2006+ Honda Civic Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
64 Posts
Discussion Starter #1
looking through the posts on footwell lights has anybody done a dimmer on a diy job?

if a blue led in the honda holes needs a 510ohm resistor for ~20mA, would a 1kohm pot in series be a good dimmer?

I was thinking you could put a mini pot in one of the cutouts for the heated seats (I'm getting a 3 door) with a little black knob and wire to the back of the cig lighter with in line fuse. leave permanently connected and just turn up and down as personal preference?

When 'off' at 1.5Kohm the current would only be ~7mA which would be virtually no light or not very noticeable light? or just use a pot with a switch to isolate?

Any ideas if linear or log would be the way to go, or if a 4.7kohm pot (for even lower 'off' current' would just have too small an adjustment range to be worthwhile? Or would a 4.7k pot with a parallel 4.7k resistor to take it down to 2.3k or something be better?

It's just I was thinking that an adjustment would be a very cheap way of "simulating" the honda 2 tone arrangement, and maybe slightly better if you could tweak the amount of light to your preference for not being distracting for different circumstances.
 

·
Registered
Joined
·
11 Posts
Im not sure on the best values for the 'pot', but remember to keep the 510ohm resistor in series so that the max led current is not exceeded.
 

·
Registered
Joined
·
64 Posts
Discussion Starter #3 (Edited)
Hi, I thought that was obvious from the mention of a total resistance of 1.5k with a 1k pot. But looking at Maplin they have a 5 blue led strip working at 20mA which has the resistance built in designed to work on 12V:
Maplin > DC 12 V Blue LED Strip
so with this all you would need is a pot?
Just a question of whether a 1k pot would give a low light at max resistance, or a 4.7k pot (which should give a low light or "off" level) would give a decent adjustment range across the turn?

Need to glue the strips to the bottom of the plastic footwell panels I guess, tuck the wires up either side of the gearstick centre console at carpet level, need only take off the cig lighter/drinks holder part of the console to wire up?
 

·
Foglight Covers FORSALE
Joined
·
3,178 Posts
ive got a dimmer on mine, think it was a 10k, but does the job.
 

·
Registered
Joined
·
64 Posts
Discussion Starter #5
thanks for the reply, that's interesting. I asked the question because too high a pot value might have a small adjustment range and turn into a kind of off/on rotate?
 

·
Foglight Covers FORSALE
Joined
·
3,178 Posts
yes this is also correct, go for 5k as i have a very small amount of movment but it does the job and once you get a brightness you like you wont move it from that setting. i can turn mine off as well.
 

·
Registered
Joined
·
24 Posts
Hi all,

It is possible to connect the LED strips from Maplins to the interior light circuit so that they automatically light up and fade out with the doors, locks and ignition in exactly the same way as the lights do. I have done this recently and so far it is working well. Will attempt to post some pics if anyone is interested.
 

·
Registered
Joined
·
64 Posts
Discussion Starter #8
Hi, yes, that is a brilliant solution, but I'm just a coward about running wires down from the roof :)
 

·
Foglight Covers FORSALE
Joined
·
3,178 Posts
yes that is how mine are done. i wired to the blue led in the roof console, work a treat:D
 

·
Registered
Joined
·
24 Posts
You don't need to run the wires from the light itself. I removed the front light to determine which wires control the dimming effect. I then removed the lower dash panel, under the steering column, to loacte the same wires behind the fuse box. The wires you need are the light blue/silver banded (constant 12v) and the light green/silver banded dimmed/controlled ground. The two wires can be tapped into with scotch locks below the blue connector that these wires run into.
I can also switch the lights on permanently.

I will take some more pictures of the finished install as the ones I have are too big to upload.
 

Attachments

·
Registered
Joined
·
64 Posts
Discussion Starter #11 (Edited)
that's very good information, thanks. I see how the footwell leds will follow the roof lights, but for constant on you need another 12V line, presumably with an over-ride switch somewhere?
From the cig lighter or another 12V in the back of the fusebox?

Maplin have a centre off 2 position rocker switch and I was thinking of putting it in the space for the heated front seat switch cutout, with one position full and the other dimmer. This could be fed either from an ignition 12V from the cig lighter, or plumbed into the roof lights as you helpfully describe.

With 2 high brightness 5mm blue leds in series, 270ohms would be full and something like 560/680ohms dim? Might be more reliable than a pot unless you get a wirewound.

I can see a suitable hole for a rubber grommet/led in both panels. The driver side hole is easy to get to without unscrewing anything. The passenger side is more difficult to get to the back of the hole at first glance.
 

·
Registered
Joined
·
24 Posts
Because the fade effect is achieved by a controlled ground you need a seperate constant ground connection via an on-off-on switch available from Maplins. I mounted my switch under the dash with velcro tabs. The box, again Maplins, contains my inline fuse holder and connection block.
The LEDs were attached to plastic strips to support them and these attached with velcro to the underside of the dashboard. The entire install can be easily disconnected and reused.

I will draw a circuit diagram soon and post it on here.
 

Attachments

·
Registered
Joined
·
64 Posts
Discussion Starter #14
so for constant "on" you just switch the dimmer ground to a normal ground?

and you could either have a pot for dimming in series or have a 2 position switch with a 20mA position for full brightness and say a 5mA position for less intrusive brightness while driving...

I suppose it all depends on whether you choose an led strip already configured for 12V or a single high brightness led each side in series with your choice of resistor/pot.
 

·
Registered
Joined
·
61 Posts
Because the fade effect is achieved by a controlled ground you need a seperate constant ground connection via an on-off-on switch available from Maplins. I mounted my switch under the dash with velcro tabs. The box, again Maplins, contains my inline fuse holder and connection block.
The LEDs were attached to plastic strips to support them and these attached with velcro to the underside of the dashboard. The entire install can be easily disconnected and reused.

I will draw a circuit diagram soon and post it on here.
Can you post a diagram, of what is needed for applying the switch?
I don't understand the on/off part :(

Thanks
 

·
Registered
Joined
·
10 Posts
Crackin', I'm very interested in having a go.

How does this circuit work..? Does the 'controlled ground' drop from 12 volts to extablish a potential difference between it and the constant 12V allowing current to flow from the 12V to the 'controlled ground' through the LEDs..?

I'd appreciate a circuit diagram if you can.
 

·
Registered
Joined
·
24 Posts
Thats basically it. I will try to find time to draw a diagram but its really quite simple.
Positive 12v to your choice of lighting via an inline fuse, connection to centre terminal of an on/off/on type switch. One terminal straight to earth and the final third terminal connects to the dimmed earth.
 

·
Registered
Joined
·
10 Posts
Cheers Bananas.

I'll get my head under the dash and see if I can identify the wires. If after that I'm feeling confident, I might give it a go.
 

·
Premium Member
Joined
·
738 Posts
You don't need to run the wires from the light itself. I removed the front light to determine which wires control the dimming effect. I then removed the lower dash panel, under the steering column, to loacte the same wires behind the fuse box. The wires you need are the light blue/silver banded (constant 12v) and the light green/silver banded dimmed/controlled ground. The two wires can be tapped into with scotch locks below the blue connector that these wires run into.
I can also switch the lights on permanently.

I will take some more pictures of the finished install as the ones I have are too big to upload.
I had a look, yesterday, for the blue & green wires behind the fusebox, but couldn't find them. My 2007 Type S GT doesn't have a blue plug in the location shown the photos - I have two white/grey plugs. Needless to say, the wire colours are different as well :(

Anyone any ideas where else they might be ? - I don't want to connect to the glovebox lights, as I want my footwell lights to dim with the overhead lights.
 

·
Registered
Joined
·
24 Posts
PJR you need to remove the bottom section of dash from under the steering wheel, you won't be able to find the plug in my pictures unless you do this.
 
1 - 20 of 21 Posts
Top