Another stupid digital to analog swap question,


  • Another stupid digital to analog swap question,

    So I have a 1987 N/A GLL,started with the digital but after I broke the tach I figured it was time for an analog swap, hoping to keep this car a long time and I don't wanna have issues down the road. This started a terrible cycle of trying different harnesses and clusters. So the first cluster and harness I tried was the analog out of my 85 N/A with it's harness, all sorts of weird stuff happened including the headlights having a seizure,the dash illumination clicks on then the the clearance illumination fuse blows and it stops working, lights get stuck in whatever position they were in. After swapping back I searched for solutions and decided to pick up a 1987 analog for the best chance of compatibility, it also does weird (but totally different) things. First thing it does is when the key is on the right turn signal indicator on the cluster stay on, when headlights are turned on the left turn signal and brights indicators stay on. Lights stay up as long as the cars on and turn signals function and relay clicks. Still no illumination. So in order to still be able to drive it (I have to daily it, it's literally my only way to get to work.) I tried on a whim using the 85 dash with the 87 harness and I get tach and no weirdness, no illumination still but fuel gauge works and so does the temperature, turn signal indicators work as expected. No speedometer but I think the cable I swapped in was broken. I have swapped out the fuel sender unit and bypassed the stop/headlight sensor as suggested by many online guides. There are three of us working on the car and BEFORE it's suggested I have all the FSMs and we have poured over their terribly vague diagrams for hours just to find no answer to why this still isn't working. Everyone who has a write-up or guide is either for the earlier models or the guide has disappeared from the internet. almost all results I've found are someone asking a question like mine and 3 people hastily replying "Get the FSM" without any further helpful information. I signed up for this forum in hopes of finding anyone who might have any leads on something that might have blown when I put in the 85 harness and cluster or maybe something I haven't swapped in that could explain this weirdness. all fusible links are tested and good. At this point I either need an expert or a priest. If anyone has done this on a 87-89 before and had success I would really appreciate just a confirmation that it can be done.

  • #2
    "1987 N/A GLL,started with the digital but after I broke the tach, it was time for an analog swap "

    So repairing the tach was not an option? 20 years ago making this swap was not impossible because you could buy a NEW harness … and we had good access to the parts catalog … ( z31.com )
    now these parts are NLA … and the NOS is gone … and the used parts are not reliable… It's hard to believe but the z31 was on the bleeding edge of automotive electronics …
    Last edited by dbruce; 07-30-2018, 10:42 AM.

  • #3
    Originally posted by dbruce View Post
    "1987 N/A GLL,started with the digital but after I broke the tach, it was time for an analog swap "

    So repairing the tach was not an option? 20 years ago making this swap was not impossible because you could buy a NEW harness … and we had good access to the parts catalog … ( z31.com )
    now these parts are NLA … and the NOS is gone … and the used parts are not reliable… It's hard to believe but the z31 was on the bleeding edge of automotive electronics …
    So when I say I broke the tach I mean I literally dropped the cluster and fractured the VFD in the tachometer. As you probably know repairing a VFD is next to impossible and knowing that I was likely to have to repair the power supply and replace the cluster over and over again for the entire life of the vehicle I tried to go ahead with the analog swap. In hindsight yes, just buying a working digital dash would have probably saved me some amount of trouble but I already had the parts car with a known working analog. The 87 analog was also out of a known working car as I tested it before I pulled it from the guys car who I bought it from.
    Last edited by redturner15neo; 07-31-2018, 05:46 AM.

    Comment


    • dbruce
      dbruce commented
      Sorry, I wasn't helping …