Ducati.ms - The Ultimate Ducati Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1
Hi

I have purchased a new neutral switch for my ST2 (part no: 53940201A)

Mechanically it looks identical to the original, but electrically it is different. The original had two wires coming off, where the new one has only one wire which goes into a round connector with a single pin inside.

Can I use this switch by altering the wiring or have I just got the wrong one and need change it?

Any comments or help appreciated

Cheers
 

·
Registered
Joined
·
45 Posts
What year ST2 is this? My 2000 ST2 has a single red wire coming from the neutral switch with a single pin connector. From 2001 onward the part number for the neutral switch is different (53910211A).
 

·
Ducati Designs
Joined
·
1,124 Posts
The switch just grounds the output lead. Having the switch screwed to the engine case should be all the ground you need. You can verify which wire is the output (should be yellow green) with a multimeter. The other lead should go to ground or nowhere.

pg
DD
 

·
Registered
Joined
·
45 Posts
Makes sense but will he still be able to plug into the harness? He said the original had to two wires which would require a two pin AMP plug rather than the single pin plug, i.e. different shaped connectors.

If you still have the old switch you could cut/crimp/soldered the old AMP connector to the new switch. Just make sure you connect the output wire of the new switch to the correct output wire on the old connector.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #5 (Edited)
Pictures

Hi

Thanks for your speedy and helpful replies

Just in case it helps the cause please find attached a couple of pictures. One shows the new switch and connector (old switch in the background) and the other shows the connector internally.

The year is a 1999

The wiring connectors are bullet connectors and look to be OEM. The bullets are strapped to the frame and it looks like the leads on the original switch would have been longer than the new one.



Thanks again all

Mark
 

Attachments

·
Registered
Joined
·
45 Posts
Can we get a pic of the bullet connectors that are part of the harness?

The reason I ask is that there should be a black plastic connector similar to the new switch connector. It should have the words AMP molded into the plastic housing. If there is just regular bullet connectors then I suspect the original connector has been removed so that your old switch (the other part number I stated before could be fitted).

This is ok, but you will need to cut the AMP connector off the new switch and add the correct sized bullet connector to fit the existing bullet connector from the harness.

The threaded part of the new switch will ground to the engine casing when you fasten it down, so you will only need to connect the red wire to the positive wire of the harness. This should be a Yellow-Green wire. The other bullet connect is your ground and is black. You don't need to connect this since the switch is already grounded to the engine case.

I think what happened here is a prior owner used a 2001+ neutral switch on your bike and fitted it by removing the original AMP connector and added a ground wire. Hence the two wire switch that was on there.

Send pic of the harness wiring connectors just to make sure.
 

·
Registered
Joined
·
45 Posts
Those are not factory connectors, albeit decent weatherproof bullet connectors. You'll need to cut the connector off your new neutral switch, crimp on the correct size bullet connector, and connect it to the Green/Yellow wire.

I'm not sure what else to tell you as the factory connector has been removed.

If you're not comfortable hacking in the new switch yet, install it, put the bike in neutral, use a wire to jumper from the single pin connector to the bullet connector just to make sure it works. Then if everything is okay, cut/crimp to fit the new switch.
 

·
Registered
Joined
·
3,883 Posts
Those are the factory harness from 1998 and 1999. They use to use 2 wires. But Drxzy is correct. Just connect the green/yellow wire to the new switch. You won't need the black one.

If you'd like to verify ahead of time, jumper both of these wires on the harness together (like with a paper clip). Neutral lite should be on. Rempve jumper, Neut. lite is off.
Take just the green/yellow wire and get it to touch the frame or engine somewhere for a good ground. Lite should come on.
 

·
Registered
Joined
·
45 Posts
Learn something new everday. I guess same part numbers for the switch doesn't mean the harnesses are the same. Did Ducati upgrade the harness in 2000? I know they made some changes to the electrical that year.

Thanks for the correction Stick.
 

·
Ducati Designs
Joined
·
1,124 Posts
Ducati upgraded lots of things in 2000. Especially electrics and connectors. Maybe the best ST2 models came in 2000, before they started downgrading components.

pg
DD
 

·
Registered
Joined
·
3,883 Posts
Many small and big changes thru the years:

Neutral switches went from 2 wires to 1 wire

1997 (EU) + 1998 had 420W single phase (2wire) stators and unique RR
Note that all the rest of Ducati models had 350W stators at this time. ST's were "special"

1999 on-up had the 520W three phase stators, with present-day RR (all model DUCs went to 520W)

Oil pressure switch went to a 2-wire arrangement on later models.

Side-stand switch got introduced in 1999 or 2000

I'm sure there were more changes. Like the signal for the starter relay being commanded by the ECU on newer models (vs. being done by the starter button directly)


EDIT:
one thing that got "downgraded" in the harness was the AC connector that's between the stator and the RR. The 1998 ST2 had a beautiful weatherproof AMP connector on the 2 AC wires. Now there's a crappy, non-WP connector on the 3 yellow AC wires.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #13
Thanks for your help everyone, not only has it pointed me in the right direction but its made interesting reading. Also, I've learnt a lot!! lol

I'll post a message when I've done it to let you know how I got on

Thanks again
 
1 - 13 of 13 Posts
Top