CHMSL Retrofit

[opus10583]

Hi,

I've had a go at this in the General area, but maybe I can develop some traction here...

Living hear in the land of Lumbering Living Rooms, I think a CHMSL might be a great idea for my Spider.

Does anyone know of a pre-packaged wiring kit for a third brake light? Does anyone know of am existing wiring schematic for a third brake light?

...Anyone have any guidance for a car electrics neophyte?

I'm already acquiring bits for a red rear fog light, just because, and what I'd ultimately like to do is make it a Left Low Mounted Stop Light that can be switched full on for fog/rain or rural roads: Anyone have any thoughts about that?

Anyone have a fog light switch solution they'd care to share or brag on?

Thanks,
Mark

[maytag]

you are jumping to a conclusion that the CHMSL actually works.

NHTSA seems to have backed waaaay off of their original claims on it. Last I knew, there were publishing a rather "iffy" statistic of something less than a 5% reduction in the likelihood of being rear-ended.
So to me... I don't see it being a good mod. But that's just me.

a switch and relay is easily set-up, and if you check ebay or google "custom tail=lights" there are lots and lots of options that could be mounted to the trunk-lid. But I'm cringing as I say it.

[opus10583]

you are jumping to a conclusion that the CHMSL actually works.

NHTSA seems to have backed waaaay off of their original claims on it. Last I knew, there were publishing a rather "iffy" statistic of something less than a 5% reduction in the likelihood of being rear-ended.
So to me... I don't see it being a good mod. But that's just me.

a switch and relay is easily set-up, and if you check ebay or google "custom tail=lights" there are lots and lots of options that could be mounted to the trunk-lid. But I'm cringing as I say it.

Haven't seen the 5% analysis, conclusions based on public information...

Never considered an actual CHMSL, I'm mounting a red rear fog/rain light anyway, period style Hella, thought I might make it pay its way.

Love your sig, btw.

Thanks,
Mark

[maytag]

I get it. I thought you were considering BOTH the CHMSL and a rear-low-mounted fog light.

I agree with you that the rear fog-light is not just period-correct, but very European, and would be at home on our cars. I still think it'd look like an after-thought on mine, but if yours is such that it is all period-correct, then go for it!

If it were me, I would mount a switch way up under the dash where it wouldn't be seen but was easy to reach from the drivers' seated position. Wire it up with a relay. Pretty straightforward.

[opus10583]

I get it. I thought you were considering BOTH the CHMSL and a rear-low-mounted fog light.

I agree with you that the rear fog-light is not just period-correct, but very European, and would be at home on our cars. I still think it'd look like an after-thought on mine, but if yours is such that it is all period-correct, then go for it!

If it were me, I would mount a switch way up under the dash where it wouldn't be seen but was easy to reach from the drivers' seated position. Wire it up with a relay. Pretty straightforward.

Don't get me wrong, I'm not a complete anorak, I just think the period correct RRFL fits in better than a modern LED piece. And where I'm going fog is a real concern.

Thought about something similar for the switch, seems a standard Spider headlight switch would do it, positioned outboard alongside...

Thanks,
Mark

[seabeelt]

Post som pics when you geterdone.
r

[opus10583]

Hi,

I finally got this wired up: Hella HL95217 light from Susquehanna, DPDT and Quick Disconnect Adapters from Radio Shack.

Does exactly what I want.

Took me two afternoons, because THE BRAKE LIGHTS SWITCH HOT SIDE ON MY CS1 IS SWITCHED ON THE IGNITION SWITCH!!!

I spent an afternoon trying to troubleshoot stupidity...

And, seriously: WTF??!!!

Ciao,
Mark

Pics in a week, it was too damned cold and too damned ridiculous.

[geert]

hallo,

if visibility in fog/heavy rain is your concern, why not wire the rear fog light as a real fog light, and not as an extra stop light ? ( as we do in Europe)
so your Fiat is more visible in fog all the time, not just when breaking.

Easy fit with extra fuse, extra switch+ light under the dash . To prevent leaving the fog light on best wired to get power only when the lights are on ( with a relais).

if you want more details/pics, give a sign.

groeten, Geert.

[opus10583]

Hi Geert,

Thanks!

It is wired to function as a third brake light when among the pinheads in their four-wheeled duplex media centers, or as a full-on rear fog light for comin' down the foggy mountains or riding the lonesome stretch of highway; there will be no heavy rain*.

It can also be switched fully off should it blow the brake lights fuse.

Ciao,
Mark

*Been there, done that, outgrew the t-shirt long ago: 8-hours driving a 124 Spider in a relentless blizzard from Boston to NY (~450km).

hallo,

if visibility in fog/heavy rain is your concern, why not wire the rear fog light as a real fog light, and not as an extra stop light ? ( as we do in Europe)
so your Fiat is more visible in fog all the time, not just when breaking.

Easy fit with extra fuse, extra switch+ light under the dash . To prevent leaving the fog light on best wired to get power only when the lights are on ( with a relais).

if you want more details/pics, give a sign.

groeten, Geert.

[geert]

It can also be switched fully off should it blow the brake lights fuse.

Ciao,
Mark

*Been there, done that, outgrew the t-shirt long ago: 8-hours driving a 124 Spider in a relentless blizzard from Boston to NY (~450km).

good idea ! , but when it happens in that fog ...
or you could use a "off"-relais in parallel with the break light function (to switch the fog light off when braking)
( or homemade 2 bulbs in the same 'fog'-light )

groeten, Geert.

[Tobi]

I am not sure if I got the problem right but if it is about separating the power going into the light bulb a couple of blocking diodes should do the trick. They would turn your wires into a one way wire.

[opus10583]

Hi Geert,

Using these(http://www.radioshack.com/product/index ... Id=2103503, two of the top one pictured) I pick-up the hot side of the brake switch and the switched side of the brake switch and feed both into the dpdt switch with the common pole feeding the light: The brakes fuse fuses the third light either way.

Thanks,
Mark


P1050826 by opus10583, on Flickr

It can also be switched fully off should it blow the brake lights fuse.

good idea ! , but when it happens in that fog ...
or you could use a "off"-relais in parallel with the break light function (to switch the fog light off when braking)
( or homemade 2 bulbs in the same 'fog'-light )

groeten, Geert.