Modify FLEX LED Tail Light Assembly

[O HENRY]

I have been studying adding an additional tail/turn/stop bulb in my FLEX tail lights. The purpose is for a lamps powered by the towing RV's power, brakes and turn signals, separate from the Flex wiring. I will have Factory LED's in the LIMITED. Has anyone done this? Is there space for adding a bulb in each tail light assembly, top or bottom, and any suggestions? The added lamps do not have to be LED's. Henry

 

 

[theoldwizard]

I have been studying adding an additional tail/turn/stop bulb in my FLEX tail lights. The purpose is for a lamps powered by the towing RV's power, brakes and turn signals, separate from the Flex wiring. I will have Factory LED's in the LIMITED. Has anyone done this? Is there space for adding a bulb in each tail light assembly, top or bottom, and any suggestions? The added lamps do not have to be LED's. Henry

Great idea !

 

I'm not certain if a single "high powered" LED would provide adequate light to pass motor vehicle inspection. A standard single filament bulb (1156/3156 -backup lights) puts out 275-500 lumens. A dual filament bub (1157/3157 - running/stop/turn) puts out 20-40 lumens running and 275-500 stop/turn.

 

Check this web site Super Bright LEDs

 

Last thought. If you are good with wiring, you could "splice" an auxiliary harness into the running/stop/turn harness. If you do this, I strongly suggest some relays to prevent the tow vehicle from powering up the rest of the harness and switching to LED bulbs to lessen the electrical load on the towing vehicle.

Edited March 28, 2011 by theoldwizard

[O HENRY]

theoldwizard

 

Thanks for your comments. Today I took delivery of Flex and remover 2 screws at tail light with rear hatch open and looked behind assembly and took pictures. Pictures are attached. After I complete my thoughts into words I will Post comments probably in several posts (Problems, Possible solutions, and my thoughts of best solution for me and the Limited Flex with my RV. Comments are sought. Thanks again. Henry

[O HENRY]

Problems and Facts as believed:

 

Problem: Plan a simply wiring solution that does not include relays, diodes spliced into Flex circuits, & added Flex power wiring while keeping, untapped Flex Limited LED tail lights and Flex conventional backup lights.

 

Facts as I see them:

 

1. My RV as towing vehicle has existing separate relays, fuses, flasher and wiring to 7 pin connector dedicated for towed vehicle (Toad) for a conventional dual contact bulb like 1157 bayonet base or 3157 wedge type base Tail/brake/turn signal lamp. One bulb in each side of toad needs to be added showing RED. Possibly wire to RV tail lights or a ballast may be needed in left and right Stop/Turn circuits if LED bulbs are used in Toad, to let RV flasher have enough load to flash properly.

 

2. Wiring from a front receptacle at bottom of Flex grill, under bumper to under Flex and up to each tail light is easy. It avoids splices into Flex wiring under hood and/or under dash.

 

3. Flex Limited has LED's that are different from SE and SEL as seen in Owner's Manual "Replacing ..." & "Bulb Replacement". LED's are not owner replaceable but by Dealer. The back side of assembly is sealed with one cable entrance for top and lower section LED's. With engine off, key in Accessory Position, as required for towing, as braking unit presses the brake pedal, many brake LED's light up. Power from or to brake switch I think should not be risk to always properly cut off an added relay. Voltage from brakes feeds to a very expensive smart junction box, as per wiring diagram. The backup lamp is removable by owner from the back side for replacement.

 

4. LED's are long life, use many small LED's together, use less power for equivalent brightness. Lumens of conventional and LED's are not related to wattage. See Notes Concerning Conversion to LED Car Bulbs. http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fcarbulb-notes.htm

 

5. All 2011 Flex's have the same Backup bulb, a conventional clear #194, 18 watt, 12.4 V bulb behind a clear lens in the middle smaller section of the tail light assembly. It is installed with smaller that convention 1157 higher wattage, twist out socket. The clear #194 lights in all directions and is reflected out, thus if cut in to mounted in the top part of reflector, as seen on the back side, should be OK and will fit the space.

 

6. If in the small backup section a cooler that #194, a cooler and brighter than conventional 3157 or 1157, but RED, LED, is installed where the original backup light was, the reflector should do a good job as RV powered Tail/brake/turn signal lamp. The socket is some larger, but could be cut in and caulked for seal. Behind the assembly, space for the larger socket appears to exist. The RED LED selection of angle of lighting would not be as important placed where the reflector is designed to do its best.

 

7. Could add a new circuit and relay to power 1 or 2 small, backup lights mounted under rear bumper, using 55 watt fog lights. See http://www.pilotautomotive.com/Product.aspx?ProductID=27126

 

 

[O HENRY]

Possible Solutions:

 

A. Use Blue Ox Bulb & Socket Tail Light Kit as per http://www.blueox.us/PDFS/BX8869.PDF or similar auto parts not connected to Toad wiring. Relocate original backup bulb as discussed in 6. above. Install new RED LED, RV powered bulb where original backup lamp was.

 

B. Use one of many Diode Kits offered by Roadmaster, Blue Ox and others. Blue Ox has a 9 connection Diode that would probably work, but where to put it and wiring is a challenge for the Flex. Kit for various vehicles are seen at http://www.blueox.us/Accessories/wiring.htm

 

C. Use hitch mounted light bar as seen with above link as is recommended by Blue Ox with their Base Plate for the Limited Flex because of the LED tail lights. Or mount at each towing suction cups, straps etc or magnet base lights, light bars etc. Work to install, remove, store and remount each time solutions.

 

Discussion is welcomed, before selecting the "Best Possible Solution"

 

 

 

 

[jcthorne]

You need to get the Ford Electrical troubleshooting manual and look at the circuits.

 

Your Flex limited LED tail lamps are similar to those in our MKT that we just set up for being towed behind our RV. Very simple hookup, plug in, all in the engine bay at the smart junction box. The factory includes 3 relays in the trailer tow circuits. Connecting left and right turn and running lights to pin 2 of the relays via a simple diode allows the RV to drive the relay and power the LEDs and all running lamps. Even the high mounted center stop lamp across the tail gate works normally.

 

No bulb sockets need to be installed, no wiring to the rear of the car. 3 diodes, 4 connections, no splices or cut wires, no interference between the vehicles and no load troubles for the RV (our RV is also a Ford chassis and has the factory trailer tow relays to power the trailer lights and battery charge circuit which you will need for the brake system)

[O HENRY]

You need to get the Ford Electrical troubleshooting manual and look at the circuits.

 

Your Flex limited LED tail lamps are similar to those in our MKT that we just set up for being towed behind our RV. Very simple hookup, plug in, all in the engine bay at the smart junction box. The factory includes 3 relays in the trailer tow circuits. Connecting left and right turn and running lights to pin 2 of the relays via a simple diode allows the RV to drive the relay and power the LEDs and all running lamps. Even the high mounted center stop lamp across the tail gate works normally.

 

No bulb sockets need to be installed, no wiring to the rear of the car. 3 diodes, 4 connections, no splices or cut wires, no interference between the vehicles and no load troubles for the RV (our RV is also a Ford chassis and has the factory trailer tow relays to power the trailer lights and battery charge circuit which you will need for the brake system)

[O HENRY]

Thank You jcthorne for sharing your recent experience of fixing your MKT for towing. Your Suggestion I consider Possible Solution D. I will research it with my Flex. Just last night I planned to again remove a tail light assembly and this time open it with a special tool, if I had one to inserted into a 1/4" nut driver. Just before doing so, I checked E-Mails and your Reply was there. Thanks again as it was just in time. Sharing is what the Forum is about.

Who wired your MKT? Did you do it yourself? I would like to talk with them or you. In my next Reply to the Forum, I will included for all some more questions and copy you with a PM. The more experiences involved the better. Other can also benefit from our Replies. I have ask that you allow me to have you as a Friend and see that approval. Thanks!

 

You might desired to do a test of your system setup: Drive the MKT up behind the RV. Connect the power cord. In the MKT fix switches for towing, headlights off, ignition to accessory. Turn RV park lights on. Check MKT tail lights to be on. Two people are needed: One to push RV then next only the MKT brake pedals and the other person watch MKT brake lights. Do the MKT brake lights come on both times? I think they might unless the MKT also has an added under dash Brake Relay.

 

Now three people are required to push both RV and MKT brake petals (Like stopping with the Brake Buddy) and the 3rd person watch MKT tail for brake lights. Now with both brakes pushed, try left and right RV Turn signals. Question the person behind the MKT if the turn signal lights flashed properly? If you do these test, please let me know the results.

 

Henry

[O HENRY]

I like to have the Flex wired for towing, so all electrically for rear lights; the only thing I do before towing is connect the 7 wire male plug to female receptacle at the Flex grill.

 

If the FLEX and MKT are the same I can't make this work in my mind. Looking at Flex Wiring Diagram of the AUXILIARY RELAY BOX for Trailer Tow, 3 Pins #2 Page 95-1, I can't relate it to solving my Problem. If diodes are placed to prevent RV 12 VDC applied to Pins #2, from back feeding to (SJB) SMART JUNCTION BOX, to me then the 3 relays close contacts to permit only FLEX powered brake lights to feed FLEX TRAILER CONNECTORS that would not be in use. I fear letting RV power feed to the FLEX SJB. See Diagram: www.jasonandginny.com/OurWebsite/Flexdownloads.html At the Dealer Flex 2011, Diagrams seem no or little change.

 

With my Flex, and perhaps with the MKT, I have been convinced of the need of a brake relay under the dash like I now have in my 04 Honda Odyssey. Roadmaster furnished me with one I personally installed. Studying the Flex Wiring Diagrams, it seems to me that like the Honda, a Brake Relay is needed that:

 

1. Relay coil is powered by fused circuit wired to "Ignition ON" so that the relay closes powered existing circuit to brake switch.

 

2. With ignition key in accessory position as is required for towing, then no power goes to the brake switch.

 

3. Without the Brake Relay, the brake switch with pushing the brake pedal, by foot or Braking Unit completes the circuit, and powers in my Flex and Honda the Brake lights.

 

4. The brake light in the Flex also is the turn signal element, that needs to flash properly on signal from RV without super flashing. Thus a load ballast is needed which I believe is in the LED tail light assembly.

 

Then if not understanding where to install diodes, certainly RV powered wires can be run to each tail light assemblies and install the diodes there for tail, stop and turn, so as not to back feed into Ford Flex wiring.

 

 

[jcthorne]

I wired our MKT myself using the Ford manuals. Connected each of 3 circuits to pin 2 of the trailer tow relay for left, right and running light. There is no seperate stop circuit. Diode is in the line from RV to pin 2. Applying power there seems to have no effect on the SJB and indeed ran our Explorer that way for better than 5 yrs.

 

Brake lights function from rv, MKT or both. When both are actuated there is no real difference. Turn signals work normally regardless of brake pedal position on either rv or MKT.

 

Its a simple 4 wire hookup in the engine bay. Ground and 2 wires to the SJB. No relay is needed. Did find out on last trip that Brake Buddy uses enough power that towing for 3 days without driving the MKT would drain the battery. Yes I started and ran it for 5 minutes each morning but that was not enough to maintain the battery. Valley Towing makes a charge circuit that I plan to add to keep the battery charged. It can either use the running lights circuit or an independant aux circuit from the RV.

[O HENRY]

I wired our MKT myself using the Ford manuals. Connected each of 3 circuits to pin 2 of the trailer tow relay for left, right and running light. There is no seperate stop circuit. Diode is in the line from RV to pin 2. Applying power there seems to have no effect on the SJB and indeed ran our Explorer that way for better than 5 yrs.

 

Brake lights function from rv, MKT or both. When both are actuated there is no real difference. Turn signals work normally regardless of brake pedal position on either rv or MKT.

 

Its a simple 4 wire hookup in the engine bay. Ground and 2 wires to the SJB. No relay is needed. Did find out on last trip that Brake Buddy uses enough power that towing for 3 days without driving the MKT would drain the battery. Yes I started and ran it for 5 minutes each morning but that was not enough to maintain the battery. Valley Towing makes a charge circuit that I plan to add to keep the battery charged. It can either use the running lights circuit or an independant aux circuit from the RV.

[O HENRY]

jcthorne Thanks. I now understand much better, after your last post and I have looked again under hood main at fuse relay panel, referred to Manual, and located Trailer Tow (TT) Relays. With a lighted magnification glass, and a removed Relay in hand, I have determined which is Pin #2. Ohm meter confirmed Relay function. Great to learn that power to SJB from RV does not cause a problem. The diode is placed to prevent auto power from back feeding to RV.

 

 

[jcthorne]

jcthorne Thanks. I now understand much better, after your last post and I have looked again under hood main at fuse relay panel, referred to Manual, and located Trailer Tow (TT) Relays. With a lighted magnification glass, and a removed Relay in hand, I have determined which is Pin #2. Ohm meter confirmed Relay function. Great to learn that power to SJB from RV does not cause a problem. The diode is placed to prevent auto power from back feeding to RV.

 

 

Yes, that's it exactly.

[sunpialia]

It is always good to use LED lights for cars instead of the normal lights that is being offered in the market.For which it has great attributes that is good for the environment and it saves a lot.