Russbus

Member

• Oct 27, 2019

• #1

Hi All,
I replaced my dash lights on my landy with a set of led bulbs but now the charge light stays on with engine running so I put the original bulb back in and that glows very dim its hardly noticeable.
Am I right thinking I probably have a fault and the led bulb draws so little power that it stays bright so I could have had the fault for a while and not noticed the light before due to it being on so dim.
I did have a flat battery 2 weeks ago but recharged it over night and it's been fine since, I've had the battery checked and it's OK.
Thinking I may need to get alternator checked anyone else had similar issue, I needed a new bulb in right hand dash light so thought I would replace the lot, solve 1 problem and create another lol

 

R

rob1miles

Well-Known Member

• Oct 27, 2019

• #2

1 LED bulbs don't work as a charge light, a number of us me inlcuded have found out the hard way. They don't pass enough current to excite the alternator.
2 Get the alterntor checked as it may have a diode fault.

 

Europa486

Well-Known Member

• Oct 27, 2019

• #3

Yes you have a slight feedback from your diode on the alternator, with a tungsten bulb probably barely shows
But with a LED it will be more than enough to shine brightly,

 

Russbus

Member

• Oct 27, 2019

• #4

Thanks for the info will nip to local auto electrician tomorrow to test it

 

Russbus

Member

• Oct 27, 2019

• #5

I'm not fully clued up on the workings of the alternator on the electric side( I have replaced bearings last year) just know basics but from the reply it seems the led bulb has brought an issue to my attention sooner than the standard bulb would have done so is that a plus for led bulb? What is the fault that did not show up for you and others, cheers Russ

 

mystery

Well-Known Member

• Oct 27, 2019

• #6

if you want to use a Led in the ignition warning light you need to fit a 100 ohm 3 watt 5% resistor across the bulb holder as fitted to the early defenders they also fitted a diode later on

 

Russbus

Member

• Oct 27, 2019

• #7

mystery said:

if you want to use a Led in the ignition warning light you need to fit a 100 ohm 3 watt 5% resistor across the bulb holder as fitted to the early defenders they also fitted a diode later onView attachment 192768

Click to expand...

When you say across the bulb holder does that mean one wire to + wire to light and one to -

 

R

rob1miles

Well-Known Member

• Oct 27, 2019

• #8

I looked at this having fitted all LED intrument bulbs including the charge light and indicator light in the Tex-Magna and I came to the view it was largely a failed experiment. The charging light had to be replaced with a bulb to excite the alternator, the indicator one blinded me and the instrument ones were too directional and only lit half the faces and to cap it all the life of the LEDs seems to be about the same as the bulbs.

 

mystery

Well-Known Member

• Oct 27, 2019

• #9

the resistor is parallel to the lamp holder the idea was if the bulb failed the alternator would still charge so across the white ignition feed and brown /yellow .on the later defender a diode was used in series with th

e brown/yellow