Today happened something I've never thought would ever happen...

[goldnsx]

Before I go into details I'll let you guess what happened today while driving. Hint: it really pissed you off.

[britlude]

you spilt your extra large McDonalds thick strawberry shake over your interior??

[NSX 2000]

Somebody doing 40 in the fast lane with nothing in the slow lane, actually pulled over and let you pass.

Sorry that would make you happy!

[NSX 2000]

Somebody fitted pop ups to a non pop up NSX?

[NSX 2000]

Somebody fitted a VW 2 Litre Diesel to an NSX, now that would make my blood boil!

[NSX 2000]

Sepp Blatter was spotted driving an NSX whilst handing out brown envelopes?

[NSX 2000]

You saw a child in the passenger seat of an NSX eating a toblerone, and putting their sticky fingers evrey where?

[NSX 2000]

You saw somebody washing their NSX with a bucket and sponge, and the bucket didn't have a grit guard?

[goldnsx]

Thanks for the (wild) guesses, it made me smile a little bit after todays hell trip. I could have waited a little bit longer to reveal the story just for the purpose of amusement but here it goes:

It was sunny day (with some rain in the afternoon the forecasts predicted) and I was going on a road-trip. All went fine until the engine suddenly went out. Restarting it while trying to keep momentum was refused by the engine itself. I was doing 50 mph and it was going a little bit downhill with no traffic. So I had the choice where to park it at least. I parked it at a restaurant which was closed I saw later but a women in the restaurant saw that I was in big trouble so she opened the door. I was hungry, thirsty, angry, depressed, though guessing, checking and organising all at the same time. I've called 'AAA' (the US guys say) or the 'road help' and had to explain them 10x where I'm left stranded. Their help was promissed within 50 minutes, so I had enough time to check what was wrong. The starter turned but it seemed to be fuel or ignition related. As I have a Supra pump which is known to draw a lot of current (16-20 A) and the SoS wiring kit I checked the 40A fuse in the engine compartment which looked fine. I began to dismount the rear of the interior to get access to the wiring. Thanks god that I've reinstalled the toolkit again after my crazy weight-saving excesses. :) I checked several things but had no multimeter in the car (which will be for the rest of my life added to the toolkit for sure, source: China, 15 bucks). It took some time until I saw something 'fishy'. That was the connector of the SoS relay that is in the wiring kit. It looked some kind of deformed/melted so I thought I was on the right track. Until then the pros of the road help arrived, two friendly guys with a 'forbidding' trailer whichs looks gave me even more intention for find the problem. 'Forbidding' in the meaning that I wanted to avoid being trailered if possible. I've asked him for a multimeter and we saw that there was no voltage at the fuel pump while its resistance (not the resistor) was ok. 5 minutes later he created a wire to bypass the bloddy SoS relay and we tried to start the car: HORRAYYYYYYYYYYY! I was able to made my way home (thanks to the retardement now WITH rain as predicted) and parked the car in its safe storage place. I had to pull the wire to the fuel pump by hand as it's now running constantly.

Never ever did I think that my car will ever let me down. Hondas can't break, no? At first, I was very disappointed and thought about selling the car to the next guy who passed me. Good for me, noone came by and made me an offer. That's a good thing with broken cars as nobody wants to deal with them. :) I'm also glad that not many cars passed, so the shame on Honda can't be read in tomorrows newspaper. In the next days I'll have a look what happened exactly. The guys of the road help were a little bit surprised to meet a guy who was well informed about the car. Without extensively DIYing I would have been left stranded with an unsure outcome (and bill of course). To be honest: it's not Hondas fault but the fault of the bloddy aftermarket crap. So the headline in the news should not be 'a Honda broke down' but much more 'a tuned car with aftermarket crap left his driver stranded with justice'. :) It seems as if the relay was able to hold 20A but not the attached wiring. I'll do some pics of it.

I'm still a little bit puzzled and it will take some time until I gain some confidence again to drive her. But now I understand why many exotics can't be seen on the road because it really pisses you off big time being left stranded out in the desert.

EDIT: does anybody know the best quality relais (or what to avoid)?

[dcnsx]

Somebody fitted pop ups to a non pop up NSX?
Worse still, the other way round! ;)

[Kaz-kzukNA1]

..............................................
EDIT: does anybody know the best quality relais (or what to avoid)?
Hi, goldnsx.

I don't know how your fuel pump is controlled (simple continuously On/Off while the engine is running/stopped or PWM, etc) and also don't know the spec of your aftermarket fuel pump (current rating at specific pressure, rush current, etc).
The current consumption changes with target pressure.


You can find mechanical high current capacity relay from Tyco, Omron, Panasonic, etc in different style (if selected plug-in style, it will have huge spade terminal at the load side).
I use it when upgrading the EPS controller on our NSX with 70A rated one.
Probably the cheapest and the easiest although life would be shorter than the remaining two options below.


You could design simple circuit using suitable MOS FET.


Or, if you have enough space (like the size of your palm) and don't mind extra cost, you can go for the DC SSR in panel mount style.
You can find SSR from many manufactures but Crydom, Omron, etc are good ones.
As NSX uses aluminum frame, it's perfect for heatsink but you don't want drilling the panel so just fabricate aluminum plate and mount SSR on it to meet the heat dissipation spec for your current consumption and temperature.
Or, just buy the readily made heatsink from the SSR manufacture although you need to think about its shape/size.


Regardless of which one you select, please add flywheel diode near the load side of the relay if you are driving the inductive load like electrical motor used inside the fuel pump.
Without it, it could shorten the life of the contacts on mechanical relay especially if it's NC type or it could even destroy the electrical circuit inside the FET/SSR.
No need to say the importance of using good quality thick gauge wire for such high current application.


If you don't understand what I'm talking about, just find some local electronics company/shop who designs circuit board.
Very simple circuit and not expensive (except for the SSR) so just tell them it's for driving motor powered fuel pump and they should be able to help you.


Kaz

[goldnsx]

Hi Kaz

I use the Supra pump with these specs: http://www.superstreetonline.com/how-to/engine/1405-fuel-pump-shootout-part-2/ (scroll down 2/3). It's loves current (its only downside): 16A at 40 psi which goes up to 20A under higher load the CTSC demands (80-90 psi). I'm running it at about 13.8 V. The power is supplied from the fuse box in the engine compartment. The added relay switches the fuel pump on/of by the main relay the car already has. Wiring is 4 mm2, more than needed as 2.5 mm2 would have been sufficient. 4 mm2 all the way down to the fuel pump, also inside the fuel tank.

Thanks for your suggestions. I'm going the easier way and replace the relay with a good one. I've found this one: http://www.conrad.ch/ce/de/product/504021/Kfz-Relais-12-VDC-40-A-1-Schliesser-Kraecker-15120010?ref=searchDetail The special feature of this its much higher max. voltage it can handle: 75 V/DC. Cheaper relais have a max voltage of 14 V (while my pump is feeded with 13.8 V).

From what I've seen is that the connector of the relay got melted to some point at one terminal. I don't think it had a problem with the contact itself (higher resistance) as it was sitting very firmly. I think even more that the relay itself got hot at the terminal and 'sent' the heat down to the connector.

I've a second problem since this escapade. My brake warning light is now light on but only by about half of the illumination. It also flickers a little bit When I pull the handbrake lever it's lights on by 100% intensity. I've checked the schematics and guess that it has ground somewhere. Just another 'construction area' I'll have a deeper look into tomorrow...

[Kaz-kzukNA1]

Hi, goldnsx.

When selecting the wire gauge/size, normally, you would put 100% (twice) the safety margin at the highest possible operating temperature.
The cable length should not be a problem as it's only from the bottom of the fuel tank to the engine fuse box but the cable temperature does matter.
In Japan, JAF (similar to TCS) carried out detailed testing and it confirmed that the cabin temperature could exceed 80degC if parked under the sun in hot summer.
Personally, I would go one size thicker on the gauge size to double the safety margin.
Please make sure to check the wire temperature before/after running the pump on hot summer day.

There was no performance graph on the data sheet for the relay so can't really comment on the suitability but seems like being used by other automotive manufactures so should be fine.
Max switching voltage/power is the contact performance that can safely switch on without disturbing other relay spec so even with the 14V one, (although one won't use it in this configuration) you could apply much higher voltage but with significantly reduced current rating. This is the reason why you need to check the performance graph and not just the written spec.

I believe you are referring to the 'parking brake indicator' (red big circle marker) when you mentioned about the 'brake warning light' and not the 'BRAKE LAMP' warning light at the centre bottom of the dash.

On European model, I think I saw similar thing when I disconnected the tail light assy but can't remember whether it was both or just the right side.
It doesn't happen with the JDM tail light assy.

I'm not confused but I agree, it sounds very strange to talk about 'parking brake indicator' and not the 'BRAKE LAMP' warning when discussing about the tail light assy.

You may want to check the connectors inside the boot especially the 22pin one at the forward left side of the boot behind the carpet.
If you have ever experienced condensation inside the boot or at the tail light assy lens, part of the female terminal could broke off at multiple connectors causing intermittent continuity or increased resistance.


Kaz

[Kaz-kzukNA1]

Just read your post on Prime.
As same as Mac Attack's comment, please do not use soldering when connecting wire to the terminal where it can see vibration.
While your melted connector housing issue seemed to be triggered by the not sufficient relay spec, the cracked solder joint could accelerate the failure.
Please always use crimping with suitable tool to control the crimping pressure.
On certain engine dyno, even with the MIL spec connector using the special crimp terminals, the dyno loom had to be replaced after just 1 year as some of the connectors couldn't be secured against the massive vibration generated by this engine.
Some of the owners who upgraded their ABS to the latest spec experienced wiring issue as they were using the ABS upgrade loom with wires soldered to the terminals under the heatshrink tube at the white connectors.

Kaz

[goldnsx]

I finally have some pics.

13043 13044 13045 13046

The relay doesn't look to bad (to me). When I closed it manually I got around 0 Ohms but any resistance is bad. The femals plug is melted at the one to the fuel pump and the pin at the relay itself looks to be melted a little bit.

[goldnsx]

More pics.

13047 13048

Wiring

The SoS kit comes with 12ga (3.3 mm2) which is sufficient for the Supra fuel pump. From the relay to the fuel pump I use 4 mm2 as the engine compartment is warmer than the interior (I never park in the sun). The AAA guys used a 2.5 mm2 extension as a quick fix and testing them for getting hot the SoS 12ga doesn't get warm while the 2.5 mm2 gets a little warm, maybe 30 deg C.

I'll disassemble the relay connector completely and won't (can't) reuse it. Then we'll see more.

Parking brake indicator

Problem solved here. I've installed a Smart shift light from Züblin years ago. It gets fed form the failing realy but by a separate fuse in the fuse block. The parking brake indicator lights up whenever the rpm is over 7600 rpm. I've removed the wiring for the connection of the Züblin to connector below the hand brake level and the brake light indicator works as usual (no semi-lightened and flickering anymore). I still have a beeper as a warning for over-reving.

Next week

I'm going to order a new relay and connect the wires directly to the relay. I'll redo the connectors if needed.

One sidenote

While testing I was not sure if the famous main relay was bad. I had a spare one (resoldered) and tested this too. Not sure if one of them was bad or if the current supply to the main relay was faulty because I didn't get always power when I thought it should have. I know that IGN only supplies for 2 seconds if you don't start the car.
Just wondering: both main relays are about 12 years old. Does soldering solve the problem or do I run into other issues in the future like bad contact?

[goldnsx]

Both terminals show sign of heat, one more than the other. So the relay went bad.

1305013051

[goldnsx]

I've received the new relay today. With new wiring, the car now runs. At 20 deg. C ambient the relais gets a temp of around 45 deg. C at the hottest point with the car idling for half an hour.

[goldnsx]

I've found some more relays to fix (preventative): Dimmer control unit, Cooling fan control unit, headlight control unit. Also checked to cold soldering joints and resoldered some fishy ones.

13067 13066 13068