Forum Discussion

deprived's avatar
deprived
Explorer
Oct 14, 2016

Tow-light problems: 2007 Ford E450

We have a 2007 Fleetwood Jamboree on a Ford E-450 chassis. We tow a Honda CRV that's hooked up to the Ford via a standard 7-pin to 4-pin pigtail and diode harness from eTrailer.

Things have been working just fine: brake lights, running lights and turn-signal voltage from the motorhome to the Honda have been optimal.

Today, I noticed that the the turn-signal and brakes from the motorhome is not lighting up the turn-signals on the Honda. The running lights, yes, but not the turn signal or brakes.

Initially, I suspected the diode harness from eTrailer, but a quick check with both a test-light and a VOM surprised me.


I checked volts at the where the pig-tail hooks in to the Honda and, no volts. No brake-light from from the motorhome and no turn-signal volts. Wow.

For some reason the motorhome has stopped sending volts (with the exception of the running lights) to the 7-blade connector on the motorhome for braking and turn signals. The 7-blade connector is essentially and new was replaced about three months ago. It worked just fine then.

Is there some fuse I should be looking for? Maybe something in-line?

My Ford E-450 manual seems to have a fuse (#38, I think) that protects an electric tow-brake circuit but not much else. That fuse is good. Is there some other fuse?

When I get to a decent campground, I'll look at the wiring diagram from Fleetwood, but until then, do any of you smarty-pants have some ideas? I'm not seeing the logic of this problem.

If my motorhome brake & turn lights work, why does my tow-light harness not work? Very confusing.

As always, thanks to the community.
  • j-d's avatar
    j-d
    Explorer II
    It's possible the extra bulbs on the Fit overloaded the fuses on the Trailer circuits of the E450. They have fuses for their chassis lamps, and separate ones for Trailer. Coach builders are not consistent in which circuit they use for what. It's apparently easier to connect the coach body's lights (Stop, Tail, Turn, Running) to Trailer than to Chassis.
  • Ground Ground Ground and spray some WD 40 on both sides of the connections