Controlling 2 sets of lights with 3 switches

Headlights to tailights and everything in between.

Moderators: Helpinators, Moderators

Post Reply
voodoochylde
First Gear
Posts: 63
Joined: Sun Apr 23, 2006 2:55 pm

Controlling 2 sets of lights with 3 switches

Post by voodoochylde »

I've got a cheapo set of no-name fogs under the bumper relayed to my lowbeams and a set of optilux 1900's on a redneck/homemade lightbar relayed to my highs. Right now, both are on their own SPST switch.

What I'm curious of is whether I can use an SPDT switch to control these guys. First on-position has regular functionality, center position is off obviously, while the second on-position would (in my "vision") make both sets of lamps come on simultaneously.

HOW?! I'm semi-electrically-inclined but I'm not an electrician by far. I've got a meter and enough patience to just sit and play with it for a few days at a time but help would be great.

Thanks in advance.
Legacy777
Site Admin
Site Admin
Posts: 27884
Joined: Tue Oct 15, 2002 11:37 am
Location: Houston, Tx
Contact:

Post by Legacy777 »

Just some clarification, are you looking to turn both sets of lights on with a single switch? Or are you looking to do something more complicated?
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
magicmike
Fifth Gear
Posts: 2772
Joined: Thu Nov 21, 2002 8:30 pm
Location: USA, RI

Post by magicmike »

I have something in mind but ned to draw it up somehow and post an image. you need to wire both sets through a relay and have the triggers of both relays going to the switch. one trigger from each relay on each pole of the switch. then you just need to connect a diode between the two trigger wires, aimed in the direction for which set you only want to trigger alone. its important to trigger the relays with a ground and use the ground at the SPDT stitch. play with the diode for correct lighting it it will work. I'll try to draw something up and post it when I have time.
-Mike

2011 Infiniti G37x Sedan - Current
2007 Ducati 800ss - Current
1994 Subaru Legacy Sport Wagon (White)
1994 Subaru Legacy Sport Wagon (Silver)
2003 Infiniri G35
1998 Infiniti I30t
1995 Honda Civic DX
1987 Subaru GL Wagon
1987 Subaru Loyale
mikec
Third Gear
Posts: 893
Joined: Tue Jan 21, 2003 8:27 pm
Location: Toronto, Ontario
Contact:

Post by mikec »

Why not just connect whichever set you want on whenever the switch is on to both sides of the switch? Then connect the other set of lights to the Both position you've selected.

Obviously using relays to actually turn the lights on.

I don't see a need for any diodes.
"That shouldn't be a problem, since I do regularly visit the realm of subatmospheric manifold pressures." -- vrg3
magicmike
Fifth Gear
Posts: 2772
Joined: Thu Nov 21, 2002 8:30 pm
Location: USA, RI

Post by magicmike »

mikec wrote:Why not just connect whichever set you want on whenever the switch is on to both sides of the switch? Then connect the other set of lights to the Both position you've selected.

Obviously using relays to actually turn the lights on.

I don't see a need for any diodes.
well if you connect it like your saying when you only want to turn one set on it will be connected to the other side of the switch and it will turn both sets on. the switch needs to be switching the ground for the relays and the diode only lets the ground through in one direction so that both can come on in one way but the other way only one will come on but they are both connected at the same time. or just dont use a diode and use a DPDT switch instead. his choice.
-Mike

2011 Infiniti G37x Sedan - Current
2007 Ducati 800ss - Current
1994 Subaru Legacy Sport Wagon (White)
1994 Subaru Legacy Sport Wagon (Silver)
2003 Infiniri G35
1998 Infiniti I30t
1995 Honda Civic DX
1987 Subaru GL Wagon
1987 Subaru Loyale
mikec
Third Gear
Posts: 893
Joined: Tue Jan 21, 2003 8:27 pm
Location: Toronto, Ontario
Contact:

Post by mikec »

I was thinking SPDT with a centre off position. The centre terminal would ground whichever relay(s) were necessary.
"That shouldn't be a problem, since I do regularly visit the realm of subatmospheric manifold pressures." -- vrg3
voodoochylde
First Gear
Posts: 63
Joined: Sun Apr 23, 2006 2:55 pm

Post by voodoochylde »

magicmike wrote:I have something in mind but ned to draw it up somehow and post an image. you need to wire both sets through a relay and have the triggers of both relays going to the switch. one trigger from each relay on each pole of the switch. then you just need to connect a diode between the two trigger wires, aimed in the direction for which set you only want to trigger alone. its important to trigger the relays with a ground and use the ground at the SPDT stitch. play with the diode for correct lighting it it will work. I'll try to draw something up and post it when I have time.
This is kinda what I was thinking ('cept I hadn't thought of a diode). Just not sure how to do it...

To clarify my current setup. I've got a set of fogs triggered by my low-beams. These only work with my low-beams on and are activated by an SPST switch hooked to a relay which is triggered by my lows.

My driving lights are exactly the same except the relay they're on is triggered by my high-beams.

I currently don't have anything setup to turn either set on at will, they're both dependent of their respective beam selection.
magicmike
Fifth Gear
Posts: 2772
Joined: Thu Nov 21, 2002 8:30 pm
Location: USA, RI

Post by magicmike »

um I'm confused. why do you want the fogs on all the time and the driving lights only on with your highbeams? normally you have the fogs on a switch so you can turn those on when its um foggy and the driving light should be able to come on with your parking lights and not dependant on your headlights. All lights should shut off when the highbeams are triggered.
-Mike

2011 Infiniti G37x Sedan - Current
2007 Ducati 800ss - Current
1994 Subaru Legacy Sport Wagon (White)
1994 Subaru Legacy Sport Wagon (Silver)
2003 Infiniri G35
1998 Infiniti I30t
1995 Honda Civic DX
1987 Subaru GL Wagon
1987 Subaru Loyale
Post Reply