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LED bulb conversion - Alternative load resistor install

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My SHO is currently a leased vehicle, yet I definitely have the bug to improve the looks and performance. So far I have not made any permanent changes to the car and installing load resistors for my front turn signals was not something I was looking forward to. I tried several different bulb types hoping I could avoid it.

The proper way to prevent the hyperflashing is to remove the SJB (Smart Junction box) and modify the resistor value going to the FET that controls each signal bulb. Not having enough data to achieve that, YET :RpS_sneaky:, I sought alternatives.


I found this site that sells the stock socket and pigtail harness (with appropriate female plug) found on the vehicle: Click for the Pigtail - Click for the socket. You will need 2 of each so you can do the left and right front turn signals. These same sockets are listed to fit 2010 - 2012 Taurus as well as a host of other Fords.

With these 2 items I can now make a harness, that goes in between the stock socket and car wiring, which includes the load resistor. This makes the modification totally reversible and prevents me from using the dreaded scotch locks.


In my haste I forgot to take photos of some of the steps. I will be glad to answer any questions if what I post is not clear.


First you can see the stock socket and how it removes from the car wiring harness:




(Closeup of stock socket for reference)

1st you want to remove the rubber o-ring. Now, using a hacksaw, cut around the circumference of the "black" plastic. *NOTE*: On the replacement, this plastic was gray. Be careful not to go too deep because you will start digging into the metal contacts. Once you have achieved what you feel is enough cutting, a pair of pliers allowed me to pull it straight off, remaining mostly whole. You can now use the hacksaw to cleanly remove those 2 locking tabs that grab the bulb.




This is where more pictures would have been nice, oops.

I did not remove any more plastic than my above description. The four metal contacts are now well exposed and you can easily solder the pigtail to them.


1. There are 3 pins coming into the socket and 4 contacts where a bulb normally would have been seated. 2 of the bulb contacts are ground and are both tied to 1 of the "outside" 3 pins. It should be the pin nearest the lock tab where the socket plugs into the wiring harness. You should use an ohmmeter to verify and mark which 2 contacts both have continuity with that 1 pin.

2. The middle pin is for the parking/running lights, you should use the ohmmeter to find which of the 2 remaining contacts corresponds to this and mark it.

3. The other "outside" pin is for the turn signals and will have continuity with the 1 remaining contact.




Now we have our socket "mapped" and can proceed with soldering.

This is where you could go further with plastic removal for a possibly "cleaner" end result with the soldering. I chose to solder directly to the existing contacts.

A. On the "pigtail" you will want the wire with the yellow stripe along with 1 end from your load resistor. Solder those to the 2 ground contacts on your socket. Using both contacts is totally subjective, you can use just one if you want.

B. Take the middle wire on the pigtail and solder it to the contact that you identified in #2 above.

C. Take the remaining wire from the pigtail along with other end of your load resistor and solder to the remaining contact. (Should be the one you identified in #3 above).


Your harness is now complete. You should verify continuity from each pin on the socket to each corresponding female receptacle on the plug end of the pigtail. You can also check the resistance between the 2 outside receptacles, it should match the resistor value that you purchased (6ohms in my case).





I covered all my soldering and the contacts with silicone and let it set to avoid moisture/corrosion. I then wrapped everything in electrical tape.

My second turned out better/neater (the one with no red tape) than the first. Overall, I probably should/could have planned a bit more before cutting and I would have ended up with a much more aesthetically pleasing result. I am not really bothered though because they are tucked well out of sight under the hood.




Here is the harness connected to the car. The socket end plugs right into the car and then your factory bulb socket plugs into your harness.



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Another option would be to pick up the appropriate pigtail, or load resistor jumper, from this place. They have quite a variety of setups, most of which show up about 1/4 of the way down the page.


On my Aviator I removed the cap from the backside of the plug, slid out the weather seal, inserted the load resistor wires through the cap and seal, stripped the wire, folded it over, and wedged it between the terminal and the connector housing, then reassembled. The weather seal so far is doing a good job of making a reliable connection that will be easily reversible if I decide to go back to standard bulbs.



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Here's what I did on the Aviator. I'm not sure how applicable this would be to the SHO though.






I used self-fusing silicone tape instead of electrical tape to aid in being able to reverse the install. I holds well, is weather-proof, and will not leave any residue when removed.





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One last question, could you reference the LED bulbs you are using in the turn signals, as well as to where you picked up the resistors? Lastly, after re-reading your post, it really is a great idea to purchase the additional parts and hence you can plug and play with the new LED ones you make and still have the stock harness, should you need it!:thumb:

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Not sure which person you are directing the question to.


On the SHO, there are no green/red wires. Both leads of the resistor are black and there is no wrong way to hook it up. It doesn't have a positive or negative. You need one of its leads to the turn signal "signal" wire which is the outside black wire in the harness you make. The other outside black wire has a yellow stripe, which is the ground.

You just need the load resistor to go between those 2 wires, the load resistor doesn't care which is ground and which is the signal wire.


The bulbs are the 120 LED switchbacks from autolumination.com and I got the 6 ohm 100 watt version of the load resistors from them as well.

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Actually it was kinda directed towards both of you, so thanks for the input, this is something I've wanted to do, but I'm not really great with electrical stuff, so I need all the input I can get to make sure I do it right! Although, I'm not sure what you mean by "Switchback". A picture of the bulbs you used would be helpful. Thanks.

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I guess I should have bolded that the pics I uploaded are NOT of an SHO, but rather my Aviator, as another option for wiring in the resistors in a way that is easily removable. 83racecrew already answered that resistors are not polarized, therefore there's no direction they need to be installed.


Switchback lights are ones that light up white with just the parking lights, but "switch" from white LEDs to amber LEDs when the turn signals are triggered. The Autolumination site referenced a couple of times in this thread have a link to another website that will list what bulbs are stock in your vehicle, then you can check the site for the related LED version of that bulb type.



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http://autolumination.com/3157_3156.htm Scroll down the page (no way to link the bulb directly because their website is so stupid), you will see "New" "Introducing the Switchback" "New" and then "Two Colors - One Bulb" in big red text. The next several choices are the switchback bulbs.

I have chosen the 120 LED model on the far left of the row that includes the 120, 92, 60, and 39 LED styles.


For Load equalizers, I have chosen the 6 ohm, 100 watt model (big gold heatsink) from this page: http://autolumination.com/equalizers.htm Again, you will have to scroll most of the way down.. probably about 3/4 on your scrollbar. On far right of the row showing all the resistors, I chose the 100W and then 6ohm. 100W doesn't get as hot and using 6ohm gets you about 25-30 watts of load rather than 50. Seems to be enough to make a nice steady turn signal flash, no hiccups there yet.


With all that said, I may not be doing business with autolumination anymore. I have been going back and forth with them a good chunk of last night and today because the bulbs are not working right. They seem to think my wiring is wrong, but I very carefully measured all the scenarios and my wiring matches the stock wiring perfectly, except for the added load of the resistor (which they insist I have to have of course, especially with the switchbacks).

I "blew up" 1 pair of bulbs because I didn't have the resistors (or so they say, no refund). This second pair is acting crazy, so I kind of think the 1st pair had a fault too.


I had also purchased a pair of the "27 Watt Osram Eagle EYE SMT Tower" in Amber (go back to my first link and it is the first bulb listed on the page under the header info). They are nice and bright and work 100% perfectly with my current setup.

I really like the effect the switchback offers, mostly because when you unlock the vehicle and the parking lights stay on, you get white light out the front rather than amber. It makes approaching the car at night just that much more clear.


Hope that helps :)

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