what is going on

buffalohorse2buffalohorse2 Member Posts: 1
edited February 2018 in Pontiac
Electricam component by component my interior electrical system is failing. First the entire air system quit functioning. No A.C. no heater just blows air that smells like it came out of the motor. Then the auto-lock system and the car alarm stopped working. Then the dome lights, cell phone plug, and cigarette lighter stopped. THEN there is no longer any fluctuation to the idling when I first start the car. Initially it idles high then levels off to a steady idle at least it used to. Now it idles a fast then slow then fast then slow rythem. Now the background lighting to the dashboard, radio window, and shifting panel board is gone. The oil pressure gauge has stopped. The actual pressure is ok though. My car is a 2002 Pontiac Bonneville SE. Anybody got any suggestions??


  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    I'd start with basics before hunting ghosts. Make sure the battery is load-tested and charged up. How old is the battery? Then I would check the charging system to see if it's putting out correct voltage.

    If both those check out, I'd have a look at the fuse box and harness going in and out and look for damage.

    Also clean and tighten the battery cables and engine-to-frame grounds.

    Computers and modules don't like voltage drops or spikes--they go crazy--so we need to establish that we have a stable voltage in the electrical system.

    Beyond those tests, you may need professional help here with someone reading data in real time as the problems are occurring.
  • imidazol97imidazol97 Crossroads of America I70 & I75 Member Posts: 26,501
    Battery itself is first candidate to be checked.

    A lot of what's working strangely or not working is likely controlled by a body control module, a small computer. There is a rear control module on this car as well. I don't recall the location. But IF the battery checks out, do some internet searching for Pontiac AND Buick leSabres of that year and "body control module problems." I believe there rear is called rear integration module.

    A nice check you might do yourself is to lift the front edge of the rear seat with a jerk and then remove the seat, or prop it upright against the rear of the seat. The battery is there. You can try wiggling both cables where the metal is against the battery to see if there's any looseness. The terminals on the battery itself will likely be okay as far as corrosion. You might tighten them being careful not to touch any metal when you tighten the small bolt on the RED one because that will cause a big short circuit with damage.

    The best thing to do is use a small wrench or socket to remove the black terminal and lay it aside or cover with a cloth so it can't contact the battery terminal. Then you can easily work on the sytem.

    Take a look at the end of t he cable from the BLACK terminal where it bolts to the floor. That is the ground cable and those sometimes got some corrosion.

    There also was a problem in a few cars with the underhood fuse box where the RED battery cable connected to it and its being loose--if I recall correctly. IF you have disconnected the negative cable back at the battery and made sure it can't touch the battery terminal, then you might try loosening then retightening that connection.

    PS. I found the box stores will not remove and replace this battery because it's inside the car and they can have damage claims about the seats and carpet, e.g.. If someone tries to do this replacement themself, get in the car and lift the battery in a safe manner from straight in front of it--don't try to lift it twisting slightly sideways because that's very hard on back muscles. Best to have a second person there to help with the battery after lifting it up out of the frame under the back seat.

    2014 Malibu 2LT, 2015 Cruze 2LT,

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