78 Camaro Fuse Block Troubles

Discussion in 'Troubleshooting & Diagnosis' started by PFZ28, Jun 14, 2017.

  1. PFZ28

    PFZ28 Veteran Member

    Messages:
    473
    Likes Received:
    7
    Joined:
    Dec 6, 2009
    Location:
    ThornTown, Colorado
    Hi all, I've run into some electrical trouble with my 78 Z, hoping you can help me. At the fuse block, I get no power at the IGN. (Ignition) port, and power all the time at the ACC. (Accessory) port, no matter what position the key is in. The BAT. port seems to operate correctly, with power when the key is at Run.

    Oddly, this started with a heater core replacement, which you all know, is about like parting out the car.

    [​IMG]Untitled by pfz28, on Flickr

    Well it was only a couple more steps to put in a different dashboard so I did that too. When I got everything back together, the motor would crank, but not start. Very odd, considering that my LS swap has been nothing but reliable since I put it in last summer.

    Through troubleshooting (and some level of panic), I determined that, since there's no power coming from the IGN port, the engine computer never notices it's supposed to start. Once I give it some power from somewhere, the LS roars to life when the key is twisted. Whew! No problems on the LS front.

    Starter: Working
    Headlights: Working
    Wipers: Working
    Heater: Working
    Gauge Lights: Working

    Power Windows: Not working
    Gauges: Not working - gauges don't "Wake up" when the key turns on

    Radio: Not checked - currently removed
    Courtesy lamps: Not checked - they're all burned out


    Short version of the story: With the steering column down, I test the ignition switch on top of the column, and get the following results:

    Big Red Wires: Hot all the time
    Big Orange Wire: Hot in RUN
    Big Brown Wire: Hot all the time (Seems odd)
    Big Pink Wire: Hot in RUN and START
    Big Purple Wire: Hot in START

    So ignition switch seems to be okay at first glance, with an oddity at the big brown wire.

    Testing the fuse block, I get the following results:

    ACC.: Hot all the time (Seems odd)
    IGN.: Never hot
    BAT.: Hot in RUN
    Fuses: all checked visually, no breaks

    Trying to think what I might have done during the heater core or dashboard replacement to cause such a weird problem. At first, I thought it would be easy, I'd obviously left something disconnected. Well now it's been a week and I can't find anything.

    I guess next step is to pull off the fuse block? I don't even know how to start on that.

    Any help would be appreciated!! :)
     
  2. PFZ28

    PFZ28 Veteran Member

    Messages:
    473
    Likes Received:
    7
    Joined:
    Dec 6, 2009
    Location:
    ThornTown, Colorado
    Here's a shot of the fuse block.

    [​IMG]Untitled by pfz28, on Flickr

    After I uploaded this pic, I noticed there's a blank thing at the top. Did I knock out a circuit breaker or something there? That's the kind of dumb-guy thing I'm looking for...
     
  3. PFZ28

    PFZ28 Veteran Member

    Messages:
    473
    Likes Received:
    7
    Joined:
    Dec 6, 2009
    Location:
    ThornTown, Colorado
    So, I got everything solved and the car is running fine again. Just to close the loop here, I found two issues: First, I thought all the fuses were good, but they weren't. The Gauges fuse was popped. This fuse, I finally discovered, also controls the ACC. port. So, once I found the bad fuse and replaced it, things were almost all better...

    The second issue was the power windows. Unfortunately I don't know what happened with them. It's possible that I bonked the window relay (bolted to the steering shaft) which broke the solder joint between the relay and the case (which is its ground). I was messing with the plug while the relay was still bolted to the steering column, and pulled the relay apart. Once visually inspected, I reassembled the relay, soldered the ground, bolted it back on the car, and it worked.
     
  4. Walter C Hlass Jr

    Walter C Hlass Jr New Member

    Messages:
    2
    Likes Received:
    0
    Joined:
    Jun 4, 2018
    Location:
    Lake California
    My Camaro
    1978 LT has a turn column that you can shift gears, and also came with a floor shifter. It was a option that they came out with in 1978 when I bought it new. Well I put a new OEM steering wheel column in and I have no power to the fuse box?
    I replaced the motor and transmission 350 High Performance. Everything worked before I put the new steering column in. No power to fuse box. Have power to all under hood wiring. The last column the stock one I had to unhook the shifter on the tilt wheel, and cut the switch arm, so the car would start with new ground up rebuilding. I’m stuck I have tried everything in my power to get juice to fuse box. If I take a hot wire and touch the purple wire it turns over. I’m at a loss. Coming down to just getting the power to fuse panel. Then I can finish the car up. Been working on it sense 2017 Help!!!!
     
  5. berg2695

    berg2695 Veteran Member

    Messages:
    575
    Likes Received:
    213
    Joined:
    Nov 13, 2011
    Location:
    Auburn, WA
    Welcome Walter! There is a big red 10 gauge wire that goes to the fuse box connector in the engine compartment. I would check for voltage there and work backwards towards the battery. There should be a fusible link on the fuse box end of that red wire. It may be blown. It has extra thick insulation, so it may or may not look burned. Good luck and we'd love to see some pics of your project.
     
  6. wcglass

    wcglass New Member

    Messages:
    4
    Likes Received:
    0
    Joined:
    Jun 6, 2021
    Location:
    Lake California
    What is the big brownish pinkest wire that comes from the fuse box that wire goes into the engine bay. There are three red wires that are hooked together one goes to alternator plug the other one goes to AC I was wondering if the other red wire might be the one that goes to the brownish one?
     
  7. Walter C Hlass Jr

    Walter C Hlass Jr New Member

    Messages:
    2
    Likes Received:
    0
    Joined:
    Jun 4, 2018
    Location:
    Lake California
     
  8. wcglass

    wcglass New Member

    Messages:
    4
    Likes Received:
    0
    Joined:
    Jun 6, 2021
    Location:
    Lake California
    How do you use a voltage wire tester?
     
  9. wcglass

    wcglass New Member

    Messages:
    4
    Likes Received:
    0
    Joined:
    Jun 6, 2021
    Location:
    Lake California
     
  10. wcglass

    wcglass New Member

    Messages:
    4
    Likes Received:
    0
    Joined:
    Jun 6, 2021
    Location:
    Lake California
    I took my fuse box apart and found the issue, in my rebuilding of Camaro LT super Sport 1978
    I don’t get how to put the fuse box back together, it’s in two pieces. There are clips on the side and a black octagon plastic plug. Does the separate the fuse box two pieces not to touch each other? ‘Help please.
    Walter Glass
     

Share This Page