Left headlight led issue

jeep4465 · Jan 28, 2018

Hello everyone, I'm having an issue with my 2005 ST 1300, I went to change out all the headlights and marker lights to LEDs this last weekend, my left headlight has blown twice in the past one year. I replace both headlights with LED in the right one works awesome, the left-hand will not light up. Flipping to high beam and low beam makes no difference, but the high beam indicator is bright on high beam, and is dim on low beam. Does anybody know about this issue and how I can fix it. Thank you

flip-flop · Jan 28, 2018

did you try swapping left for right to see if the issue migrates? What brand LED?

jeep4465 · Jan 29, 2018

Yes, I've tried swapping the right one and the same issue. I even have a brand new OEM headlight, and that doesn't light up on the left side, so I'm assuming that the light isn't bad. I can see no damage to the wires. Still don't understand why high beam indicator glows dimly on low beam.
Here is a pic of the led headlights I put in.

Nashcat · Jan 29, 2018

Anytime I've seen an issue with dash indicators acting weird, it's always been a ground wire problem in one on the connectors. I've fixed 3 with the problem, including my own.

One is the 26? Pin connector, behind the upper left cowl. The other is the yellow multi connector under the front cowl, above the right headlight. Here's a pic of the yellow connector I repaired, just a couple of weeks ago, on Seawalker's bike. You can see the connector that was hot. There are several threads describing the fix.

Ride Safe
John

dduelin · Jan 29, 2018

Nashcat said:
Anytime I've seen an issue with dash indicators acting weird, it's always been a ground wire problem in one on the connectors. I've fixed 3 with the problem, including my own.

One is the 26? Pin connector, behind the upper left cowl. The other is the yellow multi connector under the front cowl, above the right headlight. Here's a pic of the yellow connector I repaired, just a couple of weeks ago, on Seawalker's bike. You can see the connector that was hot. There are several threads describing the fix.

Ride Safe
John

+ 1 on all of that.

You might also fashion a jumper wire and insert one bare end into the side of the left headlight connector with the green wire and touch the other end to the frame nearby and see if the LH bulb lights and the high beam indicator returns to normal. The LH bulb connector often develops high resistance thus overheating and damaging the yellow buss and 24 pin connector mentioned by John.

playfair · Jan 29, 2018

Checking ground is a good idea, but also I believe the left headlight is powered through relays whereas the right one is directly from the switch.
Does high beam work? The run separate relays under the left side cover... Possible one is loose or failing?

Turbine2 · Jan 29, 2018

+1 on the poor earth here. I used to have an FJ1200 that did odd things sometimes when the inticators were used, turned out to be the earth from the front pilot light.

jeep4465 · Jan 29, 2018

No high or low on the left side. I think I'll look into the grounding issue when I get off work.

SupraSabre · Jan 29, 2018

You could always hook up a SDC Headlight modulator and run both headlights off the right side!

spiderman302 · Jan 29, 2018

here is the basic schematic of the light system on the ST1300.

If the left lamp ground is open then that would explain why your hi beam indicator would be dim on low beam and no left lamp.

check all the green wires that go to ground.

Anna'sDad · Jan 31, 2018

jeep4465 said:
Still don't understand why high beam indicator glows dimly on low beam.

A poor connection to chassis ground at the left-hand headlamp will cause the high-beam indicator to light up.

Take a look at this schematic I made when I was experiencing a similar problem with my '06 ST1300/A. In my case the ground conductor had overheated, probably due to poor electrical contacts at the headlamp connector.

dduelin · Jan 31, 2018

Anna'sDad said:
A poor connection to chassis ground at the left-hand headlamp will cause the high-beam indicator to light up.

Take a look at this schematic I made when I was experiencing a similar problem with my '06 ST1300/A. In my case the ground conductor had overheated, probably due to poor electrical contacts at the headlamp connector.

I also had the identical problem as the OP some years ago and fixed it with a dedicated ground from the LH headlight connector to the threaded bolt hole found on the left side of the frame behind the head stock.

Freddy3001 · May 20, 2018

GoodDay All. I have the left H/lamp out issue. ( Right OK ) I found the 10a fuse blown. RE-fused. Both H/lamps work. I suspect the left will die in the first few Hours of riding. I plan to take Dave's tac and hard wire a ground. Thank's to Dave and Anna's Dad.
F

Left headlight led issue

jeep4465

flip-flop

I do not consent to a search...

jeep4465

Nashcat

dduelin

Tune my heart to sing Thy grace

playfair

Turbine2

jeep4465

SupraSabre

48 Years of SoCal Lane Splitting/Commuting-Retired

spiderman302

Anna'sDad

dduelin

Tune my heart to sing Thy grace

Freddy3001