View Full Version : Switching to LED bulbs. Are Resistors necessary?

David Kasprzyk
06-16-2018, 09:13 AM
Hey All! I just got my 500E (Orange 2014 w/black interior and sunroof)
I want to replace the anemic headlights, drl's. and turn signals with led bulbs. Has anyone tried this? I was wondering if Resistor packs are necessary?

All help is much appreciated!!!

06-16-2018, 05:00 PM
Here's a thread on the topic: http://www.fiat500usaforum.com/showthread.php?26903-Will-LED-s-work-on-our-head-lights-tail-lights
There are many more relevant threads in the gas Fiat 500 sections of the forum. The lighting electronics are the same as the 500e.

David Kasprzyk
06-16-2018, 08:33 PM
Thanks for the assist!!!!


Dirty Blond
06-16-2018, 10:56 PM
Resistance is futile....

David Kasprzyk
06-25-2018, 08:59 PM
I'm just finishing up on installing all led lights on my 500E. Headlights were basically plug and play. I did have to cut cooling holes in the round plastic dust covers. Front turn signals were weird. I had to order 2 different brands of supposedly "canbus ready" led amber turn signal bulbs. First set wouldn't work and second set was indeed plug and play. Rear signals had to have load resistors on each bulb. Reverse lights only needed one load resistor and both lamps operate. Stop/Tail light lamps were very screwy!!!! The Tail light section of the bulb is plug and play with no load resistor needed but the brake light section did require a load resistor on each bulb in order to work. Go figure! Also the Front parking light/ DRL lights have not been changed yet. I'm having trouble locating a true led replacement for the W21/5W Dual filament bulb. Do NOT use the sub most suppliers recommend. The 7443. It only has one "filament" so to speak and does not work correctly. Also there is a difference in the base of the rear turn signal bulb if you get an 1156 led and a true PY21W led. The locking tabs on the PY21W are NOT 180 degrees apart from each other like the 1156 are. To see what I mean look at your PY21W bulb. You'll see what I'm talking about.


06-25-2018, 09:16 PM
Do not recommend this. Switched over to LEDs using high quality and had nothing but problems. Switched back to incandescents and everything is fine again. Had issues with ghosting and BCM issues.

06-25-2018, 10:53 PM
I installed one LED headlight on the driver side and left the incandescent bulb on the passenger side. I had to use a hole-saw to cut a circle for the cooling fan/heatsink...the whole install took 8 minutes. I'm hesitant to install the other side because the LED headlight is not quite ideal. There's a few blindspots in light dispersion (just the nature of diodes on a stalk), so I rotated the bulb so that the area of low light dispersion are covered by the fog light beam area. I may scrap the whole LED thing and try HIDs instead.

As for the rear, we recent had the brake light bulb burn out. I replaced it with a standard 21/5W bulb, but will consider the Euro LED lamp the next time a bulb goes bad.

12-09-2018, 04:15 AM
There are now blinker bulbs with built in resistors. I was able to replace all 4, super bright and work perfectly.

12-09-2018, 02:22 PM
There are now blinker bulbs with built in resistors. I was able to replace all 4, super bright and work perfectly.


12-13-2018, 01:44 PM
I've tried 5 different brands of resistor-included amber LEDs. My favorite by far have been Lasfit

They are very bright (a little too much IMHO) but that's been a common thread among all of the ones i've tested.

I like these because of the color shade of the amber they produce but the main reason I like them is their overheat behavior. Because they have the resistor onboard they get very hot. After running for a few minutes they will automatically shorten the flash time. They don't hyper-flash, just a shorter blink. The good news is the car will let you know when this happens. After they have been off for a short while and have cooled off they return to normal and the vehicles bulb out indicator will go away the next time you use them. This is much better behavior than some I tested which will simply stop blinking(!!!)

Front (https://www.amazon.com/gp/product/B07CMSD8CS)
Rear (https://www.amazon.com/gp/product/B07CMT1Q6Y) (These weren't a perfect fit in the socket but I managed to squeeze them in)

I've tested multiple dozens of LED bulbs between my two cars and have everything converted except for the rear brake lights in the Fiat. It's so freaking picky!