1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Glow Plug Bypass - not working

Discussion in '6.9L IH & 7.3L IDI Diesels' started by RSchanz, Oct 24, 2020.

  1. RSchanz

    RSchanz Full Access Member

    Posts:
    69
    Likes Received:
    14
    Joined:
    Sep 29, 2020
    Location:
    Petaluma, CA
    Went to start the truck today and it wouldn't turn over. I noticed that my glow plug light wasn't turning on so I started checking around with my icepick. Wire on the left of the switch was live and the wire on the right coming out of it was not lighting up. I pressed the button while trying and nothing changed.

    I did notice an area on the wire where the insulation was worn off and looked sketchy so I'm thinking of replacing the wire regardless and at a minimum putting electrical tape over it.
    IMG_4437.jpeg

    I'm not sure what the wire attaches to but I've uploaded a picture. Can someone tell me what it is? The wire was also not appearing to be live at this spot either. This leads me to believe the button is likely not working.

    IMG_1677.jpeg

    I'm assuming it's some kind of relay with power going in on the left and when I push the button it sends power out through the wire on the right.

    IMG_4438.jpeg

    Any guidance would be appreciated!
     
  2. IDIBRONCO

    IDIBRONCO IDIBRONCO

    Posts:
    6,493
    Likes Received:
    4,733
    Joined:
    Feb 5, 2010
    Location:
    edmond, ks
    That is the glow plug relay on the 6.9 style glow plug set up. If your button doesn't work, then your glow plugs won't work since this activates them. Originally, the controller activates this relay, but people like to bypass them with a manual set up since the controllers have a habit of failing. Often it's in the "on" position which burns out your glow plugs.
    Now if your starter isn't working, it's probably not related to this relay or the button. Although there may be a fuse or fusible link that's been burned out due to the short. I ALWAYS install an inline fuse right off of the power source for manual controls. Since there's two wires in your picture, this button appears to be powered from an under hood source like the starter solenoid that's located on the passenger's fender right behind the battery.
     
    riphip likes this.
  3. RSchanz

    RSchanz Full Access Member

    Posts:
    69
    Likes Received:
    14
    Joined:
    Sep 29, 2020
    Location:
    Petaluma, CA

    Thanks for the reply. I'm aware of the issue with the factory glow plug set up. I didn't install this set up so I'm starting to work on figuring out how it goes haha.

    It's definitely linked to the starter solenoid for power. I mentioned that the wire going into the button on the left is live where the wire going out of the button on the right isn't live. This is the case whether I push the button down or not. It leads me to believe that there might be an issue within the button.
     
  4. Selahdoor

    Selahdoor How can I help you, or make you laugh, today? Supporting Member

    Posts:
    1,604
    Likes Received:
    1,180
    Joined:
    Oct 26, 2015
    Location:
    Index Wa
    Yep. Replace the button switch.
     
  5. RSchanz

    RSchanz Full Access Member

    Posts:
    69
    Likes Received:
    14
    Joined:
    Sep 29, 2020
    Location:
    Petaluma, CA

    Any good resources on where I might be able to find a switch?
     
  6. IDIBRONCO

    IDIBRONCO IDIBRONCO

    Posts:
    6,493
    Likes Received:
    4,733
    Joined:
    Feb 5, 2010
    Location:
    edmond, ks
    There's plenty of them on either Ebay or Amazon. Just type "starter push button" into the search bar. Since your button is powered from the starter solenoid, I'd recommend installing an inline fuse just in case the insulation gets rubbed off the wiring again. The most you would need is a 10 amp fuse. A 5 amp would probably do the trick as well. All you're doing is using a manual on switch for the relay. It doesn't take a lot of power to do that.
     
    chillman88, riphip and Selahdoor like this.
  7. RSchanz

    RSchanz Full Access Member

    Posts:
    69
    Likes Received:
    14
    Joined:
    Sep 29, 2020
    Location:
    Petaluma, CA
    Good call, thanks for the recommendation.

    This may sound stupid but this is the first vehicle I've owned with two batteries. Is there a certain order in which I should disconnect the batteries?
     
    Selahdoor likes this.
  8. Selahdoor

    Selahdoor How can I help you, or make you laugh, today? Supporting Member

    Posts:
    1,604
    Likes Received:
    1,180
    Joined:
    Oct 26, 2015
    Location:
    Index Wa
    Disconnect negative on driver's side battery first.

    Then negative on passenger side.

    Then both positives.
     
    riphip, RSchanz and nitroguy like this.
  9. IDIBRONCO

    IDIBRONCO IDIBRONCO

    Posts:
    6,493
    Likes Received:
    4,733
    Joined:
    Feb 5, 2010
    Location:
    edmond, ks
    This is probably the proper way to disconnect them. I honestly have no idea on the order I disconnect them. I also only disconnect all four cable ends when I'm removing the batteries. If I'm doing any type of work and need to disconnect the batteries, I'll disconnect the passenger's side negative and the driver's side positive. I do this because sometimes the driver's side negative has a tendency to fall down behind the battery and be difficult to find sometimes. As for the driver's side, to me it's easier to leave the double positive hooked to the battery. The battery is just as disconnected whether you leave the positive or the negative hooked up. Sure, you can get an arc off of the passenger's side positive this way, but I just wrap a rag or something similar around the end. You can zip tie the rag on or even wrap it in electrical tape to help hole it over the cable end.
     
  10. RSchanz

    RSchanz Full Access Member

    Posts:
    69
    Likes Received:
    14
    Joined:
    Sep 29, 2020
    Location:
    Petaluma, CA
    Any idea how or if this button should be grounded? Somehow it seems a little sketchy
     
  11. riphip

    riphip Supporting Member Supporting Member

    Posts:
    946
    Likes Received:
    347
    Joined:
    Nov 16, 2005
    Location:
    Memphis, TN.
    Grounded to frame, metal dash, etc. Use a DVOM to test.
     
  12. Selahdoor

    Selahdoor How can I help you, or make you laugh, today? Supporting Member

    Posts:
    1,604
    Likes Received:
    1,180
    Joined:
    Oct 26, 2015
    Location:
    Index Wa
    Maybe I don't really understand this question, but...

    If the button is switching power... (In other words, power comes from some source such as the fuse block, or the ignition switch... Then goes to the button... Then from the button to the solenoid...), then there is no ground involved. Ground one side of that, and you'll have major problems up to and including maybe a fire.

    If a wire comes from the solenoid, to the button, then from there, to a ground, and no power source is involved otherwise, then the question is moot, because ground is a part of the circuit.
     
  13. IDIBRONCO

    IDIBRONCO IDIBRONCO

    Posts:
    6,493
    Likes Received:
    4,733
    Joined:
    Feb 5, 2010
    Location:
    edmond, ks
    Exactly. Basically, power to switch. Then power to relay. The solenoid isn't required to heat up the 6.9 style glow plugs manually. In fact, you don't want the solenoid plugged in to the wiring harness since it could/would still send power somewhere. If it was stuck "on", then it may drain your batteries over time. When I put the 7.3 in my Blue Truck, I didn't even bother putting a 6.9 controller in the head. There's already a plug here, so it's not going to leak coolant.
     
  14. RSchanz

    RSchanz Full Access Member

    Posts:
    69
    Likes Received:
    14
    Joined:
    Sep 29, 2020
    Location:
    Petaluma, CA
    I get ya. Learning more about electricity and wiring with each project vehicle.

    Whats the alternative option for powering the glow plug harness besides using the solenoid?
     
  15. Philip1

    Philip1 Supporting Member Supporting Member

    Posts:
    314
    Likes Received:
    261
    Joined:
    Apr 1, 2019
    Location:
    Nevada
    Battery disconnect switch or similar high current manual switch.
     
    IDIBRONCO likes this.

Share This Page