Bright Headlight Dash Light

[Duffman]

I have switched all of my dash lights to LED with success, with everything working correctly, but the bright light symbol does not light up.  I have switched the bulbs between LED and incandescent and it still does not light up.  I probably need to check and see if I have a ground issue, though it is difficult to reach behind the dash.  Other than a ground or power issue, could there be an issue with the turn signal switch that is impacting that particular light?

Appreciate your assistance!

[Yarb]

@SteveJ

[Yarb]

You didn’t tell us what series car you have

[SteveJ]

7 hours ago, Duffman said:

I have switched all of my dash lights to LED with success, with everything working correctly, but the bright light symbol does not light up.  I have switched the bulbs between LED and incandescent and it still does not light up.  I probably need to check and see if I have a ground issue, though it is difficult to reach behind the dash.  Other than a ground or power issue, could there be an issue with the turn signal switch that is impacting that particular light?

Appreciate your assistance!

I believe the circuit is pretty much the same for all S30s. The power for the high beam light comes off the fuse for the right headlight (red wire). It comes to the high beam indicator bulb, and on the other side of the bulb, you have a red/white wire that goes down to the high/low beam switch. In the high beam position, the red/white wire for that bulb and for the headlights is grounded.

Things to check off the top of my head:

1. Make sure the right headlight fuse is good.
2. Make sure the bulb is seated properly in the socket.
3. Make sure the socket is seated properly in the gauge. If you don't want to remove the speedometer, I have had good luck in the past removing the tachometer to get to the bulbs behind the speedometer.

Are there any modifications to the wiring that we should know about? Are the headlights coming on and switching properly between high and low beam?

[Duffman]

Yarb, I have a Series 1, have manufacture date in my signature.

SteveJ, thank you for your thoughts, I will check those areas of potential concern.  The headlights work fine and do switch properly between high and low beam.  No electrical doctoring or mods done on wiring.  Like your idea of getting to back of the back of speedo by removing the tach, may be a challenge either way as the dash has been recovered and everything is a tight fit.

As everything else works, still think it is a fitment issue with bulb and socket but will let you know (will doublecheck the fuse!)!

Appreciate the response!

[SteveJ]

With unmolested wiring, it's unlikely to be the fuse unless the right headlight is dim. (Note: This only applied to sealed beams and halogens.)

Some LEDs don't have polarity set right, but since you said the incandescent bulb didn't work either, it's not likely a polarity issue.

[w3wilkes]

You mentioned LED. They're the equivalent of a one-way valve and will only pass power in one direction. Any possibility it's a direction issue with the bulb? Can the connector wires be reversed?

[Duffman]

Wilkes, I have not touched the wiring to this particular bulb, so don't think it is a problem.  Looking to attack this problem this next week, will report back!

[w3wilkes]

The reason I mention about LED's is because of the way the headlights are wired from the factory. When I went to LED headlights I had to either use the included "anti-flicker" device that came with my LED headlights or put in the Headlight relay upgrade Harness sold by MSA which I've now done. I created a thread that describes the way Datsun wired the headlight circuit vs the way it's changed with the plug and play upgrade harness originally created by @Zs-ondabrain. Since the diagram doesn't show where the high beam indicator is in the circuit it may be that power goes through that connector the "wrong way" for an LED bulb. Here's a link to the thread;

 

Edited December 26, 2022 by w3wilkes

[qz16]

Duffman,

If your headlights switch from low beam to high beam, then the switch is not likely to be the problem.  Likewise, if the headlights switch then the relay is likely to be good as well. 

If you can switch the high beam indicator bulb from led to incandescent, then you can get to the socket.  Can you put a multi-meter on the wire going to the socket and the other end of the multimeter to ground and see if there is 12v?  Don’t forget to try it with the high beam switch in both positions.  If there is 12 volts then it probably is a grounding issue.  When the socket is installed in the speedometer it is grounded.  If it is not firmly installed into the speedometer then you might not get a ground to the socket.  If you do not have 12v in the lead to the socket then I think the problem gets a bit more insidious.  Its been a while but I think that function goes through the combination switch.  If necessary, I can dig out the schematic, but I would check the voltage to the socket first.

regards,

q

[SteveJ]

23 minutes ago, qz16 said:

Duffman,

If your headlights switch from low beam to high beam, then the switch is not likely to be the problem.  Likewise, if the headlights switch then the relay is likely to be good as well. 

If you can switch the high beam indicator bulb from led to incandescent, then you can get to the socket.  Can you put a multi-meter on the wire going to the socket and the other end of the multimeter to ground and see if there is 12v?  Don’t forget to try it with the high beam switch in both positions.  If there is 12 volts then it probably is a grounding issue.  When the socket is installed in the speedometer it is grounded.  If it is not firmly installed into the speedometer then you might not get a ground to the socket.  If you do not have 12v in the lead to the socket then I think the problem gets a bit more insidious.  Its been a while but I think that function goes through the combination switch.  If necessary, I can dig out the schematic, but I would check the voltage to the socket first.

regards,

q

Actually that is not correct. The socket for the high beam indicator is not grounded on the gauge like the gauge lights. It has two wires as I described in post #4 on this thread. It would more likely be the connector not plugged in completely between the dash harness and the socket.

[qz16]

Steve J,

Thanks for the correction.  Still think it would be a good idea to see if there is 12 volts on that pair of wires, before going any further.  Thanks again steve J
I just thought of this, and yes, I know it is silly, but are you sure that the bulb that is not lighting is actually the high beam indicator or is it possible that it is something else?  Is there any other bulbs that are on?

Edited December 26, 2022 by qz16