6.2 Glow Plug Controller

Discussion in '6.2 GM Diesels' started by crowswagon, Jun 19, 2012.

  1. crowswagon

    crowswagon New Member

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    Hi All,
    I replaced the Glow Plug Controller about 8 months ago with an AC Delco that I bought on ebay... The truck ran fine with no problems till last week. Glow plug light does not come on any more.
    I turn the key, no glow plug light... only the momentary: water in fuel light, which is normal. The engine cranks normal, but will not start. There is no Glow Plug Inhibit Switch located on top of the engine block, so I don't think there is one.
    Is this just a bad controller, or do I need to check something else?
    Thanks...



    1988 Chevy Crew Cab with the 6.2
     
  2. NVW

    NVW Active Member

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  3. ak diesel driver

    ak diesel driver Active Member

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  4. just a number

    just a number Active Member

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    the large wire(IIRC it's pink) should have 12V key on. the inhibit switch is on the passenger side head right at the back. I know the orange wire goes to the dash light.

    does the controller make any noises?

    have you confirmed 12V at the studs?

    I'll see what I can dig up for ya.
     
  5. crowswagon

    crowswagon New Member

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    Thanks, here's what I've got so far...
    There is no Inhibit Switch mounted on the top of the head, only a delete plate where it should be, unless it is mounted elsewhere..?

    The connector on the controller has 4 wires to the 4 pins, BCD and E. Pin C, I thought, was for the inhibit switch, I don't know what C is connected to.

    The controller clicks once when the key is turned to the on position.

    The controller has about a half inch crack in the case at the battery stud.

    I'll test the controller and glow plugs with an ammeter in the morning...
     
  6. crowswagon

    crowswagon New Member

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    Just an update,
    Went through the troubleshooting checklist in the Haynes manual,
    fuse, glow plugs, batteries, controller all checked out with key in the off position, kept getting
    some funky voltage readings with ignition on... went back through all the battery connections, found that the battery cable to the starter had melted insulation and had welded itself to the heat shield below the starter...one new cable, all systems checked out, truck runs good as new...
    Thanks for all the help,
    Warne
     
  7. just a number

    just a number Active Member

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    gm went el cheapo when it came to wiring. most of it is undersized. what gauge did you put in for a new cable?

    the inhibit switch is down beside the injector.
     
    Last edited: Jun 23, 2012
  8. crowswagon

    crowswagon New Member

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    I just picked up a 4 gauge cable from the local auto parts store..
    Do I need something heavier?

    Ok was looking elsewhere for the switch...
    Thanks
     
  9. just a number

    just a number Active Member

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    the winter months you'll want to be heavier than that. IIRC stock is 2 gauge. 4 will hold for the summer. how's the rest of the cables look?

    which starter are you using the 27(direct drive,older design) or the 28(gear reduction)? it does make a difference of how big of cable you need.

    the nice cables are alot bigger.
     
  10. crowswagon

    crowswagon New Member

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    All the cables are 4 gauge, good condition... maybe about 3 years old...

    Do I need to look at replacing all the wiring in the truck, or just the heavy duty wires?

    What do I look for on the starter..?, it's a rebuilt from Advance Auto... replaced about the same time as the cables.
    Thanks
     
  11. just a number

    just a number Active Member

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    if the cables are in good shape leave them till you start to have issues. you only need to change the heavy set.

    the differences to look at the starter is the 27(older) housing is about 4" across and is straight with the nose cone. the 28 is small across and offset to the nose. I think its higher than the nose when mounted.

    one more note on starters, make sure the front bracket is on there. they have a tendency to cause problems is you don't.

    hows the winter starting on it?

    a bit off topic but have you done the bolt mod yet? it's worth the time and effort.
    http://www.thetruckstop.us/forum/showthread.php?540-Sticky-Candidate-Battery-Connections
     
  12. iamdave0887

    iamdave0887 Here Comes Chaos.....

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    I'd go much bigger than 4 gauge. I'm running 1/0 gauge cables for the battery crossover and both grounds, and 2/0 gauge to my starter. The engine might as well do a flip when starting, even in the dead of winter.

    4 gauge will end up melting on you if you have to crank the engine for any length of time.

    Find yourself a local auto-electric shop. They can make you some heavy duty battery cables of you don't have the time to make them yourself.
     
  13. crowswagon

    crowswagon New Member

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    Thanks for the info on the starter, I'll have to check the front bracket, don't remember if I hooked it up or not.
    Winter starts take a while if it is left out for any length of time... if I can, on real cold days, I make sure to start it every couple hours... I keep the block heater plugged in at home, starts right up with the heater. If it is below -10, I try not to park it for any length of time with out the block heater.
    I did the bolt mod when I replaced the battery cables, there was an improvement.
     
  14. crowswagon

    crowswagon New Member

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    Thanks, I will look into getting new cables for the winter, I didn't realize they made that much of a difference... I know when I replaced the originals with 4 gauge, there was a noticeable improvement.
     
  15. crowswagon

    crowswagon New Member

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    Is there enough room for the large cables to connect to the side mounts, especially the drivers side? There isn't a lot of room between the battery and radiator on that side, I only did the bolt mod on the passenger side battery...
     
  16. just a number

    just a number Active Member

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    check out the set from 'pt wiring solutions'. he's a vendor on here and make ones for the 6.2/6.5. it's worth a look.

    iamdave is right, the bigger cables make a huge difference. I had a set of 2/0 for the truck made up(local shop) and haven't had half the starting problems that I used to. I used to heat/melt 1ga cable along with a few ends.

    BTW a good set of batteries and cables they'll start at -20F without alot of issues. and that's without the block heater
     
  17. iamdave0887

    iamdave0887 Here Comes Chaos.....

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    There's room. I"ve got pictures somewhere of my cables but i can't find them at the moment.

    What i did was a took solid copper ring terminals made for my gauge wire and crimped them with a vise onto the wires. Once that was done i took a punch and indented the crimp a bit to give it even more of a bite. Then i took weatherproof heat shrink tubing(this stuff contains a glue to seal the inside connection from the outside elements and works great!) and sealed the entire wire connection on both the cable side and the copper lug side.

    it's been close to 2 years with this setup and they are just as good as the day i installed them.

    The only thing i can recommend would be to ditch the sidepost batteries next ot you replace them. Heavy cables tend to pull on the pressed in threaded steel insert and make it loose in the lead. Instead of the 78s, get a set of 34s. They are the same dimensions as the 78 except for being top post. Then you can get "top to side post" conversion terminals and just bolt the cables to them. This way if one of the conversion terminals strips out, ou can just get a new conversion terminal, instead of a new batttery.

    That's how mine are set up, and it works like a charm.
     

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