1. Welcome to PlowSite. Notice a fresh look and new features? It’s now easier to share photos and videos, find popular topics fast, and enjoy expanded user profiles. If you have any questions, click HELP at the top or bottom of any page, or send an email to help@plowsite.com. We welcome your feedback.

    Dismiss Notice

Cat 247B Glow Plugs - Need help

Discussion in 'Truck & Equipment Repair' started by Snakeman, Apr 13, 2009.

  1. Snakeman

    Snakeman Junior Member
    Messages: 12

    My Cat 247B started to not start when I pushed the glow plug button in. Cranks, and white smoke comes out the exhaust.
    OK, looks like the glow plugs are not working.

    I traced it, and found the glow plug relay was bad. I replaced it, and got one good start before it blew the relay again.
    The way Cat has them wired, all of the plugs are on a common rail, with the wire from the relay on one end.

    I pulled all the glow plugs out (4), and they all look physically good.
    So I put a ohm meter on each one, and they had continuity from the wire attachment point to the body.
    To me, I think they are shorted. They are $38.00 each, and another $24.00 for the relay. I don't want to throw money I don't have at it, guessing.

    So, how does one check the plugs to make sure they are bad?

    Thanks in advance, Snakeman
  2. Snakeman

    Snakeman Junior Member
    Messages: 12

    Since I got no reply, I Googled testing glow plugs this morning, and found a surefire way to test them, using a battery charger.
    The web sight is in the UK, and they have alot of diesels over there, so I thought, what the hell, and tried it, and one was bad. Shorted


    I also found a method of using a test light to check them, and that way showed the bad one to be good. Same with a ohms meter, showed it to be good.

    Thought I'd share this for others to use.