Forum Discussion

pcantin's avatar
pcantin
Explorer
Jul 15, 2013

Marker (Clearance) Light Issues

Hi there.

I have a 1989 Ford class C. It is the Glendale Sterling series built on an E350 frame.

The last time I checked, all the lights on the vehicle worked (I just had it certified in the fall). After bringing it home from storage, the upper marker lights on the front and back are not working. The lower lights on the bumper work fine.

I checked all the fuses in the cab, but all were fine. Is there possibly another fuse box somewhere that holds a fuse for the upper lights?

It has the 460 gas engine in it in case that is important information.

Thanks for the help!
Class C
  • Hank85713's avatar
    Hank85713
    Explorer
    Jul 16, 2013
    actually check the ground connection to the frame/engine to see if it is corroded. This will be easier than trying to go to each light. should be a grand strap that you can find, another way is to run as above to the ground at 1 light and see if the rest work. seeing you are in Canada with snow etc bet its the frame ground.
  • pcantin's avatar
    pcantin
    Explorer
    Jul 15, 2013
    enblethen wrote:
    No, the lights are not in series. They are in parallel.


    I thought that to be the case, but after seeing how these things are put together, nothing would surprise me!!!
  • pcantin's avatar
    pcantin
    Explorer
    Jul 15, 2013
    Ozlander wrote:
    Try a new light bulb.


    Are the lights in series (one burn out means the whole circuit goes dead)?

    I will take a look to see if all the wires are connected and go from there.

    Thanks again for all the suggestions.
  • enblethen's avatar
    enblethen
    Nomad
    Jul 15, 2013
    Skin being fiberglass makes it a little harder to locate.
    Try running a jumper from ground to a fixture ground point. This will tell if it is a ground broken.
    If the ground does not show being open, do the same thing by applying 12 volts DC to the center point of the lamp to see if lights come on.
    Wiring could be run either up the rrear near one of the tailights, or in the front near where the chassis(cab) meets the coach. Could be corroded or broken wire.
  • pcantin's avatar
    pcantin
    Explorer
    Jul 15, 2013
    Darn! A fuse would have been MUCH easier!!

    The skin on my rig is fiberglass, but there is a metal framework. I will have to look a little deeper to see where it grounds.

    Thanks for the (unfortunate) information. If anyone out there has the same rig, and they know where the lights ground, please let me know!

    Peter
  • wittmeba's avatar
    wittmeba
    Explorer
    Jul 15, 2013
    Sounds to me like a broken wire/bad connection before the first lamp in the string for the upper set. Not sure how to troubleshoot but start at the front lamp and check for good connections.
  • enblethen's avatar
    enblethen
    Nomad
    Jul 15, 2013
    Some have fuses in small panel behind the driver's seat.
    I would guess that itis not a fuse but a bad ground. You could locate the main upper fixture where the ground attaches to the skin of the rig. Metal sheathed rigs use the skin as a ground path, each fixture has a mounting screw that connects the fixture to ground.
    Try running a temporary wire from a good ground and touch the shell of one of the lamps in a fixture that is in-operative. If it lights then it is a ground problem.

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