M3 Build Thread

              Comment


                #8
                Originally posted by AWDBOB View Post

                Thanks man! Inspected K5/K7 this morning, all was well. This was a new thing that happened after the power distro was assembled.

                Back when I first got the car, my buddy who put it together couldn't get it running. I went over to help with diag and found the 13 button OBC module unplugged. Plugged it back, in and it fired right up. Always thought it was funny that it was unplugged.

                ANYWAY, with that in mind, I swapped out the 13 button OBC module with a spare, and whala, all was fixed. My guess is that it was a problem before as well, hence it being unplugged, but it didn't show up until I ran the car a bit more.

                What an odd failure. Glad I found it!
                I never knew that it would keep a car from cutting off. I knew it could prevent from starting.

                88' Seta 2.7i

                https://www.r3vlimited.com/board/for...430-my-88-seta

                Comment


                  #9
                  I just saw this thread. Glad you found the problem!! I had a similar issue where car would not shut off and stayed running. When battery was connected, dashboard lights were on as if key was turned to ACC. Replace a lot of parts and ended up being a low charged battery and negative terminal being loose. My negative terminal was loose because I would disconnect negative cable from the battery when the car would sit for a while.

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