Failed MOT - driver side headlamp

[Bonners]

Ok have booked my car in with my mechanic on Dec 9th so will hopefully learn more then.

Upon explaining the issue over the phone it struck me that maybe I’m not fully comprehending the issue. Mine is a UK car, with the rotary knob in the cabin to adjust beam height. So even though I’ve never touched the rotary knob for s9me reason, capacitor drain suggested, the motor used to activate the lamp is spinning. As the beam isn’t moving I guess this means the motor assembly has disconnected itself from some mechanical linkage.

If I can reconnect it, is it the mechanical linkage that acts as the shut off to stop the motor? Thanks guys.

[RedCarsGoFaster]

Ok have booked my car in with my mechanic on Dec 9th so will hopefully learn more then.

Upon explaining the issue over the phone it struck me that maybe I’m not fully comprehending the issue. Mine is a UK car, with the rotary knob in the cabin to adjust beam height. So even though I’ve never touched the rotary knob for s9me reason, capacitor drain suggested, the motor used to activate the lamp is spinning. As the beam isn’t moving I guess this means the motor assembly has disconnected itself from some mechanical linkage.

If I can reconnect it, is it the mechanical linkage that acts as the shut off to stop the motor? Thanks guys.

That's not quite the problem . . .

The problem (probably) is that the capacitors within the control circuit attached to the motor have failed. This usually means they have leaked their contents over the circuit board to which they are attached. Depending on stage of damage, the electrical circuit could be repairable just by replacing the capacitor (i.e. the only problem is that the capacitor is not functioning as intended within the electrical circuit), but the leaked capacitor contents tend to corrode the other elements of the circuit board, even down to the copper tracks that pass electrical signals over the surface of the board.

It sounds like the control circuitry in one of your headlight adjust motors has failed on (so it will run forever), and the other one has failed off (so it won't run at all). Worth checking if the symptoms you see change depending on whether the control knob is turned to the 0, 1, or 2 position.

This is unfortunately a common problem for 90s cars that use this kind of capacitor on circuit boards. You might be alarmed to know that this type of failure can happen in several areas on the NSX - two of the most common areas for it are the climate control unit and the radio.

Kaz and Heineken both have blogs discussing repair of this kind of failure to a radio circuit board - see link below for one that Kaz posted recently:

http://www.nsxcb.co.uk/entry.php?272...ra)-service-01

http://www.nsxcb.co.uk/entry.php?272...ra)-service-02

[Bonners]

RCGF, many thanks for your input and attaching the links, and apologies for the delay in responding, crazy end to the year!

Finally, I now understand what you chaps mean, both re my specific problem and the general issues related to the NSX electronics. I guess I’ll need to do some reading and see removal of these circuits is even remotely possible for someone like me, or even at the local garage.

Assuming the issue is indeed circuit board related, i don’t suppose buying a new headlamp assembly, as suggested by Honda, is likely to make any difference.

I hope everyone had a merry Christmas, and all the very best for 2023.

[L696ULO]

To stop the motor whirring you can quite easily disconnect the centre console switch.
I have a 1993 NSX, open the centre console compartment, lift the bottom cushioned plate using a small flat head screwdriver at the front middle. That should reveal 4 screws, undo and the compartment will lift out, push the height adjuster button from underneath then undo the centre screw holding the console that should give enough space to disconnect the blue connector to the switch.
Here’s a thread which shows the capacitor circuit board and other info. If the link doesn’t work use the search bar and type headlight height adjuster (the thread is either 2019 or 2019)


http://www.nsxcb.co.uk/showthread.ph...ight-adjusters






http://www.nsxcb.co.uk/showthread.php?15725-UK-spec-pop-up-headlight-height-adjusters

[Nick Graves]

I'd disconnect at the headlamp end and replace the switch with a blank.

Pretend it's JDM Yo!

I think it's the 'needs to function where fitted' thing. And it's not as if you regularly carry a few bags of builders' dust in the boot at night.