2014 Lincoln MKZ Hybrid -- LED Light Issue?

[RWP]

Bought a new 2014 MKZ hybrid about two weeks ago after learning here (and confirming with Lincoln) that it can be flat-towed. Lincoln says the 2014 cars are exactly the same as 2013, and Blue Ox says its base plate for the 2013 model will carry over to the '14s. BUT Blue Ox says that so far their engineers have not figured out a way to wire the LED lights to work with the coach lights. (The coach already has a Blue Ox tow bar and Air Force One braking system, which we used withe our previous car.) The parts person I spoke with at Lazy Days in FL seemed unaware of a potential problem, stating that diodes would do the trick. The guy at Blue Ox says diodes won't work with the type of wiring used for LEDs. The only light option may be those ugly magentic mounted ones. Sure would hate to go that route. The Bllue Ox fellow predicts a solution will be found in time, as more and more car manufacturers are going with all-LED lighting. Does anyone here know if there's a way to make the car's LED lights work with the coach lights? Thanks!

[jrwitt]

I don't know anything about the LED lights, but have you considered putting separate bulbs into the existing light housings? If there is room for the additional bulb, this would allow you to connect the lights without touching the car's LED system. Roadmaster makes a kit for this and I suspect Blue Ox does as well.

[ditto]

I used a light bar with suction cups and strap ...ran light wire from grill to rear bumper...because of the LEDs ...I stayed away from the cars electrical system.

[Wayne M]

On my '07 Saturn I didn't have LED's but I still opted to go with the separate light bulbs. Demco makes a light set and that was the bar I had a the time. I hole is drilled in each tail light section and sockets are installed to accept the tail light bulbs. the wiring is independent of the wiring on the car. The coach lighting system controls the lights. For the brake, AF1 pulls the brake pedal to apply brake pressure and in doing so causes the brake light switch to activate. That should take care of the braking (check on that one, please.)

On my 2013 Lincoln MKX I had the Diode system installed. It works fine and I believe they are LED's in the tail light section. Don't know that for sure.

[Pusherman]

Yep, the LED tail lights in SOME new cars use a digital pulsing system to make the lights operate, which means they aren't getting a traditional 12V source to make them operate. They use 1 wire to illuminate both stop/turn and tail lights. Therefore diodes will not work.

The separate bulb route will work, as it totally isolates the car wiring from the coach wiring. Blue Ox also makes 12V LED bulb/sockets which are smaller than the incandescent ones, which may better fit into your OEM tail light housing. The Blue Ox guy should have told you that, as it's their product. I don't know if they will fit in your OEM housing, but it's a better route than the larger incandescent 2-filament bulb.

In cars with the digital pulsing system with LED tail lights, separate bulb kits are the only way to make stop/turn/tail lighting work in your OEM housing. Otherwise, you will need to use external lights, such as light bars, etc.

[Wayne M]

Don,

Thanks for the clarification. I'm going to see if one of the little men running around inside my head can file the digital pulsing system with LED lights for future use.

[Pusherman]

For us techno-geeks the proper technical term is most likely 'pulse-width-modulation (PWM)' or 'pulse-code-modulation (PCM)'. This technology is used a lot to send multiple signals along one signal wire. If it is a digital system with 8 bits of digital signal codes, you can do 256 things on the same wire. Same technology used in 'fly-by-wire' systems (you guys are now seeing my prior life coming out as a digital imaging guy).

Bottom line is cars can lower the cost of wiring harnesses by simplifying wiring, using this PWM technology to signal what-ever, in this case, the tail lights to signal stop/tail/turn. And the voltage levels are probably around 4-8V -- thus the reason our old stand-by diodes won't work.

Wayne -- we found this out the hard way -- wiring up LED tail lights on the new Explorers.

Again, if there's room in the tail light assembly on these vehicles, use Blue Ox's separate LED bulb kits which isolate the car wiring from the motorhome wiring.

[Wayne M]

Hmmm! I wonder what my 2013 Lincoln MkX has. It is using the diodes - so the installer said.

[Gormleys]

I just had the Brake Buddy Stealth installed into my '13 Lincoln MKZ. I think they went the diode route for making the lights work. I've only towed it from CW to home and the lights still work.

[RWP]

Just had the Blue Ox and Air Force One tow package installed on the 2014 MKZ hybrid. The job was done at Lazy Days in Florida. We had quite a discussion about the LED light issue. A light kit supplied by Blue Ox can bypass the car's electrical system altogether, probably a good option with a brand new car and the desire to avoid any potential warranty issues. However, the Blue Ox package requires drilling into the existing brake light housing in order to insert an LED bulb. There wasn't room for this in the MKZ tail light assembly. Both Lazy Days and I then called Blue Ox separately, who continued to insist that the diode system usually used to tie the car's brake lights to the coach would NOT work...and the only solution was a light bar of some sort on the trunk. Ugly, ugly, ugly -- and almost certain to scratch the finish of the new car. However, the Lazy Days tech was all but certain that the diode approach would work, Ford's sophisticated wiring system notwithstanding. Of course it was my call -- and i decided to go with the tech's experience -- and as I watched he made the fateful cut into the Lincoln wiring. He didn't cut the harness, of course, just at the tail light itself, behind the connector that hooked the tail light assembly to the main wiring harness. In the worst case, I would have had to buy a new tail light assembly...certainly not cheap...but in his view, a highly unlikely outcome. Botttom line: the diodes worked like a charm! The car lights work exactly as they should -- when the car is being towed and not. So chalk one up for Lazy Days! I will be calling Blue Ox to report my experience and encourage them to provide updated information to anyone with concerns about towing a Lincoln MKZ hybrid...and, I would assume, a similar Ford Fusion. I felt i should report the final results to this group to alleviate any lingering questions or concerns. This is a great forum. Thanks to all who provide so much outstanding information.

[JohnRR]

Thank you for the update, the information is appreciated.

[Wayne M]

I'm about 1000 miles into towing the 2013 Lincoln MKX using the diodes and all is well.

[RWP]

Called Blue Ox today with my story, and they still insist the diodes are a bad idea on the 2013/14 MKZ hybrid. Without giving specifics, they said there are instances where, some time after installation, the diode mod sends error signals to the car computer and can screw things up. Reporting back in the interest of full disclosure. Time will tell the tale!

[Wayne M]

I wonder what the difference between the MKZ and MKX lighting systems are.