'72 350 Starter Conundrum

Discussion in 'Small Block Tech' started by Colt-Tx, Feb 26, 2020.

  1. Colt-Tx

    Colt-Tx Member

    I will apologize for the length now but it seems you guys like details in trying to diagnose an issue. I have a '72 skylark custom that I bought my kids to drive. My daughter drove it for 2.5 years in high school with no problems. It has been driven about once a month for the last year and now my youngest just got his license. I went to do the normal dad check and make sure that everything was good before I put him on the road and here is where things went side ways. I started it up first try with a little starter fluid. It ran fine for 5 minutes. I turned it off. I tried to start it 30 minutes later and just heard a click, click, pause click, pause click, click. If I try again nothing. If I wait 3-5 seconds I hear the same click/engage with no turn over. So started diagnosing the issue. Took cover inspection plate off of tranny and tried again. I see the bendix engage the motor and try to spin the flywheel, it doesn't move. The bendix sometimes gets stuck engaged and only pops back when I turn the motor over by hand. So now I am thinking worn out starter. Here is the part I don't understand that I am hoping someone can shed some light on: I noticed that if I tried to crank the motor immediately after an attempt it would do nothing. I also noticed that my dome light would go dim. If I waited 5 seconds my dome light would become bright again and I could try to crank and get the clicks. I put a meter on my battery (it is a few months old by the way) and it read 12.8V. So I tried a second test .... I put on the headlights. I cranked the motor. Click click click. I stop and my headlights turn off. I wait 3-5 seconds and my headlights turn back on and I can attempt again. Do I have a bigger electrical issue going on or could this be a symptom of a wore out starter. Anything else I can do? Suggestions? I just don't want my new driver going out in a car that might have an electrical issue. thanks in advance to all the gear heads that are so much smarter than I am.
     
  2. alec296

    alec296 i need another buick

    Sounds like a loose battery terminal or battery cable issue. Could also be a ground cable problem.
    Side post terminal battery cables do corrode internally as the batteries seem to leak acid from the terminal into cable more often then ever.
    So check contact on terminals , check / test battery. Just because it reads 12.8 doesn’t mean it’s got enough power to handle a load of 200-300 amps during cranking.
     
  3. lemmy-67

    lemmy-67 Platinum Level Contributor

    If you have a dashboard ignition (doubtful if car is a 72), the contacts in the ignition switch wear out over time & build resistance, so you don't get all the juice from the battery when cranking. Over time, the whole thing can short out & the car will die while driving (has happened in my 1980 chevy van several times).

    Check/replace your battery cables, coat the terminals with copper grease & use those alkaline washers to absorb any leaking acids, and consider a mini-starter. I've installed one in my 67, had zero starting issues for the last 10+ years.
     
  4. Colt-Tx

    Colt-Tx Member

    Thanks Andy, It is a new battery and I actually took the battery out a week ago and took it to autozone to have it charged and tested since my battery charger seemed to be acting funny. It is a top post battery and one spec'ed for the car but does seem small IMO. (Duralast Gold 86FT-DLG 800 CA, 640 CCA) As for the cables they are old and not the nice clean connectorized cables but ones that have the mechanical bolt on terminals by the battery and appeared like good solid connections by the starter. There may be an issue further up since the car has long tube headers and there is little to no room for the starter and cables.
     
  5. Colt-Tx

    Colt-Tx Member

    Thanks Lemmy, No Dashboard Ignition here. Correct me if I am wrong but the large power draw for the starter comes directly from the battery cable not the ignition cable. The power from the ignition path is only for a relay that then provides power to the solenoid and starter motor powered from other paths. That draw should be fairly small for the relay. Is the mini-starter actually smaller in all dimensions than a OEM starter. It appears that the face plates on the mini's are larger than OEM and would not clear because of the long tube headers.
     
  6. telriv

    telriv Founders Club Member

    STOP the messing around. CLEAN THE BATTERY CABLES & THE BATTERY CONNECTIONS 1ST. BEFORE DOING ANYTHING ELSE. You have to start somewhere, & this is basic, & cleaning the posts & cables are something that's easy & costs zero $$$$. Then you can go from there.
     
    Ziggy, Darron72Skylark and alec296 like this.
  7. Colt-Tx

    Colt-Tx Member

    Thanks Tom. They are spotless so it is not a cleaning issue.
     
  8. LARRY70GS

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

    You have a problem with a bad connection. If you are certain that the battery connections are clean and tight, then the problem is at the starter. loose, dirty, or damaged connections and or cables. Look again
     
    1973gs and Darron72Skylark like this.
  9. telriv

    telriv Founders Club Member

    They appear "Spotless" or did you actually take them off & check & clean. I can't tell you how MANY TIMES I made that mistake & by the looks "Assumed".
     
    Darron72Skylark likes this.
  10. stk3171

    stk3171 Well-Known Member

    Try hitting the starter with a hammer a few light wacks. the start it. Brushes may be stuck.
     
  11. stk3171

    stk3171 Well-Known Member

    also the points in relay may be worn out.
     
  12. stellar

    stellar Well-Known Member

    Sounds like a bad battery. Did you try jumper cables or a different battery? You turned the motor by hand so it isn't frozen. If it doesn't start with a jump, the starter fields may be toast.
     
  13. Fox's Den

    Fox's Den 355Xrs

    How about the big ground strap that is connected to the trans at the back. Is that connected to the firewall? That will give problems too and it does sound like there might be a bad starter connection. Take the starter out clean it up put some grease on the ends of the pins put in new brushes.

    Check volt meter while trying to crank the engine you need 9.6 volts at least and you should have 13.8 volts when running with headlights on OR the heater. Make sure the battery is fully charged before doing these tests.

    It is also better to slow charge a battery and not fast charge it. Fast charging will drain the life out of a battery (how long it lasts)
     
  14. pbr400

    pbr400 68GS400

    How long have the ‘temporary’ ends been on the battery cables? Tight but corroded or oxidized may be your problem.
    Patrick
     
  15. 70skylark350

    70skylark350 Jesus loves you unconditionally

    put a multimeter on the S terminal on the starter and check your voltage. if you have 12 volts there when trying to start then the starter is bad. either that or the engine is locked. did you try to turn by hand?
     
  16. Ryans-GSX

    Ryans-GSX Have fun, life is short.

    Dave and I had one hell of a time with my car doing something similar. I had a new battery and multiple starters.

    What we ended up finding the problem was a switch on the lower part of the steering column was old and dirty inside. Just needed taken out and cleaned. You would need to PM Dave Tumas or get him to respond to this thread for help but I would have NEVER figured this out without his help and he did it in just a few min. I have had a lot of Buicks and had never had this kind of problem. You may have something similar and even if you don't it won't hurt to clean this little thing up so you don't have a problem in the future like I did.
     
  17. 12lives

    12lives Control the controllable, let the rest go

    Like Ryan - there is another place where you can lose voltage to the solenoid. The start/ignition wire goes through the firewall connector. Pull the connector apart and blast it with contact cleaner.
    Couple other ideas for trouble shooting: use a jumper cable from the starter motor case to the neg terminal on the battery. That will bypass any bad grounds. Also, run a wire from the positive battery post to the "S" terminal on the starter. That will bypass any bad connections in the start circuit. and be careful!
     
  18. Colt-Tx

    Colt-Tx Member

    Wanted to thank everyone for their suggestions. I ended up replacing the battery cables as they were old and the manual connections looked terrible. Once I did that it fired right up so as for now I think Patrick gets the prize for oxidation on the exposed copper under in the bolt on top terminal connectors were limiting the current draw for the starter. Will keep an eye on it and will update this with any new info. Cheers, Guys.
     
    MrSony and PCUB like this.
  19. telriv

    telriv Founders Club Member

    Who told you to check the connections. As I said you assumed.
     
  20. LARRY70GS

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

    Posts number 8 and 9.:D:D:D
     

Share This Page