Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Try #2 Wiring Help

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by robbie, Jun 12, 2001.

  1. robbie

    robbie Registered Member

    Joined:
    Jun 8, 2001
    Posts:
    5
    Likes Received:
    0
    Hi guys,

    Nobody has a wiring layout for the bulkhead on a '87 and a earlier '80's Blazer? C'mon, *somebody* must have this! I've got one wire left that I can't figure out, and am sorting through gauges that don't work. Help!

    Robbie (putting a older harness into an '87 since I took out the EFI)
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,982
    Likes Received:
    191
    Location:
    Roy WA
    What gauge doesn't work?? There are only what, three real gauges that get input. Volts, Oil, Temp. Temp is probably green, Oil might be brown, Volts is probably red. Depending on what you need, a $13 Haynes 73-87 truck manual from teh local auto parts store has the wiring diagrams copied form the GM service manuals. Heck, find an open one at the store and just look up what you need to know.

    Dorian
    My tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
    No anti-theft measures on your truck? No pity when its stolen
     
  3. robbie

    robbie Registered Member

    Joined:
    Jun 8, 2001
    Posts:
    5
    Likes Received:
    0
    Uhhh...I'm trying to find out why the fuel, oil pressure gauges don't work. Temp does.

    I've got the Haynes good, it doesn't have the layout for bulkhead (I've got one unused wire there).

    I wouldn't expect the Haynes book to help me with putting a pre-EFI engine harness into an EFI ('87) truck, mated to a pre-80 (factory tach) gauge cluster...

    Robbie
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,982
    Likes Received:
    191
    Location:
    Roy WA
    You may just have some ground issues. Or the connectors for the wiring to cluster plug are for some reason not making contact. As well, it seems that pretty regularly, ESPECIALLY the pre '81 tach dashes, the wiring changed. Friend fried a pre '81 tach cluster trying to plug it into his '83 harness.

    You sure that Haynes doesn't list the bulkhead connector? Pretty sure thats how I figured out how to rewire my newer style delay wipers. As well, I *know* they show the fuse panel, and the bulkhead connector is an extension of that. Trace (in the manual) the headlight wiring, that runs straight to the bulkhead connector, as do the wiper wires.

    Dorian
    My tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
    No anti-theft measures on your truck? No pity when its stolen
     
  5. robbie

    robbie Registered Member

    Joined:
    Jun 8, 2001
    Posts:
    5
    Likes Received:
    0
    I'll have another look, but didn't see any bulkhead connector diagram in the Haynes book, and I went through it a couple times.

    At least, the temp and the temp gauges work. The oil pressure and the fuel act like they're grounded out - they peg out when the ignition is turned on. Gonna work on that tonight and see if it's just a bad gauge. The fuel tank sender unit isn't hooked up, so I'm surprised that it's pegging that gauge, though.

    Another reason why I was asking for the lay-out is 'cause I just have one unused wire at the "bottom" of the harness. It's pink and it's just hanging there and I have nowhere to hook it up - it wasn't part of the loom, so it's like it went back under the pick-up cab to something...ideas? It's not a light duty wire, but certainly not a heavy gage wire either...

    Robbie
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,982
    Likes Received:
    191
    Location:
    Roy WA
    Pink I believe is the fuel tank sending unit wire. I don't think the coil wire is pink, either orange or red I believe.

    Dorian
    My tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
    No anti-theft measures on your truck? No pity when its stolen
     
  7. Michael

    Michael 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,576
    Likes Received:
    0
    Location:
    Sherman, Texas
    My book shows a pink going from position 30 on the gauge cluster to position 3 on the ignition switch. Pink also goes to the "+" side of the distributor and the fuel sender.....basicly pink is the 12 volt ignition wire.

    Michael[​IMG]
    <A target="_blank" HREF=http://www.jmartin.net/parker/goose.htm>http://www.jmartin.net/parker/goose.htm</A>
     
  8. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    If you don't yet have the fuel sender hooked up, then the fuel guage is working properly. It will read Full at 90 ohms resistance in the circuit and Empty at 0 ohms. Since you don't have it connected, it's seeing infinite resistance and pegging the gauge to the Full side. Hook up the sender and you'll be all set. [​IMG]

    The oil pressure gauge may work the same way, but I'm not certain on that one.

    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://www.angelfire.com/super/ThunderTruck>http://www.angelfire.com/super/ThunderTruck</A>
    It's a great day to be alive...
     
  9. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    I just scanned in the fuse block details from the '87 factory manual. The page is too big for my scanner, so I had to break it into 2 parts. I'm uploading them to <A target="_blank" HREF=http://www.angelfire.com/super/ThunderTruck/stuff>http://www.angelfire.com/super/ThunderTruck/stuff</A>. To make it easier to look at, print them out and tape them together so they look like the single large page again. [​IMG] Enjoy!

    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://www.angelfire.com/super/ThunderTruck>http://www.angelfire.com/super/ThunderTruck</A>
    It's a great day to be alive...
     
  10. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    7,385
    Likes Received:
    0
    Location:
    Atlanta
    If you have a big library in your town they usualy have the factory manuals with good year by year diagrams in them. They are on Microfisch. 10 cents a copy.

    It's not my damn planet monkey boy!
    Grim-Reaper
     
  11. robbie

    robbie Registered Member

    Joined:
    Jun 8, 2001
    Posts:
    5
    Likes Received:
    0
    Thanks, guys!

    That figures out the fuel gauge - nothing is hooked to it right now. And I'm on top of the oil pressure gauge right now. Think I've got that one figured out too, but we'll see.

    Bonus, during all the testing, etc., looks like the tach is gonna work just fine.

    Thanks again,

    Robbie
     

Share This Page