Power Door Lock Delete?

[Honcho]

On my S Zero quest, I came across a post in the legendary weight reduction thread from [MENTION=18976]Sudesh[/MENTION] that mentioned the NSX-R deleted power locks and replaced the switches with plastic blanks. Since my doors are gutted for paint and the NSX keyless system is primitive at best, I looked into this further and found that the NA1 Type R did indeed use a different, manual door lock system. The part numbers are 72110-SL0-J11 and 72150-SL0-J11. Rather than spending $300 bucks for the pair, I was wondering if it was possible to convert my existing door latches to "powerless" versions. From the parts diagram, it looks like the R part has just one harness for the door switch. If I clip the other harnesses, is it possible to remove the door lock motor from the assembly as well? Has anyone tried this?

 

[MotorMouth93]

There are some photos here that look like the motor assembly could be removed. https://ahparts.com/buy-used/2004-a...k-actuator-72110-sl0-a03-72110sl0a03/299892-1

 

[Honcho]

There are some photos here that look like the motor assembly could be removed. https://ahparts.com/buy-used/2004-a...k-actuator-72110-sl0-a03-72110sl0a03/299892-1

Thanks- it looks like I may be able to just pull the motor and the harnesses will come out with it. I have to dig up my door latches to mess around with them. They're in a box here somewhere...

 

[Old Guy]

I presume you are also deleting the security system because in addition to the door switch there are switches in the latch which appear to be in the same connector as the lock motor. Those switches (knob switch and cylinder switch) are required for the operation of the security system.

Since you seem a little obsessive with parts renewal, consider that there have been very infrequent reports of failure of the latch internals on high use cars. This failure makes it impossible to open the door. I can't remember the year of your donor car; but, I know it is na1. If the donor had a lot of use, replacement of the latches might not be a bad idea. While infrequent, latch failure is a miserable repair because the repair requires removal of the seats and partial sacrifice of the door liner components (or complete sacrifice if you are unlucky) to get at the back of the latch to facilitate its chop-up and removal. If you are doing the no expense spared thing, a pair of fresh non power latches for $300 is not such a big expense.

 

[Honcho]

I presume you are also deleting the security system because in addition to the door switch there are switches in the latch which appear to be in the same connector as the lock motor. Those switches (knob switch and cylinder switch) are required for the operation of the security system.

Since you seem a little obsessive with parts renewal, consider that there have been very infrequent reports of failure of the latch internals on high use cars. This failure makes it impossible to open the door. I can't remember the year of your donor car; but, I know it is na1. If the donor had a lot of use, replacement of the latches might not be a bad idea. While infrequent, latch failure is a miserable repair because the repair requires removal of the seats and partial sacrifice of the door liner components (or complete sacrifice if you are unlucky) to get at the back of the latch to facilitate its chop-up and removal. If you are doing the no expense spared thing, a pair of fresh non power latches for $300 is not such a big expense.

This is why I love this forum. I thought, for some reason, that the alarm setting switch was pinned in the same harness as the door open switch. I'll check the ETM to see for sure. While I am implementing other, more robust security measures in this car, I would like to keep the OEM system. I checked the JDM parts catalog and, lo and behold, the NA1 NSX-R did NOT come with a security system! Though, if you consider the crime rates in Japan, maybe that wasn't much of an issue. Also, my NSX has the ultimate anti-theft system for 2020: a manual transmission. Looks like I have some more research to do.

 

[Old Guy]

The 1991 service manual shows the following pin out

View attachment 166500

If all you want is the weight saving associated with the motor removal you could probably de-pin 7 and 8 which should allow you to remove the motor without mangling the plug. The bigger issue is that the diagram implies that the lock knob switch might be mechanically integrated with the motor mechanism. Until you get eyes on the latch you won't know whether you retain the switch operation after the motor is removed. Loss of the latch switch might not be a big deal. The security system and the door lock module are interconnected. You would need to check the interconnections between the two systems. You might just lose the relock function or the security system may not arm depending on whether it takes its arm signal from the knob switch or the key switch. Careful perusal of the lock and security module schematics and test procedures may allow you to figure out the specific functions of the knob and key cylinder switch.

I have never had an issue with either system so I have not bothered to investigate them in detail. The closest I have got to medalling with the latch was unplugging it so I could access my window regulator when I did my Hugo kit install.

 

[drew]

Can either of you take some photos of the switches? Can the contacts be cleaned?

I am pretty sure the cause of the alarms inablity to arm or unwanted activation is the result of poor switch contacts. I ran across this recurring issue with researching the Keyless units.

 

[Honcho]

Can either of you take some photos of the switches? Can the contacts be cleaned?

I am pretty sure the cause of the alarms inablity to arm or unwanted activation is the result of poor switch contacts. I ran across this recurring issue with researching the Keyless units.

I'll snap a few for you. Once I figure out which box they are in LOL. This is a common issue. I may just de-pin the motor from the harness as [MENTION=26435]Old Guy[/MENTION] suggests. Need to do some ETM research, but real life is getting in the way right now.

 

[Honcho]

Managed to get one of the latch units apart to further investigate this idea. The motor unit appears to be connected to the door latch using pressed-in components, so it looks like I won't be able to separate it from the housing without damaging it. Secondarily, I cannot see how to safely remove the security switch, let alone separate it to clean the contacts. There is a press-fit latch connection to the switch that will almost certainly shatter if I force it. Any tips from anyone who has done this?

 

[RYU]

man... every time I see a thread with photos like this i'm truly amazed that after ~30ish years those things still work for the most part.

 

[Honcho]

man... every time I see a thread with photos like this i'm truly amazed that after ~30ish years those things still work for the most part.

Look how clean the motor housing is on the inside- that thin black line is a rubber gasket! It's amazing how much thought and attention to detail Honda put into this. After I wipe this unit down with a microfiber, it will probably work for another 30 years.

 

[drew]

Bummer if the switch cannot be removed.

is there a way to spray in contact cleaner? Maybe drill a small hole and then seal it up aftwards?

I don't know enough about contacts, should some sort of lubricant be injected after cleaning?

 

[Old Guy]

If you want to go drilling holes and spraying things in, I suggest something like Caig's Deoxit. Probably the D series.

https://caig.com/deoxit-d-series/

Available in spray cans with straws. Caig claims it removes contact oxidation and protects the contact. Dirt should not be much of an issue in what looks to be a sealed micro switch like device. I know a lot of people who place great faith in the Caig products. I find their website just a little too snake-oil like. I have used MG Chemicals contact cleaner. Primarily a plastic safe de greaser. It doesn't really improve contact operation other than eliminating the physical dirt factor.

Personally, I would be inclined to clean and lubricate the switch actuator; but, leave the contacts alone.