I experienced the annoying problem that the small plastic bumper which is supposed to push the switch when you depress the clutch deteriorates and breaks. Then you can't start your S2000!
Try as I might I couldn't reach up there to put a new one in, so I decided to do a bypass, which solved this problem. Here's my solution for access to the connector - remove the 2 10mm screws which hold your cabin under-dash fuse box, unplug the main bus connector and move the box out of the way. You can now access the yellow connector to your clutch ignition lock switch and unplug it.
Next, bridge the board-side male plug with a small wire. You might want to wrap it in electrical tape to prevent it from working loose.
That's it.
I'm posting this because i was unable to find a good description of how to do this on these forums. Hope it saves you some time!

Viewing the connector

Bridge the male connector which is attached to the fuse box.

 

There has to be a dozen or more threads on bypassing clutch interlock. From paper clip to elaborate relay based configs.

All of them are easier than what you did. Not sure how you searched. But the threads are out there.

Here is the one I did:

clutch interlock byoass using brake pedal


another method

 

Sure, I'm just sharing my experience is all..
I wasn't looking to bypass it, I was trying to install a new plug to fix it!
The bypass was my last resort. I've seen a few threads which talked about bridging the plug but they didn't describe how to do it.

 

To actually replace the plug, people have reported need to remove pedal assembly from car. Not exactly friendly procedure.

 

Did you know not all have the 16 pin OBD ?
Some of the older ones use the 3 pin plug.

Remember I’m in UK.

 

Is there a quickie temporary solution for this? Our cars are getting old and those nylon spacers won't last forever. What I'd be looking for is someway to crawl under the dashboard and stuff something in there to get the car started awaiting a proper repair. Planning a couple overnight trips with the car this summer and don't want to have to park on a hill every night. (Not interested in permanently disabling the interlock.)

If I get "unlazy" and the temperature cools down I'll probably just proactively fit new spacers since these are standard Honda parts.

-- Chuck

 

There are 2 means of bypass that do not disable the clutch interlock. They merely override it. Really they create a secondary means of interlock.

One is to wire the interlock to another momentary switch, aka a push button switch. Either a switch you'd add somewhere, or an existing switch you'd dual purpose.

Basically, its tap into the two wires of the clutch bypass, and also route each wire to the 2 wires of the other switch.

Then you can use clutch as you always have, but if the stopper ever falls out and car won't start, you can then use the secondary bypass switch to be able to start car.

The second method is really just a variation on the first. Using the brake pedal switch as the secondary override. The only reason this differs from first method is the brake switch is normally closed (its always on until you press brake, then its off). So wiring this up requires a simple relay.

With either method, if you always use the secondary interlock instead of pressing clutch, you're saving wear on crank bearing, the thrust washer bearing. Its especially susceptible to cold start dry wear, moreso than other crank bearings. So you'd be preserving engine life (or at least preventing a not uncommon way these engines have died).

The brake override method is a bit easier, and safer, to use as the new way to start car. Mimics all modern cars, and prevents car from taking off in gear if accidentally forgot to put in neutral.

But even if you decide to keep using clutch, it'd be an easy secondary means to start if primary ever fails on a trip.

Here is diy thread:
brake pedal interlock override

 

Wish I had the wherewithal to unbolt the fuse box and move the connector when I did my bypass....Instead my dumb ass did it the hard way of reaching up there blind and unplugging it after great struggle and removing the entire top layer of skin from my forearm.




My sweet bypassed clutch switch connector, with my own innovative retaining device!

 

Any instructions on how to remove the clutch pedal assembly? Unless absolutely necessary I am not a 'work around' type. I have new extra plastic tabs from replacing the easy ones clutch and brake. I understand they break, but in 20 years I'll be gone, so a one time fix is good for me.
Robert

 

Simple. Remove the retaining clip and clevis pin from the CMC to the pedal, undo the 2 nuts holding the cmc/pedal assembly to the firewall, unclip both connectors (safety switch / cruise control switch) and the pedal should be free. 10 minute job assuming you don't have a claustrophobic stroke and die in the process, lmao.