'97 Ford Expedition. No trailer lights. Any Ideas???

Question

1997 Ford Expedition with Factory Installed class "A" hitch package. 1st time I've had to tow anything, and I've got no power to the 7 terminal lighting connection. Fuse in under-hood main fuse box is good (slot-1, 20 Amp). Fuse in Engine Mini-Fuse box (slot 2, 20 Amp according to the owners manual) is a relay, not a fuse. Swapped with another of same type and it didn't help. Chilton's Manual and vehicle owner's manual have no information on wiring of trailer lighting connector (typical for Ford). Somebody told me Ford installs a "Dummy" fuse or relay when they install a factory hitch as a "Place Holder", and that it has to be replaced with the real thing to get power to the trailer lighting connector. Anybody out there heard about that? Any idea where it might be? Any ideas at all? Anybody wanna loan me a gun so I can eat a bullet (I'll need some A-1 sauce too, let's be real)??
Thanks in advance for any real help. -Ken

Answer 1

There is a small fuse box on the drivers side under the hood and up under the fender out of sight. It has a couple fuses in it that feed the turn signals and park lights to the trailer connector. May wish to check there.....

Answer 2

The following is assuming you are dealing with disc (front or rear) brakes. Well, the first step would be to bleed all the wheels starting with the right rear (RR) then LR, RF, LF. If you're bleeding them by yourself I'd used a small hose, that fits tight on the bleeder and is about 12 to 16 inches long, that goes into a clean bottle partially full of clean brake fluid. Don't open the bleeder more than 1/2 a turn. Make sure the end of the hose is all the way into the brake fluid, that way as you release the brake pedal on each stroke no air can get back into the system. I'd do 8 to 10 strokes each (never let the master cylinder run out of fluid). Although the master cylinder may have been damaged if it ran empty before your repair, it will usually have excessive travel before you feel any braking, not feel mushy. If your sure you have no air in the system (someone can look at the bottle as your bleeding to see if any air bubbles are still coming out of the hose) then you most likely have sticking calipers. This happens when the piston seal starts to grab onto the piston (could be for a number of different reasons) and it prevents the piston (and the pads) from moving freely to quickly grab the rotor and then stay close to the rotor (a bad seal will also pull the piston and pads away from the rotor, not giving you that solid "braking right now" feeling. You can test this by applying the brake pedal fully and then having someone clamp a brake hose with brake hose pliers/clamp. DON'T use anything else! Brake hose pliers (or clamp) has a special broad smooth surface that won't damage the hose. Release the brake pedal and apply it again. If the pedal feels hard now that's the caliper that has a problem. Redo that for each wheel. I'd suggest replacing the calipers in pairs (both front or both rear). Take a good look at the pads and rotors (I'm assuming you did this already but just incase...) If the rotors have heavy grooving, rusting or pitting within the wear area, replace the pads and rotors in pairs (as above). Also remove the pads and take a good look at the back of them; Make sure they don't have a bent or rusty shim and that the contact area between the pads and caliper piston looks clean and solid. This can be a problem for phenolic (non-metallic) caliper pistons. Ok, time for me to stop talking :)

Answer 3

Check for blown fuses in fuse box.. each side of the trailer has their own fuse (for tuen and brakes)

the trailer wiring conncector in back has what wires where on the cover itself if it was installed from Ford.. watch out as it's easy to put everything back there and look factory (did it so many times it ain't funny)

I do know there were some relays you sometimes had to put for 7 pin trailer towing on some of them (I think to feed 12v all the time and reverse .. most of the turn signal/brake, ground, and run lamps share the same circuits as the 4 pin connector (If there is one).. But If I also remember, everything had a relay on that model...

Also Ford never installs dummy relays, they just don't install them. It leaves it in the bag with the trailer brake controller wiring pigtail when it leaves the factory.

Answer 4

Take it to the dealership and have them fix they're mess. If it was a factory installed hitch then it should be working properly when it leaves the dealership, if not they screwed up the wiring somewhere. No there's no "dummy" fuse installed in the vehicle anywhere its just a lie.

Answer 5

there is a little fuse on the side of the break master cylinder under a black cover.
if i remember correcty it is the second from the end and it is a 15 amp fuse.

Answer 6

check for continuity...could be a wiring prob.