led wiring

Printed From: the12volt.com
Forum Name: Lights, Neon, LEDs, HIDs
Forum Discription: Under Car Lighting, Strobe Lights, Fog Lights, Headlights, HIDs, DRL, Tail Lights, Brake Lights, Dashboard Lights, WigWag, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=137362
Printed Date: April 28, 2024 at 4:33 PM

Topic: led wiring

Posted By: cam english
Subject: led wiring
Date Posted: October 02, 2014 at 12:05 AM

I want to wire some LEDs to a 3 way toggle switch where one position is off one is solid on and one is wired to an amp so it with flash to the bass. This is probably a stupid question but how would I go about doing this? Will any 3 position switch work? And what's the best way to wire the LEDs to stay solid on?

Amy help would be great

Replies:

Posted By: oldspark
Date Posted: October 02, 2014 at 2:08 AM

On, off & amp - a single pole 3 position switch (SP3T) usually centre off.

Common to the LEDs suited to automotive (up to say 15V) or whatever supply you have.
One side to the supply +V.
Other side to the amp where unless above ~300W it should not blow 12V-15V LEDs.

Posted By: cam english
Date Posted: October 02, 2014 at 9:40 AM

Can you please post a pic of what the switch looks like and explain this to me a little more because I can't understand how to wire it and thanks for the help

Posted By: oldspark
Date Posted: October 02, 2014 at 6:02 PM

I cant draw a diagram, but the switch could look like this:

posted_image

They are usually described as a 3 position SPDT ON-OFF-ON or Single Pole ON/OFF/ON.
You can get larger versions, some with spade terminals to avoid the need to solder.

The centre terminal goes to the +ve end of your LEDs whose other end goes to ground. BUT that assumes one side of your speaker or amp output is grounded, if it isn't you need different wiring and a DPDT or Double Pole ON/OFF/ON equivalent like:

posted_image

(Thanks to guitarelectronics.com for the above images.)

One end terminal goes to one source (+12V etc) and the other to the other source (speaker or amp etc).

If the sources do not share the same grounds or -ve side then you also need to switch the GND sides.
That's done by using the 2nd Pole (set of 3 contacts) in the Double Pole ON/OFF/ON.
Each GND is connected to terminal next to its +ve connection, eg LED+ is from the centre (say) right terminal and LED- from the left centre terminal. The +12V input will be +12V to RHS (say) top terminal and GND to LHS top terminal. Likewise amp or speaker GND to RHS lower terminal.

The DPDT version is the safest. It keeps both the +ve & -ve from each source isolated from each other. (IE - use a DPDT if in doubt about what GND the amp output or speaker uses.)