Results 1 to 16 of 16

Thread: Electrical issues.

  1. #1
    Supporting Member Turbo Mopar Contributor rx2mazda's Avatar
    Join Date
    Apr 2006
    Location
    Baltimore,MD
    Posts
    2,925

    Electrical issues.

    Car is a GLH-T with a TIII engine and a bigstuff3 ECU. Car also has a Odyssey PC680(small)Batteryand a power distribution/relay box from a Ford Crown Vic.

    I'm trying to find out why my car keeps eating alternators and or 40 amp ignition fuses. During regular low rpm driving the car is fine and is charging at 14.3V. The problem occurs when you rev the engine. It will blow the 40 amp ignition maxi-fuse or destroy the alternator or both. I went through 2 alt in 1 day.


    I was doing some tuning pulls on Monday night and everything was fine. Did 3 3rd gear pulls to 7k rpms and everything was fine on the data log. Voltage stayed a constant 14.3-14.4 Volts throughout the pulls. On the last Pull I revved to 7.5rpms and let out when I shifted. I didn't know it then but my alternator crapped out then. Noticed the next morning when I went to start it and the battery was weak. I went back and looked at the voltage on my data logs and I can see it drop out when I shift. Thought maybe it was the external VR so I changed it but it wasn't that. Took the Alt off and to a shop and they said the rotor was shot on it. I told them to rebuild it. I had another ALT with a internal regulator mod that I stuck on to check everything. Got it running and the car was charging fine. To test it I revved the motor up to like 7k while idling, gauges went crazy and the car shut off. Looked and I blew a 40 amp maxi-fuse. Replaced it and started the car but now it's not charging. Took the alt back to the shop and they said the internal VG was shot. They replaced that and I took home both Alts, one internal VR and one external VR. I put the internal VR one back in and went for a cruise. Car was running fine and I was babying it for about 45 min. When I got close to home I revved it out to about 5k and the car shuts off when I go to shift. Ignition fuse blown again, I replace that and start the car. To my surprise, the Alt is still charging. Now, I'm scared to rev the thing. Need to find out whats going on. I did redo my battery to frame ground as the one that was there was small....this was before the last blown fuse.

    Things to note....

    1.only does it at high(er) RPMs.
    2.only does it when I let off.(never during accel)
    3.blows ignition circuit maxi-fuse. Only blows the ignition fuse when I have the internal VR alt on. When I'm using a external VR it just destroys the Alt, not the fuse.
    4.usually destroys the ALT

    If you a good with electric circuits and can point me in the right direction that would be great. I'm really stumped/drained right now and could use another brain(s) helping me lol. On the plus side, I've gotten really good at changing my ALT in this cramped engine bay. Thanks!

  2. #2
    Mitsu booster
    Join Date
    Feb 2013
    Location
    Monroe Wi
    Posts
    23

    Re: Electrical issues.

    By no means am I a guru, but i would suggest replacing the battery with a new 500cca battery. In the past when I have had multiple alt failures the battery has been the issue. Most likely caused by high resistance.

  3. #3
    Super Moderator Turbo Mopar Staff 135sohc's Avatar
    Join Date
    Aug 2008
    Location
    SoMd
    Posts
    6,178

    Re: Electrical issues.

    What type of alternator ?

  4. #4
    turbo addict
    Join Date
    Dec 2011
    Location
    Hemet,CA
    Posts
    1,636

    Re: Electrical issues.

    any chance your alternator pulley is not what its designed to be and you are spinning the alternator at some unbelievable rpm?

    how modified is your electrical system?

  5. #5
    Supporting Member Turbo Mopar Contributor rx2mazda's Avatar
    Join Date
    Apr 2006
    Location
    Baltimore,MD
    Posts
    2,925

    Re: Electrical issues.

    ND alternator, stock pulley. Just replaced fuse able links with relay/fuse box .
    Carroll

    SILVER, 85 GLH-R/T, TIII powered, Fueltech, ID1300's. PTE5857
    RED, 91 Spirit R/T - Holset HE351 - 12.6 @ 107...R.I.P.



  6. #6
    turbo addict
    Join Date
    Dec 2005
    Location
    Mesa, AZ
    Posts
    7,351

    Re: Electrical issues.

    What kind of alternator to battery cable are you using? What kind of ground cables are you using? What kind of cable did you use use from alternator/battery to power distributor?

  7. #7
    Supporting Member Turbo Mopar Contributor rx2mazda's Avatar
    Join Date
    Apr 2006
    Location
    Baltimore,MD
    Posts
    2,925

    Re: Electrical issues.

    New 4 gauge. Except the Head to chassis which is a thick grounding strap.
    Carroll

    SILVER, 85 GLH-R/T, TIII powered, Fueltech, ID1300's. PTE5857
    RED, 91 Spirit R/T - Holset HE351 - 12.6 @ 107...R.I.P.



  8. #8
    turbo addict
    Join Date
    Aug 2009
    Location
    Myrtle Beach, SC
    Posts
    2,133

    Re: Electrical issues.

    Is that the only engine ground? If so its probably way too small.

  9. #9
    boostaholic
    Join Date
    Dec 2012
    Location
    Houston
    Posts
    1,265

    Re: Electrical issues.

    anyone looking for battery cables: http://custombatterycables.com/

    They build and ship really quick. Normally priority 2 day shipping.

    You can navigate to the custom battery cable section and choose length, color, terminal size, cable type.

  10. #10
    turbo addict
    Join Date
    Dec 2005
    Location
    Mesa, AZ
    Posts
    7,351

    Re: Electrical issues.

    I like 1/0 gauge, over kill it. For starter to battery, battery to alternator, and ALL ground cable.


    http://www.ebay.com/itm/181074818504...84.m1497.l2649

    http://www.ebay.com/itm/261298170208...84.m1497.l2649

    http://www.harborfreight.com/hydraul...ool-66150.html

    And two battery terminal that you can get at your auto part store.


    Stock Omni alternator wire vs aftermarket.


  11. #11
    turbo addict
    Join Date
    Dec 2011
    Location
    Hemet,CA
    Posts
    1,636

    Re: Electrical issues.

    any odd possibility that the alternator electrical connections (on the alternator) are physically touching something that is ground i.e. chassis/brackets, etc.. during the high rpm acceleration/letting off gas

  12. #12
    Supporting Member Turbo Mopar Contributor rx2mazda's Avatar
    Join Date
    Apr 2006
    Location
    Baltimore,MD
    Posts
    2,925

    Re: Electrical issues.

    Quote Originally Posted by thedon809 View Post
    Is that the only engine ground? If so its probably way too small.
    No. My grounds are sufficient right now. I tested them all and they all check out.

    Quote Originally Posted by tryingbe View Post
    I like 1/0 gauge, over kill it. For starter to battery, battery to alternator, and ALL ground cable.
    While that is a nice upgrade, It's not likely the cause of my problem. I ran the battery, alt in my Spirit R/T for 2 years with no issues and that had crappy stock wiring. I did just order some 2/0 welding wire though because I do want overkill on my power cables anyways.

    Quote Originally Posted by acannell View Post
    any odd possibility that the alternator electrical connections (on the alternator) are physically touching something that is ground i.e. chassis/brackets, etc.. during the high rpm acceleration/letting off gas
    That seems to be the most likely explanation for me at this time. I'm gonna start tracing wires in the ignition circuit today. Not looking forward to that.

  13. #13
    turbo addict
    Join Date
    Feb 2010
    Location
    Piedmont, Ohio
    Posts
    4,109

    Re: Electrical issues.

    What external VR are you running

    I had a very similar problem with my truck, I kept blowing fusable links and fuses, when I had enough I put a solid wire in so it wouldn't blow. After I added the big wire it would charge at 18v any time RPM's went up. I replaced the regulator (dodge 2 wire), still did it, replaced regulator connector, still did it. I finally replaced the regulator again and it fixed it. Those regulators are a crap shoot from the parts store.
    Ian Adams Function>Form 1990 shadow scrapped, too rusty:( 1991 Spirit R/T Scrapped, parts sold:( 1989 Turbo Caravan Daily beater with built-[I]ish [/I]​engine slowly evolving into weekend turbo beater.

  14. #14
    Supporting Member Turbo Mopar Contributor rx2mazda's Avatar
    Join Date
    Apr 2006
    Location
    Baltimore,MD
    Posts
    2,925

    Re: Electrical issues.

    Quote Originally Posted by shackwrrr View Post
    What external VR are you running

    I had a very similar problem with my truck, I kept blowing fusable links and fuses, when I had enough I put a solid wire in so it wouldn't blow. After I added the big wire it would charge at 18v any time RPM's went up. I replaced the regulator (dodge 2 wire), still did it, replaced regulator connector, still did it. I finally replaced the regulator again and it fixed it. Those regulators are a crap shoot from the parts store.
    Internal VR atm. Datalog showed the voltage at a steady 14.3V until it dies.

  15. #15
    Super Moderator Turbo Mopar Staff 135sohc's Avatar
    Join Date
    Aug 2008
    Location
    SoMd
    Posts
    6,178

    Re: Electrical issues.

    Quote Originally Posted by acannell View Post
    any odd possibility that the alternator electrical connections (on the alternator) are physically touching something that is ground i.e. chassis/brackets, etc.. during the high rpm acceleration/letting off gas
    Very good point. The rocking motion of the engine on mine was just enough and the positive feed from the alternator and one of the field wires were both rubbing and actually cut through that the connection was 50/50 and until I actually found it, it was very concealed and hardly evident until it was right there in view.
    1994 Shadow Sedan. 2.2 N/A, A568 400,000 miles. "the science experiment"
    1987 Shelby CSX #418. Long term rebuild and restore ?

  16. #16
    Supporting Member Turbo Mopar Contributor rx2mazda's Avatar
    Join Date
    Apr 2006
    Location
    Baltimore,MD
    Posts
    2,925

    Re: Electrical issues.

    FWIW...once the alt dies and it's running only off the battery, it can rev to 7500rpms and nothing bad happens.

Similar Threads

  1. 1991 shelby daytona electrical issues
    By mmmadog in forum "I need help!"
    Replies: 7
    Last Post: 04-10-2012, 01:06 PM
  2. Guage cluster electrical issues.
    By Stinkbox in forum "I need help!"
    Replies: 2
    Last Post: 05-31-2011, 03:00 PM
  3. Electrical issues 89 lebaron vert
    By turbo-baron in forum Electrical & Fuel System
    Replies: 0
    Last Post: 05-02-2011, 10:30 PM
  4. Electrical Issues-Pegged Volt Meter
    By 85daytona in forum "I need help!"
    Replies: 3
    Last Post: 10-27-2008, 06:42 AM
  5. Electrical issues, wont start
    By 1966 dart wagon in forum "I need help!"
    Replies: 2
    Last Post: 06-24-2008, 06:42 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •