Electric motor type noise?

[m666 edd]

When I last drove my car I noticed an electric motor type whine from under the bonnet. It makes the noise whether the key it just turned without starting the car or when it is running and even after a drive.

I hope Kaz doesn't mind me using one of his photos to show whereabouts I think the sound is coming from:

http://www.nsxcb.co.uk/attachment.php?attachmentid=8459&d=1296087461

It seems to be coming from the black box which is left of the brake fluid reservoir and above the abs fluid reservoir on the photo.

I don't think I've noticed this noise before so was wondering what is causing it. It's not mega loud or anything but just continuous.

It's not the ABS accumulator sound as that is very distinct and noisy and I've recently given it all a good flush so I know that is in good working order.

[Nick Graves]

That's your DBW throttle rheostat box.

Take the lid off (two bolts) & see what's going on.

All I can think of is your throttle cable is so loose, it's resonating like a guitar string. Be careful it doesn't produce bosons or fermions - it might all get a bit weird.

Or maybe the rheostat has a loose winding, causing the resonance. Seems a bit unlikely.

I'd say it's far more likely to be either the HVAC fan or the ABS module. Or even PAS! Sounds can travel in weird ways round a momocoque just to fool you.

[markc]

That's your DBW throttle rheostat box.

Isn't that the Cruise Control actuator? Does your cruise control work properly i.e. smoothly, quickley etc?

Cheers

Mark

[NSXGB]

Ed's car is non DBW. Definitely the cruise control module though.

[AR]

That's your DBW throttle rheostat box.

Take the lid off (two bolts) & see what's going on.

All I can think of is your throttle cable is so loose, it's resonating like a guitar string. Be careful it doesn't produce bosons or fermions - it might all get a bit weird.

Or maybe the rheostat has a loose winding, causing the resonance. Seems a bit unlikely.

I'd say it's far more likely to be either the HVAC fan or the ABS module. Or even PAS! Sounds can travel in weird ways round a momocoque just to fool you.


OP's car is J reg IIRC, so either abs or aspirator fan.

[m666 edd]

Just went outside to listen to it again now that it's nice a quiet outside and narrowed it down to the drivers side headlight. I think it's the headlight motor continually doing something.

The light flip up and down perfectly fine and setting the adjusters inside work fine with a very slight change in pitch to the sound but that's probably voltage related. I'll try and disconnect the motor for that side to be sure.

[AR]

You sure is not the abs pump/accumulator?

[Kaz-kzukNA1]

If the ABS accumulator pressure drops beyond the threshold, the ABS pump will be activated only after the controller sees 6mph so very unlikely to be the cause of this noise unless the owner has signal interference on the wheel speed sensor. It happened to one of my wheel speed sensor in the past.

Have you removed your centre console recently or in the past?
The noise could be from the headlight level adjuster.

There is very little play in the cable under the adjuster switch at the centre console behind the shift lever.
Due to the design of the connector and circuit board, you can actually pull out the connector housing slightly without noticing it if you lifted the rear end of the centre console too much before unlocking the mating connector.

This will result in intermittent connection at the male/female terminals inside the connector and it will operate the head light level adjuster randomly whenever the IG key is in ON position. I think it can happen regardless of whether the headlight is On or Off.
[Edit: From outside, you can’t see this because the male and female connectors still perfectly locks each other even if the male side housing under the switch is pushed outwards a little.]

If that is the case, just remove the switch and push the connector housing back so that the male terminal sticks out far enough to make good contact to the mating female terminal.

Same thing can happen on the head light pop-up switch just below the right side of the dash.

Obviously, it could be completely something else.....

Kaz

[m666 edd]

Definitely not the ABS accumulator as I've had enough experience with it when I flushed/exercised the solenoids etc. That's a hard sound to confuse! At this stage I'm only turning the key and not starting the car anyway.

I personally haven't had the centre console apart but I do think it is probably what you say. I have however been continually moving seats in and out of the car from both sides so maybe the centre console being knocked may have loosened it.

If I use the headlight level adjuster I should hear what is the continual noise (on the drivers side) briefly on the passenger side, just to get confirmation before taking apart the centre console?

[m666 edd]

I took out the centre arm rest and was able to look in at the connectors. They all seem to look fine and got my fingers in there to give them a push but this didn't sort the problem.

I unplugged the connector on the back of the light which controllers the headlight level adjustment and this stopped the noise. The lights flip up and down fine still so I definitely unplugged the level adjuster.

I don't suppose anyone has a photo of the connectors etc under the centre console? I don't really want to take it all apart if I can help it.

[Hagasan]

Ed,here is what you will find under the console. Ignore the extra blue connector with the "flying leads". was using this for some testing....You might want to check the continuity from the switch back connector to the 6P plug that then connects to the headlights and aim motor, not the other 6P which is just for the motor lift function. May have a less than perfect earth. Hope it helps.Gary

Also see page 7 on the .pdf...or read it all!!



11116111131111511114



I took out the centre arm rest and was able to look in at the connectors. They all seem to look fine and got my fingers in there to give them a push but this didn't sort the problem.I unplugged the connector on the back of the light which controllers the headlight level adjustment and this stopped the noise. The lights flip up and down fine still so I definitely unplugged the level adjuster.I don't suppose anyone has a photo of the connectors etc under the centre console? I don't really want to take it all apart if I can help it.

[m666 edd]

Cheers Gary, that should help.

When I get some time I will take the centre console apart to check. For now I can at least disable the motor easily.

[Kaz-kzukNA1]

Hi, m666 edd.
In your check list, please add the following point based on my past experience.

For this switch, you don’t need to remove the centre console.
As you have already removed the arm rest, you can access it from the opening under the centre console.

While holding the surrounding area of the switch with your hand, use the other hand to push the switch up from the bottom.

Once it’s out, check for the blue connector housing.
This is what I meant in my original post.


..............
Due to the design of the connector and circuit board, you can actually pull out the connector housing slightly without noticing it if you lifted the rear end of the centre console too much before unlocking the mating connector.

This will result in intermittent connection at the male/female terminals inside the connector and it will operate the head light level adjuster randomly whenever the IG key is in ON position. I think it can happen regardless of whether the headlight is On or Off.
[Edit: From outside, you can’t see this because the male and female connectors still perfectly locks each other even if the male side housing under the switch is pushed outwards a little.].........



https://lh6.googleusercontent.com/-IJJW3Nw6A20/T3b4waUakXI/AAAAAAAABao/YrxvT0v0zJk/s640/IMG_0001.JPG
The blue connector housing should only stick out just a little from the switch body.



https://lh5.googleusercontent.com/-lifhnmzI1tQ/T3b4w9-LH7I/AAAAAAAABaw/SS1uZAexnNk/s640/IMG_0002.JPG
To be 100% sure, just remove the thin film like lid at the bottom and look at the gap between the connector housing and the circuit board indicated by the arrow.

There should be no gap at all.

If there is any gap, from out side, it looks everything is perfectly connected as both the male and female connectors are locked properly yet inside the connector, the terminals are not engaging properly resulting in intermittent connection.

This made the random operation of the headlight adjuster on some of the NSX in the past.

Kaz

[m666 edd]

To be 100% sure, just remove the thin film like lid at the bottom and look at the gap between the connector housing and the circuit board indicated by the arrow.

There should be no gap at all.

Having just taken the switch out I can confirm that the blue connector is on right against the circuit board with no gap.



Edit: Also to clarify the problem isn't intermittent it is constant on the drivers light only whenever the ignition is on whether the engine is running or not. This now leads me to believe I need to have a look at the "HEADLIGHT ADJUSTING MOTOR DRIVING CIRCUIT" on the drivers side.

[madras]

Hi M666 edd,

did you resolve this problem. I have the exact same issue, just the drivers side motor going (the passenger side still adjusts up and down with the dial). Pulling the connector out stops it. The blue connection is perfectly flush with the circuit board and the connect seems clean and fits in perfectly.

Is the problem just with the switch that Kaz pictured in which case I can get a new one or elsewhere?

many thanks,
Chris

[Kaz-kzukNA1]

Hi, Chris.

If the SW is fine, then you may want opening the motor itself.
Never tried before but I read somewhere on FB or maybe Prime that there was leaky capacitor causing the same issue. Not sure this is the cause of your issue but worth a try.

Kaz