Where can I tap into the headlight wire?

[masphx]

I'm installing a gauge and would like to know where I can tap into the headlight wire so that when my headlights are turned on the gauge dims. Looking for some place in the steering color/ dash. Thanks.

 

[Brilliant]

tap any backlit switch light

 

[TheDurk]

Do I understand that you have a digital gauge which has a specific "DIM" wire that reduces its brightness when a 12V+ signal is applied? If so, be careful with a headlight tap, as 1998's are non-DRL and the headlights are ground-switched. Short version, you can't use the headlight circuit without a relay if the is DIM toggle is how I imagine. I would suggest tapping the taillight circuit which is hot-switched.

The factory digital clock has a DIM circuit all ready for you to use and easy to find. It is a solid green wire on Pin 3 of the clock plug. It is a direct tap off the Taillight circuit. (I used my '99 EWD but I am 90% sure the '98 is wired the same. If not, it will not be hard to figure which of the four clock wires come on with the tails. The others are a ground (black/white), full-time power (blue-yellow), and key on power(gray)).

You wouldn't want to tap a dimmable gauge or switch light for this as the voltage may not trigger the DIM function on your gauge if the rheostat is turned down low. Another place would be the feed to the dash rheostat. That is also a solid green wire. In fact, almost any solid green wire behind the dash should be part of the same taillight circuit. Dimmable feeds will be white with a green stripe so avoid those. This part definitely applies to 1998.

 

[masphx]

Do I understand that you have a digital gauge which has a specific "DIM" wire that reduces its brightness when a 12V+ signal is applied? If so, be careful with a headlight tap, as 1998's are non-DRL and the headlights are ground-switched. Short version, you can't use the headlight circuit without a relay if the is DIM toggle is how I imagine. I would suggest tapping the taillight circuit which is hot-switched.

The factory digital clock has a DIM circuit all ready for you to use and easy to find. It is a solid green wire on Pin 3 of the clock plug. It is a direct tap off the Taillight circuit. (I used my '99 EWD but I am 90% sure the '98 is wired the same. If not, it will not be hard to figure which of the four clock wires come on with the tails. The others are a ground (black/white), full-time power (blue-yellow), and key on power(gray)).

You wouldn't want to tap a dimmable gauge or switch light for this as the voltage may not trigger the DIM function on your gauge if the rheostat is turned down low. Another place would be the feed to the dash rheostat. That is also a solid green wire. In fact, almost any solid green wire behind the dash should be part of the same taillight circuit. Dimmable feeds will be white with a green stripe so avoid those. This part definitely applies to 1998.

Cool, I'm tapping for an innovate mtx-l afr gauge. Directions said to tap the headlights and for some reason not a 'dim' wire.

 

[TheDurk]

Cool, I'm tapping for an innovate mtx-l afr gauge. Directions said to tap the headlights and for some reason not a 'dim' wire.

I looked up the manual. They are saying the same thing I am, you want to avoid anything downstream of a rheostat. Find a solid green wire and you'll be fine.

Connect the WHITE wire to a headlight power wire (a wire that supplies current to the headlights). This enables the display to dim for better
nighttime viewing. DO NOT CONNECT THIS WIRE TO THE
HEADLIGHT DIMMING WIRE. Connection to this rheostat type of
switch will cause the gauge to malfunction. If you chose not to utilize the
dimming feature, connect the WHITE wire to ground.

 

[masphx]

I looked up the manual. They are saying the same thing I am, you want to avoid anything downstream of a rheostat. Find a solid green wire and you'll be fine.

Cool, will do that. Thanks for your help :cheers:

 

[johnbradshow]

Hi, does any one know if I replace the factory headlights with aftermarket ones?

Will the factory light switch work with high and low beams with these projector headlights? And how do I connect the halo DRL to the vehicle?

Thanks for helping...

 

[IBallEngineer]

Hi, does any one know if I replace the factory headlights with aftermarket ones?

Will the factory light switch work with high and low beams with these projector headlights? And how do I connect the halo DRL to the vehicle?

Thanks for helping...

Lots of different systems out there, can you scan the wiring diagram for the aftermarket lights you have? Most do allow lo/hi operation, but some don't.

:hungry: