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Ever swap a fuse panel?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by txbartman, Oct 1, 2001.

  1. txbartman

    txbartman 1/2 ton status

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    Alright, I had a great time wheelin' this weekend. It was my rigs first serious trip since the lift, tires, gears, hubs, everything. It did great. Now I have new pin striping and partially trimmed fenders! [​IMG] But...

    On the way home, she just died on me. Engine lost power, but still had hot to lights and some other stuff. It appears as though I lost the two right columns on the fuse panel and the hot lead out to the distributor. Well, after a couple of wire splices and a direct connect from the battery to the starter to get it hot wired, I got it home. But it sure is tough to unload all the crap from the trip through the front doors as the back window is electric!

    Anyway, to my question (finally), my guess is something inside my fuse panel went bye-bye. I plan to remove it this week and will probably end up replacing it. I have never removed a fuse panel. It looks like there are two screws (loer left, upper right). Is this all I have to remove to pull it? And do the wiring harnesses just plug in? Would I be better off to replace the original fues block with a custom one?

    What are y'all's thoughts? My baby is dead and needs some help!

    Brian
    A new day.... May God be with us all.
    <a target="_blank" href=http://tx85gmcguy.alloffroad.com>My Tribute</a>
     
  2. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    You sure it's the fuse box and not the fusible links down by the starter?
    Swapping them would not be very hard. just pull the plugs off the back of it in the engine comparment and most of it is done. Few interrior connections inside that are all plugs and it should come right out. Just wear some rubber gloves. they used a tar like sealent the stick like all get up and will for sure stain your hands till it wears off.

    I don't need no damn shop manual, I got a pornographic memory.
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  3. txbartman

    txbartman 1/2 ton status

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    Well, I think its the panel. I have a hot lead from the starter going into the panel from the engine compartment, but 2 thirds of the panel is dead on the inside. Would you agree its probably the panel?

    I traced the hot leads from the starter. I think there were three, but I traced two. One went to a switched relay for the headlights, that was hot (head lights still work). The other went into the rear of the panel, that one was still hot. I don't think I traced the third.

    Brian
    A new day.... May God be with us all.
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  4. 502Burban

    502Burban 1/2 ton status

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    There may also be another screw in the center of the fuse block that holds the two halfs together (inside/outside of firewall. It will be hidden by all the wires, so you'll need to look carefully.

    Robb
    '73 GMC Suburban - 502DFI
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  5. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    I would check that third wire first before ripping the box out. Would stink to swap the box and still have the problem. The fuse box's in out trucks are pretty solid and it would take a big short to burn one up or have to be full of water or mud to get corroded bad enough to make them fail.
    Just about Everything goes through the box at some point. With so much of the box dead and it seems to all be the IG side since your rear window isn't working. I think (not sure and don't have the diagrams to comfirm.) That the third wire may be the wire for the IG. I think it runs to the column switch then to the box. So the problem may be up in the column. Well not up, the key pushes a rod that runs down the column. the actual switch is up above the peddles on the top of the column.
    Do you have an aftermarket Alarm? Sometimes they mess with those column wires for IG and starter kill and that my be where the problem is.
    If you need a diagram hit your local Library. Most of the bigger branches will havle the Helm manuals on micro fisch and you can find your exact year. .10 cents a copy. What a bargin.

    I don't need no damn shop manual, I got a pornographic memory.
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  6. txbartman

    txbartman 1/2 ton status

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    No aftermarket alarm. Hell, don't need one right now! But that could definitely be what is up. I did a lot of jarring around this weekend. It seems as though everything that is dead is connected to either an ignition or accessory circuit. Well, except my brake lights. Anyway, I will trace that third wire tonight and see where it goes. I agree that there has to be another feed. The one hot feed I have found so far is about a 10GA wire. I find it hard to believe that everything in teh truck and engine would feed through a single 10GA wire.

    Brian
    A new day.... May God be with us all.
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  7. dyeager535

    dyeager535 1 ton status Premium Member

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    Believe your '85 will have a junction block on the firewall, towards the passenger side, about same height as brake booster. 2 or 3 red wires going to it, (from starter) leading to the fuse panel. Easy enough to check continuity from starter to the junction. I've known a few people that have either had the wires near the starter burned because of the exhaust, and a couple that had the fusible links pop. The headlights and a few other things IIRC, get their power seperately of the ignition circuit. Buy a 73-87 C/K Haynes (if you don't have one) the electrical diagrams are good enough to help you trace the wiring.

    You don't *really* want to mess with the fuse panel, as most everything coming out of it into the cab is hard wired into the panel...no unplugging. You unbolt the engine side of the harness, then the fuse panel from the wall, then ALL the wiring attached (all accessory wiring, gauge connector, etc) comes out with it. Easy enough when you have a completely stripped tub, but I would not even attempt it without pulling the guage cluster, unbolting the column, and taking off the dash pad/glove box.

    The wiring on the trucks IS good as factory, just takes some troubleshooting to find where your problem lies. Hopefully something as simple as a cut and splice on the 12v wires in the engine bay.

    Dorian
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  8. txbartman

    txbartman 1/2 ton status

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    You, Dorian, are the KING! When I got hot, I began looking under the dash first for the switched ignition circuit from on the column. I wasn't having much luck finding it. When I went into the garage to get my flashlight, I went ahead and grabbed my meter. Popped the hood and thought I would start over by tracing the wires from my starter.

    Of the three wires, one goes directly to the fuse block, one goes to the alternator plug (battery sensing alternator), and the third to a junction that hooks up to the A/C, headlights, etc. That junction is on the firewall just behind the booster. For the hell of it, I decided to meter this again (even though my headlights worked.

    Well, the lead from the starter into the connections was hot. As were the posts. But, I traced one wire that left the connection and split into two wires through an inline fused link. The wires coming out were dead. Thought it must be the fused link. As I was trying to move it to test the other side of the fused link, I noticed the wire seemed awful stretchy. I poked my test probe into the wire, but didn't find any wire! The wire had broken inside the inside the insulation! It was about a 10-12 GA stranded wire that looked more like a solid wire. Well, I put the keys in the igintion and turned it to on. Went back into the engine compartment and touched the broken wire to the post. Sure enough, hazards, blower motor, radio, buzzer, everything came on.

    So, I spliced some new wire into place, reconnected the hot on the coil (removed my hotwire connection) and reconnected the battery. She fired up good as new!

    Thanks a million, man. I am new to working electrical stuff and I was worried about trying to troubleshoot the problem.

    I know this has been a long post, but I HAD to commend you are your advice. This site has more than paid for itself in stress relief and savings in repair costs and unnecessary personal expense. I simply cannot thank you guys enough.

    Brian
    A new day.... May God be with us all.
    <a target="_blank" href=http://tx85gmcguy.alloffroad.com>My Tribute</a>
     

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