Third Brake Light

[jeffdgale]

Hi I have a 74 Avanti and would like to have the added protection of a third brake light. I was thinking that a later model Avanti that had it as a mandatory item due to the law might fit. Anybody have any information, suggestions or experience with solving this? Thanks

[Gunslinger]

There are add-on third brake light kits you can get from JC Whitney, Summit Racing, Jegs, and some hot rod catalogs. The wiring is probably pretty simple but I've never tried it.

JMenaker has installed one in his Avanti I believe, but I don't know where he got it from. If he happens to see your question I'm sure he can answer it.

[jmenacker]

Bruce:

I swapped in the LED brake light kit from Bob Ziff for brighter lights but did not add a center high brake light. Rechromed housings combined with the LED kit made a huge difference in visibility -- day and night.

Agree that the stock lamps with pitted housings leaves something lacking in the protection of investment department.

Joe M

[wdaly]

Hi I have a 74 Avanti and would like to have the added protection of a third brake light. I was thinking that a later model Avanti that had it as a mandatory item due to the law might fit. Anybody have any information, suggestions or experience with solving this? Thanks

My '88 had this light on the inside with a "pedestal-type" mount, the kind auto manufactures used at first, before they incorporated this light into the design of the car. Quite a convoluted device. I changed the incandesant light in it to an LED (I had the rear window tinted and wanted more/different light). Just this past year I finally removed the interior set-up and swithced to an exterior light that has 2 incandescant bulbs.

Here's the deal. These lights are hard to come by anymore because all cars for the past 20+ years have had them installed - so who needs replacements? When I say hard to come by I really mean your choices are quite limited. Checker, Advance auto, Whitney et. all do have selections (do it by internet). Trouble is they don't always distinguish between inside/outside capabilities.

Make sure the light aims "straight-out" not down or up / this can be difficult if trying to mount inside the Avanti extreme-swept-angle rear window. If you do mount inside the light should pretty much 'enclose the window area so as not to waste any light or get any glaring reflections inside and out. There are some 3rd brake lights available that go for $100+ for outside mount (mine was $16 JCW). You could, if you dare, develope your own 3rd brake light - say an LED trailer-type set-up (oval).

Now for the most important part. You will need a LOGIC CIRCUIT. Either get it with the light or order it separately if the light doesn't come with it (not expensive).. The logic circuit tells the 3rd brake light that it is only a brake light and not a turn signal (2 wire vs 3 wire 'amber' set-up). You will hook the logic circuit and 3rd brake light to either the left or right brake lights which also happen to be TURN signal lights.

Bill D

[theGman]

You might consider what I and probably many others have done:

Convert your trunk backup lights to brake lights. You have to change the bulbs/housings to add the extra wire, tap into the existing wiring and run the new ones up to the trunk lid via the original "path".

Someone on the other forum recommended, and I bought, a set of auxiliary trailer lights from I believe Nothern Tool; these included the housings, bulbs and wiring, and wasn't that $$$.

The red lenses are at Nostalgia Motors and are a direct easy replacement for the original clear ones.

I then went to Auto Zone and bought a pair of thin rectangular back up lights for about $20 and then....(this took the most time, but was "easy work") bent a pair old antique license plates (Virginia's are nice thick aluminum...not like the regular plates) to make a mount.

I then ran the backup wire to the new lights and mounted them vertically, one on each side of the rear plate and they actually look good, in spite of me doing it! Ha Ha Ha Also can see well when backing up.

I don't leave the backups on long, never have, but wasn't sure if the extra power demand on the new driving/backups would overload the fuse....so far, no problem.

This conversion is good for 2 reasons: Better brake lights and better backup lights.

I wouldn't mind adding a 3rd brake light also, but.....having done this conversion there is no rush and I can take my time and find a tastefully done 3rd light and not care if I ever can find one, since I don't want to junk up the look with an obvious add-on.

Paul G.

Edited February 20, 2008 by theGman

[jmenacker]

You might consider what I and probably many others have done:

Convert your trunk backup lights to brake lights. You have to change the bulbs/housings to add the extra wire, tap into the existing wiring and run the new ones up to the trunk lid via the original "path".

Someone on the other forum recommended, and I bought, a set of auxiliary trailer lights from I believe Nothern Tool; these included the housings, bulbs and wiring, and wasn't that $$$.

The red lenses are at Nostalgia Motors and are a direct easy replacement for the original clear ones.

I then went to Auto Zone and bought a pair of thin rectangular back up lights for about $20 and (this took the most time, but was "easy work") bent a pair old antique license plates (Virginia's are nice thick aluminum...not like the regular plates) to make a mount.

I then ran the backup wire to the new lights and mounted them vertically, one on each side of the rear plate and they actually look good, in spite of me doing it! Ha Ha Ha Also can see well when backing up.

I don't leave the backups on long, never have, but wasn't sure if the extra power demand on the new driving/backups would overload the fuse....so far, no problem.

Paul G.

Paul:

If possible, would you please post a pic of your rear end? Hmmm, better qualify that by asking to make sure its the Avanti's rear end with the modified lights.

Joe M

[wdaly]

Paul:

If possible, would you please post a pic of your rear end? Hmmm, better qualify that by asking to make sure its the Avanti's rear end with the modified lights.

Joe M

Paul makes some good points. I too have added auxilary back-up lights ('88 ones filled with water and blew-out over & over). May I recommend adding a standard relay to your back-up lights - if they are like mine they pull 110 Watts! To install relay you must run a power wire from battery to trunk.

As far as 3rd brake light and using the two original trunk lid back-up lights instead - please consider using metal/foil tape on the inside cavity where there really should be some kind of mirrored reflector. This will give you way more light. I actually converted mine to AMBER turn signals!

Bill D

[theGman]

I need that relay for sure.

I tried to send a pic of MY rear end, but it was cracked! Ha Ha Ha

Will try to attach a quick pic of the Avanti's rear....

[IndyJimW]

I am currently installing over 100 high output LED brake lights on a fleet of vehicles as an addition to their third brake light if equiped. It's oval, about 1/4" thick by 1 1/2" tall by 4" long and can be surface mounted or placed in a rubber grommet. The light is divided into two halfs and when you brake the light will first flash between sides and then light fully. This light is BRIGHT and VERY visible. It pulls almost no amps but needs to be wired to the third brake light or the brake light switch. I was going to get a housing or use the one I have on my '87. Monday I'll get the name of the company and the part # and maybe post some pictures.

Jim Wood

[theGman]

Joe,

Just curious: What is that little chrome circle under your left taillight? I'm assuming it's for an alarm?

Thanks, Paul

[jmenacker]

Joe,

Just curious: What is that little chrome circle under your left taillight? I'm assuming it's for an alarm?

Thanks, Paul

Paul:

That lock cylinder with cover appears to be vestigial. I had assumed that it was for manual trunk release. The trunk lock is currently electric with a release button inside glove box and was like that when we bought the car. None of the keys we have for the car fit the cylinder below the left taillight.

BTW, thanks for posting the pic of your rear light set up. I do like the idea of additional brake lights.

Jim, can you please post a pic of the LED array brake light project?

Thanks,

Joe M

Edited February 17, 2008 by jmenacker

[WayneC]

<snip>

Here's the deal. These lights are hard to come by anymore because all cars for the past 20+ years have had them installed - so who needs replacements? When I say hard to come by I really mean your choices are quite limited. Checker, Advance auto, Whitney et. all do have selections (do it by internet). Trouble is they don't always distinguish between inside/outside capabilities.

Make sure the light aims "straight-out" not down or up / this can be difficult if trying to mount inside the Avanti extreme-swept-angle rear window. If you do mount inside the light should pretty much 'enclose the window area so as not to waste any light or get any glaring reflections inside and out. There are some 3rd brake lights available that go for $100+ for outside mount (mine was $16 JCW). You could, if you dare, develope your own 3rd brake light - say an LED trailer-type set-up (oval).

Now for the most important part. You will need a LOGIC CIRCUIT. Either get it with the light or order it separately if the light doesn't come with it (not expensive).. The logic circuit tells the 3rd brake light that it is only a brake light and not a turn signal (2 wire vs 3 wire 'amber' set-up). You will hook the logic circuit and 3rd brake light to either the left or right brake lights which also happen to be TURN signal lights.

Bill D

I haven't done this, but 2 comments...

1) the fact that so many cars in the past 20 years have a third brake light may actually make it easier;

simply visit a junkyard where they let you wander around and you may find one you like that looks as if it will fit your Avanti ... in fact, you could make a cardboard template of the rear window slant from your car, bring it along and trial-fit it in a junk car that has a third brake light that looks as though it would work.

2) although a logic unit might be nice (it could allow you to do all your wiring in the trunk), I don't think you'd need one if you can isolate the stoplight switch output wire (designated #15 on the wiring diagram, a red wire with a white trailer) in front of the directional signal control (goes to a 6-wire body harness connector specifically for the turn signal control, under the dash at the steering column, so you could intercept it there)... splice into that wire and test your light, then run your new wire back under the carpeting alongside the main body harness (next to the driveshaft hump) and up behind the rear seat & under the rear shelf to where your new rear deck brake light will be mounted; then run a separate ground wire from there to the nearest frame ground, and install your new brake light.

Edited February 20, 2008 by WayneC

[IndyJimW]

Here is a picture of the truck socket lined with reflective tape.

My regular lights were modified by the factory for 2 bulbs each.

My '87 Avanti came with a third brake light, I believe it's from the Monte Carlo donor car. I just installed a LED bulb because the socket was melted, this is a problem with third brale lights so open up the used light before you purchase.

Jim Wood

[jeffdgale]

thanks eveyone for the input. I am planning to do all that is suggested and will post pic when done. thanks again.

[adamderosa]

I used a center brake light assembly from a Porsche 944 on my Avanti; it fits nicely at the top of the rear window and it looks good. If you don't want to search salvage yards for one new ones are available; here's a link to a vendor:

http://www.automotion.com/productpage.aspx...&pid=105012

Instead of wiring in a logic module, you can just wire the center brake light directly to the brake light switch. This will allow it to function with the brakes and hazzard flashers, but not with the turn signal.