TDM850-900 (1991-2002) : Headlight & pilot lights

In France and in many other countries, every two-wheels engine vehicle is required to have the headlights on during daylight riding. Less known is that the position lights does not follow the same rule.

Actually daylight position lights are not required unless the average daylight level is poor : weather / season / latitude.

A bit of theory

The position lights on the TDM are made of :
• front light : 5W bulb.
• rear light : 5W bulb (TDM900), 5W x 2 bulbs(TDM850).
• dashboard : 5W (approx).
The total power consumption is 15W or 20W depending on the model. This is around 20% of total power consumption.

The main advantage when inhibiting the position lights is a longer battery lifetime : lower power consumption means lower battery duty.

I'm riding my 9er since 2002 with that mod, no trouble with the police.

From 1991 until 2002 the light switch is found on the right-hand switch casing. It is impossible to switch on the headlight without the position light going on too.

From 2003 on the position lights are always switched on (when the main switch is on). The mod is less easy to do, I'll publish it latter.

(image)1 - Engine kill switch
2 - Light switch
3 - Engine start switch

The light switch is a three wires switch : one input for the +12V (Red/Yellow wire) and two outputs for the position light (Blue wire) & the headlight (Blue/black wire).

There are three possible mods.

Tools & parts you'll need

• A screwdriver.
• A soldering iron.
• A hot glue gun.
Mods A & B only :
• About 20cm of wiring, same gauge or bigger than the original wiring.
• An additional switch (from an old computer power-supply - or a new one). Min current must be 10A.


How to

Start of the surgery :
• Open the right-hand switch casing : two screws.
• Remove the light switch from the switch casing.


Mod A

(image)What we want : Switch on the headlight separately.
A new switch is wired in parallel.
The headlights will be switched on when the original switch or the additional switch are switched on.
Daylight ride : the original light switch is off, the additional switch is switched on so the headlight is on. When riding inside a tunnel the original light switch will be switched on.
Night ride : only the original light switch is in use.

How-to :
• Solder a 10cm long wire on the Red/Yellow wire on the light-switch, don't remove the Red/Yellow wire.
• Solder a 10cm long wire on the Blue/black wire on the light-switch, don't remove the Blue/black wire.
• Lead the two wires outside the switch case, then solder them on the additional switch.
• Put hot glue around the additional switch soldering as protection against moisture.
• Glue switch under the switch casing with cyanocrylate glue : either remove the plastic surrounding from one side of the switch, or (better) make a notch on the original switch casing with a file. Both surfaces must be flat & clean in order to ensure a reliable gluing.
• Replace main light switch inside casing, close casing.


Mod B

(image)What we want : Switch off the position lights separately.
A new switch is wired in serial.
The position lights will be on when the original light switch and the additional switch are both on.
Daylight ride : the original light switch works as usual, the position lights are switched off by using the additional switch. When riding inside a tunnel the additional switch will be switched on.
Night ride : the additional switch is permanently switched on.

How-to :
• Unsolder the Blue wire from the light-switch and solder in place a 10cm wire, same gauge.
• Lead the two wires outside the switch case, then solder them on the additional switch.
• Proceed with the additional switch as described above.

Mod C

(image)What we want : Modify the main light light switch.
Headlight wiring and position light wiring are simply permuted.
No need for an additional switch, the main light switch works as follow :
• All off
• Headlight is on (daylight driving)
• Headlight and position light are on (night driving)
Minus point : the position lights can't be switched on independently.

Howto :
• Unsolder the Blue wire and the Blue/black wire from the light-switch.
• Solder the Blue wire in place of the Blue/black wire.
• Solder the Blue/black wire in place of the Blue wire.
• Replace main light switch inside casing, close casing.

Always check your local driving regulations.
This page is based on the French driving regulations.


Please enter your account details

Lost account details×

Enter your e-mail to receive your account details



Why sign-up ?

  • It's free but you can make a donation.
  • You gain access to fonctionalities otherwise not available.
  • It will boost your sex-appeal and allow you to time-travel.

How to sign-up ?

Username Required - 3 to 20 letters or digits
Password Required - 6 to 20 letters or digits
E-mail Required - enter a valid E-mail address

My account×

Modify my password

Current password

New password
Confirm new password

Modify my E-mail

Current E-mail

New E-mail
Confirm new E-mail

Delete my account

Current password

Add messageEdit message×
  • Your comments, feedback and suggestions are welcome !
  • Please use forums for any questions requiring a quick answer.
  • Your questions should relate to the TDM / XTZ / TRX only.
  • No links, ads, sales, doc requests. Thanx.
  • Edit your message then click the 'Ok' button.
  • An empty message will be deleted.
Name Required - 3 to 20 letters or digits
E-mail Optional - will be encrypted
Country Optional


Terms of Service and Privacy Policy×

Collection & use of your personal information

When registering to the site, you will be asked personnal informations such as your e-mail address, your country of origin, etc. This site will not provide or sell your personal information to a third party without your consent.

The site may collect information about your visit in order to operate and improve the site and the service it delivers. This includes the pages you view, the links you click and other actions taken in connection with the site. It also collect certain standard information that your browser sends to every website you visit, such as your IP address, browser type and language, access times and referring Web site addresses. Theses data is collected only for statistical usage and will not be used for any other purpose. This data is periodicaly erased (max 3 months).

Use of cookies

This site uses cookies to memorize your display language option and your session data. No personnal information is stored into the cookies. If your browser does not accept cookies, you will not be able to change language or open session.

Use of e-mail address

This site will not sell, lease or rent the e-mail you provide while registering or posting messages. E-mail addresses will not be used for any purpose other than sending you service e-mails : registering confirmation, updating your data or requiring a new password.


This site does not allow any messages containing :

  • Spam : repeated (commercial) messages.
  • Referral Programmes or Pyramid Schemes (links to websites through which you have a personal gain).
  • Rude and disrespectful behaviour, whether it is to members of this site or the staff of this site.
  • Language that is obscene, vulgar, sexually orientated, hateful, threatening or violate any laws.
  • Offerings of products (tangible or intangible) and services that you do not have legal disposition over.

This site reserves the right to edit or delete reactions and to ban any user violating the rules without notice. Freedom of speech is a right, however this does not mean we are obliged to publish your opinion.

This policy is subject to change without prior notice.




Send SMS×
Name Required - 3 to 20 letters or digits