Alternator relocation gone wrong...

Discussion in '40- & 55-Series Tech' started by S4Cruiser, Aug 24, 2009.

  1. S4Cruiser

    S4Cruiser SILVER Star

    Messages:
    1,497
    Location:
    Durham, NC
    Truck is a 74 FJ40 with a rebuilt 78 2F.

    As part of the power steering convesion on my 40 I needed to swap the alternator from the lower driver side (original 1F location) to the high passenger side (2F location) of the engine.

    This should have been a .1 :banana: job. Find the factory mount and tension adjuster, unplug alternator wires, remove alternator, mount said 2F bracket and alternator, splice orginal alternator wires and extend then so they reach the passenger side, plug wires back in and done :steer:.

    Not so much in my case.

    After I completed all steps above and tried to crank the truck it turned over 5-6 times but no start. No big deal as the carb was empty and needed to be filled with enough gas to start. So I added some choke, pumped the gas, turned the key and nothing but click, click, click.

    Pulled the 80 in the garage thinking the battery might have been dead on the 40. Tried jumping to 40 and nothing but clicks...however this time I got a little magic smoke from the ground wire (W/Blk) on the voltage regulator below the brake booster on the drivers side firewall. I didn't ruin the regulator just heated up the wire plastic cover to the point it smoked a bit.

    So what is up???

    The alternator is a OEM 3 wire. Two wires are plugged via a connector and are routed to the voltage regulator and the other connected on the back of the alternator routed directly to the positive terminal on the battery. This is the way it was connected before the move and everything worked fine.

    I don't think my starter and/or solenoid are shot b/c they were recently replaced by the PO before I bought the truck (within the past 5 years but less than 3k miles on it).

    BTW - I checked the battery and it reads 12.6 volts as it sits in the truck now.

    I'm going to clean and replace my negative terminal and frame ground and clean/replace the starter to frame ground strap tonight to rule those out.

    All advice and/or troubleshooting ideas would be awesome. Also if the way it was wired before was wrong, now is a good time to fix it since it isn't working anymore :grinpimp:.

    I've searched and read last night till my eyes were crossed but nothing jumped out and slapped me as what my problem is...just that there could be lots of problems - :censor:

    Thanks is advance!!
  2. Coolerman

    Coolerman SILVER Star

    Messages:
    4,750
    Location:
    Paint Lick, KY
    First:
    Check to be sure you have proper grounding for:
    The battery to frame
    The frame to engine
    The alternator to engine.

    Pull each end of each ground cable and clean to bare metal. Inspect the cable to make sure it's not corroded internally.
    The alternator to engine ground is normally through the mounting bracket. If you painted or powder coated the bracket or alternator it may not be getting a good ground.
  3. dargreg

    dargreg

    Messages:
    627
    Location:
    CROFTON BC CANADA
    COOLERMAN is right sounds like its takeing the closest ground it can find.
  4. S4Cruiser

    S4Cruiser SILVER Star

    Messages:
    1,497
    Location:
    Durham, NC
    Ahah :hmm: - Coolerman might have it (or at least I hope). The PO actually had the battery grounded to the engine where the front engine hook attached and I just used that point again:doh:. I did blast, epoxy prime and paint the alt bracket...so that might be my bad ground spot. I'll move that ground to the frame tonight.

    Also do you happen to have a pic of where the alt ground point on the back of the alt is supposed to be? Mine didn't have a ground wire before I moved it.
  5. Coolerman

    Coolerman SILVER Star

    Messages:
    4,750
    Location:
    Paint Lick, KY
    There is no main alternator ground, the ground occurs through the mounting ears on the alternator. On my alternator I tapped the hole in the pic below for 6mm x 1.0 and made up a 8ga jumper cable to the engine block. That way I know it's grounded well.
    IMG_1042M.jpg
  6. S4Cruiser

    S4Cruiser SILVER Star

    Messages:
    1,497
    Location:
    Durham, NC
    Gotcha - makes sense.

    Thanks!

    I hope to have this sorted tonight...darn work is getting in the way or I'd be working on it now.
  7. S4Cruiser

    S4Cruiser SILVER Star

    Messages:
    1,497
    Location:
    Durham, NC
    Car cranks and runs great after cleaning and changing the ground placements.

    Thanks MUD!

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