Adding LED Tail Lights

[Mountaineer302]

We are interested in upgrading to LED tail light bulbs in our 2001 Mercury Mountaineer. I know that there was as issue with doing this on my 1994 F150 that caused cruise control not to work and the torque convertor not to lock up. Is this also a known issue with Mountaineers and Explorers?

 

[Blown]

I run them but had to change the flasher to a low load flasher/ LED flasher

 

[Mountaineer302]

So, you did not have to add load resistors to the tail light harness? I'm good with upgrading the flasher. Ours has amber rear turn signals. I'm more concerned with the brake lights being LED and not having sufficient resistance to keep the transmission and cruise control happy.

 

[CDW6212R]

The transmission and CC are unaffected, only the issue of the lower current has to be dealt with.

Some rare occasions have reported an effect on trans shifting, but it seemed fixable or related to more than just the LED's.

 

[CDW6212R]

I run them but had to change the flasher to a low load flasher/ LED flasher

Very good, interesting what flasher specifically did you use?

I had one tail light bulb going out semi-regularly last Summer. I had bought LED bulbs before deciding to use them to fix my bulb issue. I had already replaced the flasher and the bulb socket, and was about to cut the main pigtail section off. Then I started to try the LED bulbs. One worked fine alone, two would create the lights off strobe affect. After some days the single one was strobing, so then I installed the resistors(plug and play adapter harnesses). After a few months one of the wires and a terminal in the adapter burned apart. That was the previous good side, so I left out the adapter and put the old incandescent bulb back in. I need to figure out how to lower the current on the LED side, the resistors are using too much current and the adapters are I think low quality.

 

[Mountaineer302]

That's good to know that the transmission etc are unaffected. On many Ford trucks having little or no resistance causes problems like it did on my F150.

I looked at many bulbs before deciding to try the Putco Plasma LED. They aren't cheap, but are the brightest I've seen. Amazon has the best prices.

Your frequent bulb failure sounds like a weird problem. Is there a bad ground?

I used the Sylvania resistors most stores carry on the F150.

 

[CDW6212R]

That's good to know that the transmission etc are unaffected. On many Ford trucks having little or no resistance causes problems like it did on my F150.

I looked at many bulbs before deciding to try the Putco Plasma LED. They aren't cheap, but are the brightest I've seen. Amazon has the best prices.

Your frequent bulb failure sounds like a weird problem. Is there a bad ground?

I used the Sylvania resistors most stores carry on the F150.

There are tons of LED choices, brightness definitely, quality too of course. I chose a couple aiming for near stock levels, for my work truck.

My lights weren't ever a problem, until I used the truck for about 9+ months straight, with the flashers running all the time. Delivering mail discovers many weak links of various systems. I replaced the bulbs for my headlight once, then the right tail light twice in about three months. When I had the LED bulbs in hand, then I replaced the bulb socket, and was about to replace the pigtail end and the connector. I first tested for grounds, and power to the terminals. There are two circuits in that receptacle, for brakes and the flashers. I didn't find any problem using the multi-meter, so I puled the left side out, and found the same results.

That's when I began trying the LED bulbs. For some reason, the incandescent bulbs(both sides) worked in the left side, but not in the right. That's not good of course, the testing wasn't sensing whatever the issue is. But the LED bulb would work in either side. So I put the first one in the right side, and weeks later installed the resistor adapter harnesses, and the other LED bulb. It was about five weeks ago that the light went out again, and I found the resistor harness burned up. I removed it and put the regular bulb back in. I need to decide now on what next to do with it. I've avoided running the flashers and head lights full time, to reduce the current running in the circuits.

 

[J_C]

^ Depending on what construction the resistors are, if encased in an extruded aluminum body you can mount them on heatsinks with thermal grease between the two, or put a few diodes in series in the lead to the resistor to drop some voltage, or of course get lower resistor values if it turns out that the circuit doesn't need that much resistance... depend on how the bulbs were designed, if these things reduce overall circuit current or just increase it to make up for the lower voltage.

Overall, upgrades is not what I would call LED bulbs in most stock bulb locations, not the off the shelf drop-ins anyway.

 

[CDW6212R]

...

Overall, upgrades is not what I would call LED bulbs in most stock bulb locations, not the off the shelf drop-ins anyway.

Agreed, most vehicles are requiring the stock current in each circuit, and the resistors end up using the current the LED's dpn't need. I'm going to hope a different flasher does exist that is made for the lower current, and it will suffice.

 

[Blown]

I am running Ranger front lights. For turn signals and brakes in the rear, I run LEDs as they are a little brighter. They are not blinding and should last longer than incandescent. I go them originally to run in tinted housings. I run incandescent in the front turn signals as I couldn't find a brighter than incandescent LED at the time I looked. I run a bit brighter than stock LEDs in the running light positions but not for the license plate. I do run LED back-up lights.

All I had to do was get the correct flasher, simple.

I see people running stupid bright blinding lights which are a hazard! I think law enforcement needs to catch-up with LED's and stupid bright headlights.

 

[CDW6212R]

I agree, front facing lights should be no brighter than one pair of normal headlight bright lights. Stock vehicles have been coming with extra pairs of headlight bright lights for years. People use them because they like the look, and don't care about the visibility of oncoming drivers.

 

[J_C]

Agreed, most vehicles are requiring the stock current in each circuit, and the resistors end up using the current the LED's dpn't need. I'm going to hope a different flasher does exist that is made for the lower current, and it will suffice.

Yes any of the same form factor (pinout) called an electronic relay or suitable for LEDs should work. They must be a timer design that ignores current, then you can get rid of the ballast resistors.

They're on Amazon for about $8 and up. Problem is figuring out which are good quality and which are Chinese junk. Reviewers may just give some a high rating before enough time has passed to know the lifespan.

Autozone has one that looks compatible for $16, Novita EP27:
https://www.autozone.com/electrical...ovita-turn-signal-flasher/849387_642227_11714

 

[CDW6212R]

Thanks J C, I did replace the flasher early on when the issue started last Summer. I think I used an electronic flasher, as I usually do. Whether it's the type made for low LED current only, I don't know. I have a spare used flasher inside the container of the new one, in my truck. I'll take a look at it later, I wouldn't mind changing the flasher again if I could throw the LED's in and stop the current/heat problem.