Exterior lighting dilemma | Ford Explorer Forums - Serious Explorations

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New Member
March 5, 2019
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City, State
Navarre, Fl
Year, Model & Trim Level
2002 Explorer XLT
Hello all,
I appreciate any help I can get on the following issue.

Background: I have a late build 2002 Explorer XLT 4.0. I recently changed all the exterior bulbs (minus the headlights so far) to LEDs. After replacing all the bulbs I made the mistake of changing the flasher, to an electronic one, without disconnecting the battery first. In doing so it triggered a flood of issues of which included various flashing instrument cluster lights and when I started the truck it didn't allow me to turn off the truck even when removing the key. I disconnected the battery, which stopped the engine, and let it set for a while then re-connected the battery. Everything returned to normal, and I have driven it since then, except for the front and rear turn signal/parking lamps and rear brake/turn/parking lamps. I have changed the flasher since and swapped both left and right front turn signal bulbs. I have looked over the schematics and diagrams quite a bit for the headlamp, turn signal, parking, and brake lights. I can't find solid evidence where all of these systems interact with each other except for the multifunction (turn signal) switch. The current issues are as such with the key in RUN, engine not running nothing is evident when the signal switch is in neutral:

With parking lights off and brake not pressed:
Right turn signal selected: operates normally.
Left turn signal selected: operates normally but causes the interior dash backlighting to cycle in sync with the blinking (indicating to me that the turn signal and the parking light are both flashing).
With parking lights off/brake pressed: both sets of front and rear parking and brake lights come on.​

With parking lights on and brake either pressed or not pressed:
Right turn signal selected: operates normally.

Left turn signal selected: left lights stay on (front and back).
With no key in the ignition (in the OFF position): pressing the brake causes the parking lights to come
on in the front and both tail and brake lights in the rear as well as the interior dash lighting to come on and the bell to notify me that the lights are on. This stops once the brake is released.
I have viewed the attached schematics. Thank you for your help.



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I apologize for my bluntness in advance...


I have tried it, what happens is them junk Chinese bulbs leak voltage back-feeding other light systems.

Your left bulb is back feeding into the parking lights which is lighting the dash lights.

The only exterior lights that can safely be upgraded to LED are the following:

1. Back Up Reverse Lights.
2. The 5 bulbs in the high mount stop light.
3. The two license plate bulbs.

Leave the rest alone unless you're going to try Philips which theoretically should work ok since they would be properly made to not leak voltage.

Front Turns: https://www.amazon.com/dp/B077FN5SZB
Rear Turns: https://www.amazon.com/dp/B077FTYFFX

Here are the bulbs I am using in my center high mount stop light: 6 x T10 Red 6 SMD5630 3W Super Bright 194 168 2825 W5W LED Car Lights Bulb 8809333840039 | eBay

Personally I like my Wagner Natural Amber Krypton bulbs in my front turns, very bright.

I have changed all exterior bulbs to LED, as well as installed an LED compatible flasher on my 2002 XLS and everything works fine.

I do agree that you should avoid the cheap Chinese LED’s, I had a set of them for tail lights and in one bulb the blinker would occasionally not work. I changed those to a new pair and have been trouble free since.

Even with that flaky bulb, I did not experience any of the issues you are describing.

Are you sure that you used the correct flasher? Did you remove anything to get to the flasher or did you just reach up into the dash to change it?

I appreciate both responses. I purchased the bulbs from superbrightleds.com. Didn’t think there would be an issue with them. I have purchased new 3157 incandescent bulbs to try out this afternoon. Will let you know what happens.

I purchased the bulbs from superbrightleds.com.

They're still Chinese. There is a bad diode in one of them.

Use Philips for just the 4 corners and you'll probably be fine.