Light socket type and Info on LEDs

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Skitter302

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Hey guys,

I'm trying to put LED's in the Bronco, have an electronic flasher that prevents hyper flashing. So no resisters needed to fix that issue. I am having issues with the running lights and the Brake lights.

With the new LED bulbs, my running lights turn on my LEDs at max brightness. This effectively casuses an issue where my brake circuit won't make the lights brighter. My question is Does the 91 Bco have the 3157 Ck light socket design and not the regular 3157?

I'm gunna pull the wiring apart in a few days just wondering if anybody here has an answer to this.

btw! I did put LED lights in the Front turn signals and they work issue free. This is just an issue with the rear lights. Everything works great with the factory bulbs just not the new LEDs.

MxUbPIG.png
 
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Skitter302

Skitter302

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Nope, I got a set of clear lenses from http://aftparts.com (I would not recommend buying lenses from this site. The fitment is loose compared to OEM lights.)

And I got the LED bulbs from Amazon. I'm having a compatibility issue with the LED lights and my E4OD. I'm working with my Dad who got is electronics degree long before I was born To come up with a diode and resister combo that will get the LEDs to work with out back feeding 12v to the rest of the lighting system and keeping the E4OD from locking the torque converter and randomly engaging the cost clutch solenoid.

When somebody posted that the brake lights in the Bronco effect how well the e4od performs I thought they were full of it. I get to eat my opinion now and face the fact the you can back feed the 12v on the lighting circuit in to the turn signal/multi-function switch and that will cause the transmission to think your on the brakes. A lil' bit more engineering and this wouldn't be an issue but Ford didn't plan for LEDs.

As always I'll post up my findings.

 

miesk5

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Yo M,

Ok, will await results, ty.

The brake on/off switch tells the powertrain control module when the brakes are applied. The switch is closed when the brakes are applied and open when they are released. The PCM uses this signal to disengage E4OD torque converter clutch when brake is applied.

  GL!

 
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Skitter302

Skitter302

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Broncos with the 3157 Rear lights do not have the CK type wiring.

 
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Skitter302

Skitter302

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So I got the new components installed and tested. As a reminder we were trying to fix this problem....

With the new LED bulbs, my running lights turn on my LEDs at max brightness. This effectively causes an issue where my brake circuit won't make the lights brighter.
I believe This was a result of voltage back feeding into the brake/turn signal circuit wiring. The LEDs on the market have a large tendency to bleed voltage from the running light circuit into the Brake light circuit. This also means that for those of us that have E4OD transmissions, the voltage that is back feeding the running light circuit and causing brake lighting issues will also cause transmission shifting issues because the Voltage will back flow to the BOO wire at the EEC. That connection would end up being energized with a false signal that brakes are activated and disengage the torque converter lockup and may also engage the Coast Clutch Solenoid. This effectively would fight the progress of the engine trying to move the Bronco forward which could result in a overly warm transmission.

The solution to this issue is to isolate the REAR LED 3157 lights from all the other signal wires. Had Ford done this in the factory they could of added relays or diodes in harness. Since this is a after market install all the work now nneds to be done in the rear of the vehicle.
NOTE: If your wondering why only the rear needs to be isolated Its because the turing signal switch isolates the front lights already.
Supplies:



I choose to use Schotty diodes due to their low voltage drop of only .367v compared to that of a Silicon Diode of ~.7v. Losing almost a whole volt of lighting power isn't good. .3v isn't ideal either but its be best option I could find. During my research I also found out that Load resisters are needed so the cruise control would function properly. The explanation on this wasn't very clear of how or where the cruise control ties into the circuit but not having them results in the Cruise control not working but as I had one Bronco owner explain it, "Voltage is bled off through the filiment of the bulbs to know if the brakes are pressed or not." Thus by installing LED bulbs voltage can't bleed off making the circuit think the brakes are being pressed.
NOTE: The resistors are needed because they provide a path to ground after the brake switch has been released. This helps the transmission and Cruise Control function properly. In some cases if the BOO wire on the EEC 60pin connector has any voltage the EEC can change the timing of the engine cutting power, Hold gears longer then desired(E4OD), and not allow the Torque Converter to lock up(E4OD).

Hear is the wiring diagram that I made to explain what needs to be made to isolate a 3157 LED bulb.

xXqyzxM.jpg

NOTE: (In the photo I used 1 6ohm resistor, I had to update my wiring because I found that a 12ohm worked better.)

The Diodes stop current from flowing backwards in the circuit. Heat shrink tubing is used like crazy to keep dirt and water out of the connections.

*** You must solder the diodes to the wire that you are putting the blue connectors on.

And here is the result of what parts were made:

c2rhCMs.jpg

The result looks messy but is cleaned up with zip ties

PSepMFq.jpg

JtbZBZq.jpg

At the time of this post I havn't tested the the set-up on a long trip around town but my lights do work correctly now.

I've been runnning this set up in multiple vehicles for 2 years now with no issues.
 
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miesk5

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Yo Skitter,

Fantastic narrative, thank you!

When you test it on road, after awhile we can make this a sticky or c&p into a single page project description,

Al

 

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