DIY - Headlights off with the Ignition Switch

[CTScott]

Originally Posted by Setheroo

Is there a reason to keep the buzzer hooked up? Is it the same buzzer for leaving the key in the ignition?

The buzzer is easily removable from the instrument cluster circuit board. The one buzzer is used for warning for seat belts, headlights, and key in ignition.

[townkat]

hi all,
i was just wondering, aren't the headlights already powered through a relay from factory? (or all the power go directly trough headlight switch ?)
if so can't we make the change directly there? without adding another relay? just by changing the command source?

btw i have an yaris d4d, automatic transmission, with keyless entry and start and digital dash and i love it

[CTScott]

Originally Posted by townkat

hi all,
i was just wondering, aren't the headlights already powered trough a relay from factory? (or all the power go directly trough headlight switch ?)
if so can't we make the change directly there? without adding another relay? just by changing the command source?

btw i have an yaris d4d, automatic transmision, with keyless entry and start and digital dash and i love it

They are controlled by a set of relays, but those relays are controlled by the headlight stalk. If you wanted to make the ignition control the headlights instead, then you could move the control point, but if you want the ignition to intercept that feed, as I did here, you need another relay.

[townkat]

so, headlight stalk control some relay, so there is little current going trough it

Originally Posted by CTScott

You really want a relay in there to keep the headlight and ignition circuits separate. The relay allows one circuit to switch the other, without being a direct connection.

if you can detail a little bit on this i would love to understand more, what can happen bad if relay is not used, as i am very tempted to wire them directly if i can't see a direct drawback

thank you

[shepd]

If you put more current through a switch than it can handle, typical failure modes include it becoming unreliable, it completely failing, the item physically disintegrating (due to arcing), and at worst, fire.

If a switch is meant to control a relay (likely less than .2 amps) and you place a 10 A current through it (what your headlights draw) I would lean to the end of the list (disintegrating or fire).

[townkat]

i know that, but i understand that the headlights stalk just powers the command of some relays, so just few milliamperes ...

Originally Posted by CTScott

They are controlled by a set of relays, but those relays are controlled by the headlight stalk.

and my suggestion is to change the source of the headlights stalk switch, not its destination

anyway, thanks for the heads up, what you say it's true, just that i think it is not the case here..