70 GS convertible top blowing fuses

Discussion in 'The ragtop shop' started by Smartin, Oct 25, 2020.

  1. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    It seems a bit random, but I get lucky if I can cycle the top up and down without blowing a fuse. 95% new wiring in the car, with the exception of the actual switch harness and connector to the switch.

    New pump and motor. Just looking for suggestions. I did see that the connection between the switch and the connector might not be 100% tight. Could additional resistance in that connection cause the fuse to blow?
  2. BuickV8Mike

    BuickV8Mike SD Buick Fan

    Maybe bypass the switch and see? Does the top work without the key in 70?
  3. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    It does not.

    I bled the pump and lines some more, and I’m not having the issue now. Just trying to get it operational for the top guy next week.
  4. pbr400

    pbr400 68GS400

    Is it blowing fuses or tripping the breaker? I did’nt think any fuses were in the top circuit. If it keeps tripping the breaker, you probably need a rebuilt motor.
  5. BuickV8Mike

    BuickV8Mike SD Buick Fan

    I wonder if it needed a few cycles to get "burned in". Glad it seems good. :)
  6. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    If you're running topless at the moment it'll only be worse once the fabric is installed and there is a bigger load on the motor. I would clean and grease all the joints. Beyond that i would run wires directly to the pump with the same size fuse inline and see if it still blows. Essentially eliminating the harness and switch and bench testing the motor.
  7. telriv

    telriv Founders Club Member

    IF I remember correctly it did NOT have a fuse, BUT a circuit breaker. IF it keeps tripping it could be loose connections somewhere causing an undue amount of electrical consumption. Is the wiring up to snuff?? Just because it's new wiring
    doesn't mean it's the correct gauge wiring which will/could cause more resistence.
    mrolds69 likes this.
  8. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    Well, I keep blowing 20amp fuses in the fuse box, and the top stops working. I don't recall seeing a circuit breaker anywhere on this car. I had it down to a bare shell. All new reproduction wire harness, with the exception of the original pig tail for the switch itself.

    Once I lubed and adjusted everything on the top frame, things seemed to settle in and no more fuse blowing.
  9. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    That might be part of your problem. I believe the pump should have a 40 amp breaker. 20 won't cut the mustard
    mrolds69 likes this.
  10. mrolds69

    mrolds69 "The Cure"

    Without looking at my car...I think kind of what Joe said. A circuit breaker, no fuse. I also think my top works w/o the key. Again, without looking, I think you have the power wire plugged into the wrong place on the block, that's why you are blowing fuses.
    pbr400 likes this.
  11. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    hmmmm...I'll check on that. Thanks guys
  12. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    I worked on a convertible Cadillac a few years back. The top was on the same circuit as the power seats. It had power all the time. I'd assume the Buick to be the same.
  13. Daves69

    Daves69 Too many cars too work on


    There should a breaker fuse in the power accessory slot top left in my picture.

    mrolds69 likes this.
  14. mrolds69

    mrolds69 "The Cure"

    Yes Adam, like what Dave posted. The problem is if you have a lot of power stuff you need a splitter. Like if you have PW, PS, or? I think seats worked w/o the key. Buicks had an extra wire (pink) for PW that went to a relay. The relay was only live when the key was on. There's some pics and stuff on the PW page on George's site.
  15. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    Yep, as soon as Frank said I was plugged into the wrong power port, I knew where it should go.

    It really sucks when you aren't the one who took the car apart...and there isn't a clear wiring diagram on the convertible top wiring.

    Got it fixed, guys. Thanks!!
    Mike Sobotka, pbr400 and Brett Slater like this.

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