When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I’m looking for some recommendations on LED bulb options for the rear fog lights on the ROW S4/GT/GTS models.
The bulb is a 1157 (BAZ15D) dual brightness style. Ideally, I would want something that has lower lumen side illumination for driving lights and high output projection out the top for fog.
I Tried a couple options form superbight but the low lumen mode is too bright and the high lumen mode is not bright enough to notice a difference especially when compared with a incandescent
The incandescent bulb specification is
8.3 watts (125 lumen) for driving lights
27 watts (400 lumen) for fog lights
options are appreciated.
Last edited by Michael Benno; 01-17-2022 at 11:34 PM.
Mike, that rear fog bulb is spec'd the same as the combo run/brake bulbs in 1157 flavor on the Euro cars. The fog function is the same brightness as the brake lights.
When looking at rear fog and LED options a few years ago, I considered adding a few diodes with the LEDs so the fogs would light up with the regular brake lights, but not the inverse. Works with LEDs only unless you go after bigger 5A diodes, btw. Trying to do this without modifying the factory socket, just adding/extending those with trailer-light adapters and modified Ford sockets per the many suggestions here in the forum.
Michael,
no markings on the bulbs. From my records they are a Baz15d 1157 bulb.
Myles
Thanks for looking Myles. I have a set of those in amber that I got from woodypeck when I was trying to convert my front blinkers. The bulbs didnt work with my blinker relay but I'll give them a try in the rear for brightness and color. Thanks for the insight.
Originally Posted by dr bob
When looking at rear fog and LED options a few years ago, I considered adding a few diodes with the LEDs so the fogs would light up with the regular brake lights, but not the inverse. Works with LEDs only unless you go after bigger 5A diodes, btw. Trying to do this without modifying the factory socket, just adding/extending those with trailer-light adapters and modified Ford sockets per the many suggestions here in the forum.
I'm not sure I understand what you are accomplishing with the doide? Could you explain a little more about what the diode does? That a dual brightness LED doesn't?
For reference, my USA model car has EURO rear tail lights, so the outward most bulb is a dual function, fog/driving light. I added a pod rear fog switch and connected the necessary wires at the CE panel to run the fog independently (USA cars have the rear fog lines in the harness merged into the the parking lights).
Was thinking of adding a diode on each side between the brake light circuit and the fog light circuit at the lamp housing. When brake lights are active, the diodes would forward-conduct current to light the fog light cell so they would light up with brakes whether the fog light circuit is active or not. With fog light circuit already active, the fog light is already lit up so there's no current flowing through the diode even when brake light is active. The diode doesn't conduct power back to brake lights from fog lights, so having the fog lights active doesn't illuminate the brake lights.
Was thinking of adding a diode on each side between the brake light circuit and the fog light circuit at the lamp housing. When brake lights are active, the diodes would forward-conduct current to light the fog light cell so they would light up with brakes whether the fog light circuit is active or not. With fog light circuit already active, the fog light is already lit up so there's no current flowing through the diode even when brake light is active. The diode doesn't conduct power back to brake lights from fog lights, so having the fog lights active doesn't illuminate the brake lights.
The diode prevents the fog light function from back feeding the brake light circuit and turning on the brake lights.
01-20-2020, 01:39 AM
ROW rear fog LED options for S4/GT/GTS
