Front foglight bulb change

[RedCarsGoFaster]

My nearside front foglight bulb has blown and I'm trying to replace it.

I've got the bulb spec, but am struggling to actually figure out how to get into the unit to replace it. The owner's manual is curiously silent on the matter, and the workshop manual I have is for the US, where of course they don't have fog (or something).

I had a bit of a poke around the front of the car at the weekend - there are a couple of screws that don't seem to do much, and a rusty-looking bolt that I can't seem to shift.

Does that rusty bolt hold the whole unit in and the bulb get replaced from behind? Do I just need a torrent of WD40 and a bigger breaker bar?

[Kaz-kzukNA1]

I've already removed the fog light unit from my NSX years ago and the other one I'm servicing at the moment is the face lifted model so without the fog light.

If I remember correctly, there was only one short bolt at the outboard holding the entire fog light body at the vertical bracket. I think I used 12mm socket.

For supporting the inboard side, there is a metal tab attached to the light body and it is inserted to the slit on the lower skirt of the front bumper.

So, after removing the single bolt, you need to slide out the metal tab from the slit while disconnecting the connector at the back.
This will let the entire light assy off the car.
Then, replace the H3 bulb.


Kaz

[RedCarsGoFaster]

Thanks Kaz, that's spot-on. Will get out a bigger set of sockets and a can of WD40!

[Nick Graves]

I managed to replace the side light bulbs from the inside (remove headlight screws and tilt skywards) as the lamp screws are hopelessly corroded.

I don't know if you might reach the fogs in the same fashion.

[RedCarsGoFaster]

Well, it appears I have a different problem.

With the use of a bigger spanner I have released the bolt, removed the fog light unit, and replaced the bulb.

Not only do I not have a working fog light, but now I've noticed that the sidelight isn't working either.

To be honest, not sure if the sidelight was working previously, or if it's something I've managed to disable during my fumblings.

Do they share a common harness somewhere that I might have dislodged? Any other suggestions?

[Nick Graves]

You might have slightly irritated it and either the push-in lamp has come adrift, or promptly blown. I did the latter re-installing a Not an Ashtray lamp in the Leg End.

I'd check the obvious first as co-incidence isn't necessarily causation.

[Kaz-kzukNA1]

When you switch On the front fog light, it will also trigger the tail light relay resulting in both the front side lights and the rear side/tail lights powered up even if the main light sw at the steering stalk was in Off position.
This will also result in cabin illumination being lighted up.

There are several relays and fuses involved but one thing to note is that different fuses are in use for each side of the tail lights.
Very unlikely for all of the small light bulbs at the front and the rear to fail at the same time unless you didn't check them for months.

So, try the obvious thing first.

Put the main light sw in small/side light position.

Check the front side lights as well as the tail lights.

If none of the lights work and you don't see any cabin illuminations, then your issue is either the tail light relay or at the upper stream of it.

If only one side of the tail light works, then check the 2 x 15A fuse inside the pentagonal/octagonal main relay box under the bonnet.

You may as well check the main/dipped beam operation.


Probably something very simple or much more complicated.


Kaz

[RedCarsGoFaster]

You might have slightly irritated it and either the push-in lamp has come adrift, or promptly blown. I did the latter re-installing a Not an Ashtray lamp in the Leg End.

I'd check the obvious first as co-incidence isn't necessarily causation.

Wise words - fingers crossed!


When you switch On the front fog light, it will also trigger the tail light relay resulting in both the front side lights and the rear side/tail lights powered up even if the main light sw at the steering stalk was in Off position.
This will also result in cabin illumination being lighted up.

There are several relays and fuses involved but one thing to note is that different fuses are in use for each side of the tail lights.
Very unlikely for all of the small light bulbs at the front and the rear to fail at the same time unless you didn't check them for months.

So, try the obvious thing first.

Put the main light sw in small/side light position.

Check the front side lights as well as the tail lights.

If none of the lights work and you don't see any cabin illuminations, then your issue is either the tail light relay or at the upper stream of it.

If only one side of the tail light works, then check the 2 x 15A fuse inside the pentagonal/octagonal main relay box under the bonnet.

You may as well check the main/dipped beam operation.


Probably something very simple or much more complicated.


Kaz

Kaz,

With the main light switch in the sidelight position, I get cabin illumination, both tail lights and the drivers side sidelight only.

With the fog light button only, I get cabin illumination, both tail lights, the drivers side sidelight, the drivers side foglight and the rear foglight.

Both dipped beam headlights work, and both main beam headlights work.

The indicators in the front combination lights work on both sides.

I *think* there was a period when I knew the fog light was not working, but that both sidelights were working.

I need to get a long screwdriver, remove the combination light, and check the sidelight bulb.

Fingers crossed that I just have some corrosion on the foglight connector and that it's coincidence that the sidelight has gone . . .

[Kaz-kzukNA1]

Thank you for the feedback.
So, based on what you wrote so far, the relays and fuses are fine and just faulty L-side fog light + L-side small/side light.

Bit too late but I actually found my old blog…

http://www.nsxcb.co.uk/entry.php?544-Preparation-01

http://www.nsxcb.co.uk/entry.php?1136-Final-Touch

You may have rusty GND terminal or intermittent connection somewhere.
If you have multimeter, you can check whether you are getting 12V or not at the connector when the fog light sw is activated.
You can also apply GND and 12V at the fog light unit itself for a quick check.


For the side light in the front combination lamp, you may struggle popping out the lamp assy.

http://www.nsxcb.co.uk/entry.php?9-Quick-Service-on-My-NSX

http://www.nsxcb.co.uk/showthread.php?2166-Releasing-front-indicator-side-light-clusters-help!!!&p=76378#post76378

http://www.nsxcb.co.uk/showthread.php?2166-Releasing-front-indicator-side-light-clusters-help!!!&p=76379#post76379


If the worst comes, you can replace the bulb without removing the lamp assy.
You can access it from behind by removing the head light unit (after removing the head light cover, only 4 bolts to be removed).
Also, may be able to access it by partially removing the wheel arch liner???

Back to the garage now as I'm in the middle of finishing the health check and looking at how to remove the O2 sensor mounted on the 90deg fouler.....


Kaz

[RedCarsGoFaster]

Thanks Kaz, great information as always.

I have a multimeter, so will test the voltage at the connectors when I can gain access.

From looking at the headlight removal instructions, which it sounds scary it only requires the removal of four screws and four bolts - not so bad, if it needs doing!

[Nick Graves]

It's not scary, really.

Lose the cover (that's another four screws) then you'll find four holding the h/lamp to the pop-up frame.

I removed the front two, loosened the rear two and flipped the headlamp up, sort of like a tipper truck.

It gave me plenty of room.

I think I used a plumber's water pump wrench to loosen the side light connector, as it was a bit hard to get sufficient finger purchase on it.

[Pride]

And make sure you use a brand new, high quality very tight fitting screw driver bit, preferably using a "T" driver to remove the headlamp cover screws as they can be excessively tight.

I had a devil of a job undoing mine, they get corroded in place so if you can soak them over night in releasing fluid all the better.

Good luck.

[Nick Graves]

Good point - mine are now decidedly slot-headed instead of chewed.

And only use a JIS-cross-headed screwdriver, not a Phillips.

[RedCarsGoFaster]

Before today I had never heard of JIS screw heads. I will now have Phillips, Posi-drive, and JIS to confuse with one another.

I can see myself acquiring quite the assortment of additional hand tools and replacement fasteners doing little jobs like this . . .

[RedCarsGoFaster]

Well that was an adventure.

The extra long screwdrivers I'd ordered were actually too long to get under the bumper to get to the combination light release screw (d'oh), so I went directly to the headlight removal to access the sidelight. Really very straightforward - in the end I used a mini ratchet set with a PH2 head to (very carefully) break the initial torque on the headlight cover screws and used the car's toolkit screwdriver from then on. Have some JIS screwdrivers coming for the next time.

The sidelight had indeed blown because I looked it at funny, so with a new bulb it's back to working order. I have no fear of replacing it through the headlight in the future. :)

The fog light turned out to be a bitch.

The problem was that the earth connector had broken between the crimp and the female socket, leaving the socket attached to the light housing. First time round I'd assumed there was only one wire and that the bulb earthed itself through the body of the fog light housing, which in hindsight was a fairly rudimentary error.

The connectors are a standard size, so I nipped down to Halfords to pick up a box full . . . and thus began a deeply frustrating afternoon.

Snipping the body of the old connector off: easy.
Crimping a new connector onto the tiny length of cable buried deep within the rubber boot on the back of the fog light: fiddly, but OK.
Ensuring that the new connector was connected to the body of the fog light, successfully coaxing the fog light into position, and then ensuring that the rubber boot was securely attached to the back of the unit: bordering on impossible.

Every time I tried to get the boot seated there would be a little ping as the connector let go of the earth wire. What felt like twenty connectors later I gave up and reinstalled the fog light without the boot, which by this point had split anyway . . .

The next time that fog light bulb blows the car will be going to the garage so someone else can worry about it - in order for bulb changes to be swift and efficient (at least for my fists of ham) it's going to need a couple more inches of cable splicing in for leeway, and a new rubber boot.

Anyway. Lights all working again. For now.

[Nick Graves]

Well, you got there in the end!

Those rubber boots are best soaked in something like Holts silicone & rubber lubricant for a while. It restores pliability and does make sliding things in a lot easier. Cleans them up a treat, too.

PS - I did something similar when I removed the Leg End's front bumper and didn't realise how short the loom to the temperature sensor was. Having broken the wire, my cack-handed attempts to extend the loom with crimps and speaker wire took longer far than did the pop-up bonnet sensor re-alignment itself...

[RedCarsGoFaster]

Well, you got there in the end!

Those rubber boots are best soaked in something like Holts silicone & rubber lubricant for a while. It restores pliability and does make sliding things in a lot easier. Cleans them up a treat, too.

PS - I did something similar when I removed the Leg End's front bumper and didn't realise how short the loom to the temperature sensor was. Having broken the wire, my cack-handed attempts to extend the loom with crimps and speaker wire took longer far than did the pop-up bonnet sensor re-alignment itself...


Good tips!

Postscript to this story - I was unburdening myself of this ordeal to a colleague this morning and they made an astute observation.

"Incandescent bulb?"
"Yes."
"So why not swap the wires around so that the long tail on the bulb goes to the shorter wire of the connector, and the longer wire of the connector goes to the light housing?"
" . . . because I was slavishly putting it back together the way I took it apart without engaging brain."

My colleague is a smarter man than me. I'm sure there's a lesson here . . .

Now to determine whether I can face taking the fog light out again, just to put it back the way it probably always should have been . . .