my 75 lesabre won't start

Discussion in 'Street/strip 400/430/455' started by deenice, Jun 20, 2018.

  1. deenice

    deenice buick lesabre 1975

    took my car for a drive came home parked it...went to start it back up and nothing..I checked my battery and starter connections every thing is good...so I'm thinking fuse?...any other suggestions
     
  2. flynbuick

    flynbuick Guest

    Check the battery voltage. Modern batteries can go away quickly. If it checks out we can go to the next step.
     
  3. Schurkey

    Schurkey Silver Level contributor

    There's a HUGE difference in diagnosis between "Won't Crank" and "Cranks, but Won't Start"

    DOES IT CRANK?
     
    Houmark likes this.
  4. deenice

    deenice buick lesabre 1975

    no...car completely dead...im thinking fuse
     
  5. Luxus

    Luxus Gold Level Contributor

    Check the obvious first like the battery condition. Then look for bad connections. Common one is at the battery, especially if you see a lot of corrosion. In my case the connection at the starter was FUBAR.
     
  6. Brad Conley

    Brad Conley RIP Staff Member

    Fusible Link wire. It is in the wire loom that runs across the top of the engine in a tray next to the passenger side valve cover, down the front to the starter.
     
    deenice likes this.
  7. deenice

    deenice buick lesabre 1975

    I checked all of that
     
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Do the headlights, horn, interior lights work?
     
    john.schaefer77 likes this.
  9. Schurkey

    Schurkey Silver Level contributor

    Thousands of years ago, GM would use the horn relay as a distribution block for battery power. A bad connection at the horn relay would disable power to most of the vehicle. As it happened, I had a car with a loose connection there...sometimes I had power to the headlights and interior lights, but the surge required to crank the engine would kill power to practically everything.

    Later, GM used the + post on the starter as a distribution point. A wiring diagram would tell the tale on yours.

    Yup, fusible link wire, discharged or defective battery, corroded cables, loose connections could each be some or all of the problem. Battery terminals can be tight and with no "soft" corrosion, yet make no contact because of "hard" black corrosion.
     
    Harlockssx likes this.
  10. Mark Demko

    Mark Demko Well-Known Member

    Start at the beginning, the battery.
    Disconnect BOTH cables, check voltage AT the side terminals, gotta have power there for ANYTHING to happen.
    If battery checks ok, check cable ends for corrosion, peel back the rubber/plastic insulator on terminal ends, EVERYTHING needs to be corrosion free.
    Side terminal cable ends are notorious for hiding corrosion!
     
  11. deenice

    deenice buick lesabre 1975

    no
     
  12. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    That points to blown fusible links. Along with the + battery cable, there are 2 main feed wires that bolt onto the big lug of the starter solenoid. One is 10 gauge, the other is 12 gauge. Both have fusible links, sections of wire that are designed to sacrifice themselves in the case of a major short. The bigger wire powers everything it the headlights, the smaller feed wire powers just the headlights. Assuming you checked that your connections at the starter are clean and tight, the fusible links are blown. The question is why. Were you doing any electrical work on the car preceding this problem? You will need to remove the wires from the starter, clip off the bad fusible links and replace them. NAPA sells replacements. Do a search on V8. This has been discussed before.
     
    john.schaefer77 likes this.
  13. flynbuick

    flynbuick Guest

    I have seen this happen when the battery hold down clamp was mia and the battery was moving around grounding the positive terminal.
     
  14. deenice

    deenice buick lesabre 1975

    thanks....I have electric fans...other then that...I haven't done any electrical work on it
     
  15. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    To fry both fusible links takes a major short.
     
  16. flynbuick

    flynbuick Guest

    Did you upgrade your stock wiring to handle the increased current load due to the addition of electric fans? If not, look to see where the fan circuit may have caused a meltdown that led to blowing the fusible links.
     
    deenice likes this.

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