hooking into high beam relay

[bad_religion_au]

on a 76 40 series (assume similar for other years) where do you guys hook into the high beam circuit, so the drive lights auto dip, and do you wire it through two relays (drive light packet says that toyota and nissan headlights require a certified auto elec) something about negative earth, or earthed switch or something..

any help appreciated

[Macca177]

do u mean u want to hook more lights up to swictch on when the highbeam is turned on ... if so u just splice the line thats high beam on the back of the light and run it to the realy to switch the realy on and off?

[bad_religion_au]

no, legally you have to have a relay that turns your drive lights off if you switch your high beams off, therefore i need to hook into the low voltage high beam circuit... wondering where people do this.

[Mick_n_Sal]

I did it as follows.
I spliced into the High beam +ve at the back of the headlight, fed from here to my spotlight switch, from there, through the relay coil to ground.

When hi-beam is on, power flows through spotlight switch on dash to activate hi-beam relay. If you dip your lights it pulls the Volts from the spotlight switch and de-energises the relay.

Hope this makes sense.

Mick_n_Sal

[bad_religion_au]

that's exactly what i wanted... this puts the switch and the headlights in series, right, so voltage drop is minimal at the normal high beams?


is there a prob with taking that many amps through the firewall and through a switch? or is it roses

[Macca177]

i have the same setup and i ve never had a problem with the wires comeing threw the firewall.

[Mick_n_Sal]

Although you have taken a feed off the back of the hi-beam and through to the spotlight switch, there is minimal current on this wire. You are only using this to fire the COIL of the relay .5 of an amp max. The high current side of the relay will all be in the engine bay where you are keeping voltage drop to a minimum by using decent size cable say 4sq mm. and ensuring that this circuit is fuse protected.

If you are still having trouble with this, PM me and I'll email you a circuit diagram.

Mick_n_Sal

[bad_religion_au]

nah, i got it covered. thanks for your help... just a slight concern when i read "high beam cable" and :back through the firewall". anyway, gotta wait for some time to hook it up now. thanks