Novsight N39 LED headlights issue

[Menganicoy]

I recently installed new LED headlights on my trusty old 2003 Toyota Revo. It's working alright except that sometimes it gets stuck on high beam and would only go back to low after a good number of tries. Anyone ever had this issue? Any ideas on what's wrong? Thanks in advance.

[oj88]

I would think that your hi-beam relay is sticking.

[Menganicoy]

I would think that your hi-beam relay is sticking.

Thanks for the response. I've had a car electrician go over the connections and he says everything's fine.

[dr. d]

I recently installed new LED headlights on my trusty old 2003 Toyota Revo. It's working alright except that sometimes it gets stuck on high beam and would only go back to low after a good number of tries. Anyone ever had this issue? Any ideas on what's wrong? Thanks in advance.

them bulbs have no moving parts.
so i think, like OJ, it's your switch or solenoid, that's sticking... intermittent malfunction...? those are not very easy to diagnose, because they're... intermittent.
unless! it's the bulb itself, that's defective... although... it might be unlikely, as both LED bulbs are malfunctioning at the same time...

so might i inquire, what did your guy do to relieve the issue?

[Menganicoy]

them bulbs have no moving parts.
so i think, like OJ, it's your switch or solenoid, that's sticking... intermittent malfunction...? those are not very easy to diagnose, because they're... intermittent.
unless! it's the bulb itself, that's defective... although... it might be unlikely, as both LED bulbs are malfunctioning at the same time...

so might i inquire, what did your guy do to relieve the issue?

I had him replace the old relays and check the wirings prior to installation of the LEDs because they're really, really old. The thing is, it doesn't happen every time I switch from high to low or vice versa. It's quite random. Same as you, the electrician says it's probably the LEDs themselves that are defective when I called to tell him about the issue afterward. But I was also wondering, and as you also menioned, is it possible both the leds are defective at the same time?

[dr. d]

I had him replace the old relays and check the wirings prior to installation of the LEDs because they're really, really old. The thing is, it doesn't happen every time I switch from high to low or vice versa. It's quite random. Same as you, the electrician says it's probably the LEDs themselves that are defective when I called to tell him about the issue afterward. But I was also wondering, and as you also menioned, is it possible both the leds are defective at the same time?

these are what i would probably do.

if you still have the old bulbs, and can make the swap fairly easily, which, with the old revo, i believe you can,
do so and see if you have the same problems with the old bulbs.

or, you can replace the current solenoid and see if your problem persists. magkano lang naman ba 'yan? heh heh.

intermittents are difficult to diagnose.
they behave when they feel someone is hunting them down,
then mis-behave again once the hunter loses his patience.

someone once advised me,
electrical contact points are usually kept cleaner, when the power running thru them are higher, because the dirt gets burned off.
with lower power requirements (i.e., LED versus halogen), dirt can build up, causing bad or intermittent contacts.
la lang.

[Menganicoy]

these are what i would probably do.

if you still have the old bulbs, and can make the swap fairly easily, which, with the old revo, i believe you can,
do so and see if you have the same problems with the old bulbs.

or, you can replace the current solenoid and see if your problem persists. magkano lang naman ba 'yan? heh heh.

intermittents are difficult to diagnose.
they behave when they feel someone is hunting them down,
then mis-behave again once the hunter loses his patience.

someone once advised me,
electrical contact points are usually kept cleaner, when the power running thru them are higher, because the dirt gets burned off.
with lower power requirements (i.e., LED versus halogen), dirt can build up, causing bad or intermittent contacts.
la lang.

Thanks for the advice. I'll definitely try it.

[oj88]

It needs further diagnostics.

Does it happen to have H4 bulbs?

H4 configuration has three terminals.... Low, High, and Common. Depending on the vehicle configuration, Common can be either wired as constant +12V or constant negative/chassis ground.

This is a diagram of one that has the Common connected to negative/chassis ground.


In the example above, when you apply +12V to the Low terminal, you get low beam. Applying +12V to the High terminal would give you high beam. If you give power to both Low and High, both low and high beams are lit.

All this to say that either low or high beams will light up without power applied to them. If they do, the most common issues would be:
1. Sticky relay
2. Sticky stalk switch

and much less common:
3. Current could be intermittently "leaking" from the Low terminal to the High terminal internal to the N39. This is either a defect or it may not be 100% compatible in case the vehicle uses a +12V Common. But I think everyone will agree that this is a rare issue, if not, unheard of (at least to me).

[Menganicoy]

It needs further diagnostics.

Does it happen to have H4 bulbs?

H4 configuration has three terminals.... Low, High, and Common. Depending on the vehicle configuration, Common can be either wired as constant +12V or constant negative/chassis ground.

This is a diagram of one that has the Common connected to negative/chassis ground.


In the example above, when you apply +12V to the Low terminal, you get low beam. Applying +12V to the High terminal would give you high beam. If you give power to both Low and High, both low and high beams are lit.

All this to say that either low or high beams will light up without power applied to them. If they do, the most common issues would be:
1. Sticky relay
2. Sticky stalk switch

and much less common:
3. Current could be intermittently "leaking" from the Low terminal to the High terminal internal to the N39. This is either a defect or it may not be 100% compatible in case the vehicle uses a +12V Common. But I think everyone will agree that this is a rare issue, if not, unheard of (at least to me).

Yes, I am using H4.