Problem with LEDs in Illuminated Reflector

[RAC68]

Problem with LEDs in Illuminated Reflector

Today I installed 1156-based LEDs within my rear reflectors to serve as added directional and brake lights. To simplify the task, a power and ground wire was spliced into the corresponding taillight. Initially implemented using low watt high intensity incandescent bulbs, however, due to a stuck-on brake switch, the high intensity bulbs created sufficient heat to begin lens melting.

As an alternative, I decided to replace the incandescent bulbs and chose very low heat 12-volt 1156 LEDs advertised as 1156 BA15s directional and brake light replacements. After installing the LEDs, no light was emitted when the directionals were activated. The LEDs did light when tested using power sourced directly from the battery.

As this is my first use of LEDs, I would appreciate any thoughts and/or suggestions.

All the best,
RAC68 (64BJ8P1)

 

[GregW]

If your car is still positive ground, you'll need to get special LEDs marked + ground or they won't work.

 

[RAC68]

Thanks Greg, I was unaware that the LEDs are polarity sensitive. My Healey has been converted to negative ground and uses an alternator (if that means anything). After checking the advertisement (no markings on the LEDs), they seem to be for negative ground use.

Thanks for your reply,
Ray (64BJ8P1)

 

[terp83]

Ray,

Refer to a thread under the Triumph forum entitled: "LED Turn Signal Indicator Lamp." (Last post to the thread was December, 2010). An owner had entirely swapped his incandescent auxiliary light system over to LED, but had not switched the flasher. He was advised to swap to a flasher specifically for LED lights. As was explained, the "load" from LED's was less, and was never enough to trigger the stock flasher. It was not necessary to replace the flasher in a circumstance where LED's were added to the incandescent lighting system (in the place of the upper rear reflectors) as the remaining incandescent lights would still provide enough load for the stock flasher to work.

I hope that this helps,

Jerry

 

[Cottontop]

As an alternative, most places that sell LED "bulbs" also sell a "Load Resistor" that goes in parallel between the turn signal bulb power line and ground.

Because some flashers are 2 contact, some are 3 contact, and there are some very weird wiring configurations, adding this resistor allows the use of the original mechanical flasher.

Check with the manufacturer of the LED bulbs and see if they sell the load resistors. If not, they are available from many other sources.

Tim

 

[RAC68]

Hi All,

Thanks for your responses. I hate to say it but this was a case of my stupidity causing the problem.

Your comments stimulated me to review my auxiliary light wiring. Although I initially thought Greg’s response was not applicable as both car and lights are negative ground, his indication that a reversed polarity would keep the lights from illuminating started me to review the polarity of the white and red wiring used to install the auxiliary lights.

In the documentation I keep for all changes to my Healey, I found a note reminding me to replace the red wire with black once I repurchase appropriate gauge black wire. Since I hadn’t and commonly use red as positive, I had the polarity reversed and the LEDs would not light. Reversing the leads and the LEDs work as hoped.

Jerry/Tim, since I am still using incandescent 1157 bulbs in my taillights, no resistor or electronic flasher is necessary. Based upon this success however, I will probably replace the parking and tail lights with LEDs and require an electronic flasher.

My objective is to reduce amperage through the 45-year old Flasher relay box. An alternative is to place 2 relays near the taillight assemblies to reduce the major load on the box and its contacts. The relays would reduce the load on the box and provide a direct 12-volts for tail, brake, and signal lights. Any thoughts?

Again, thanks for your support and I have to admit my stupidity was the problem in my LED installation.

All the best,
Ray (64BJ8P1)