adding a 3rd brake light on a 85
04-24-2010, 05:34 PM
#1
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adding a 3rd brake light on a 85
I have a 85 that I am wanting to add the 3rd brake light. I already have the housing, what I am trying to figure out now is what wires do I tap into, so far the only way I can get it to light up is if I am on the yellow and black or green and black. Problem with that is, when the turn signal is on the 3rd brake light blinks. Anyone know what wires to tap into? Thanks
04-24-2010, 05:49 PM
#2
Team Owner
The 3rd brake light on the 86 and later cars had it's own wire that went to the brake light switch. Later switches had a different connector to accommodate the wire and connector. You will probably have to run a dedicated wire from the existing switch back to the light.
04-24-2010, 05:59 PM
#3
Le Mans Master
04-25-2010, 11:43 AM
#5
Safety Car
The 3rd brake light on the 86 and later cars had it's own wire that went to the brake light switch. Later switches had a different connector to accommodate the wire and connector. You will probably have to run a dedicated wire from the existing switch back to the light.
I think the idea is in case something happens to your other brake circuit, this one still works. Well that and to have an additional brake light at eye level that hopefully someone will see befor they smash into you. Unfortunately even on the coupe this light aint any higher than most normal brake lights.I have an '85 too and I will eventually add the third light I got with a trade vette. I will run a dedicated wire to it.
04-25-2010, 12:36 PM
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04-25-2010, 02:05 PM
#8
I think the idea is in case something happens to your other brake circuit, this one still works. Well that and to have an additional brake light at eye level that hopefully someone will see befor they smash into you. Unfortunately even on the coupe this light aint any higher than most normal brake lights.I have an '85 too and I will eventually add the third light I got with a trade vette. I will run a dedicated wire to it.
04-25-2010, 02:50 PM
#9
Safety Car
04-25-2010, 05:20 PM
#11
Burning Brakes
Beyond running a wire to it you also have the problem of actually Mounting the '86 and newer lamp housing onto the '84-85 hatch. The bolting for the housing will interfere with the hatch glass, which was cut out/contoured to clear the 3rd brake light when it was added to the cars in 1986.
It was done to My '85 by the PO (or he had it done..), and done poorly by basically epoxy-ing studs onto the housing further forward than they should be so that they could go into holes drilled into the hatch hinge plate and miss the glass. Poor answer, one which I ultimately had to fix by flame cutting a mounting plate and thereby getting something a bit better.
The "right" answer, of course, would be to change out the hatch for an '86 or newer..
It was done to My '85 by the PO (or he had it done..), and done poorly by basically epoxy-ing studs onto the housing further forward than they should be so that they could go into holes drilled into the hatch hinge plate and miss the glass. Poor answer, one which I ultimately had to fix by flame cutting a mounting plate and thereby getting something a bit better.
The "right" answer, of course, would be to change out the hatch for an '86 or newer..
04-25-2010, 10:56 PM
#12
Race Director
Beyond running a wire to it you also have the problem of actually Mounting the '86 and newer lamp housing onto the '84-85 hatch. The bolting for the housing will interfere with the hatch glass, which was cut out/contoured to clear the 3rd brake light when it was added to the cars in 1986.
It was done to My '85 by the PO (or he had it done..), and done poorly by basically epoxy-ing studs onto the housing further forward than they should be so that they could go into holes drilled into the hatch hinge plate and miss the glass. Poor answer, one which I ultimately had to fix by flame cutting a mounting plate and thereby getting something a bit better.
The "right" answer, of course, would be to change out the hatch for an '86 or newer..
It was done to My '85 by the PO (or he had it done..), and done poorly by basically epoxy-ing studs onto the housing further forward than they should be so that they could go into holes drilled into the hatch hinge plate and miss the glass. Poor answer, one which I ultimately had to fix by flame cutting a mounting plate and thereby getting something a bit better.
The "right" answer, of course, would be to change out the hatch for an '86 or newer..
I removed mine a couple of years ago when I changed to a different rear bumper but still used the module for the in bumper mounted 3rd brake light.
04-25-2010, 11:18 PM
#13
Safety Car
383, I think folks would have a hard time catching you, much less actually getting close enough to hit ya!! 
Did you tap into the wiring at the back of the car? You shouldnt have a problem with it if its a dedicated line.
I have seen plenty of cars that the third light was the only thing working and it saved em from having my GMC truck impaled in their azz. Remember I live in Bama, no vehicle inspections here and honestly the third light is enough legally, only one required here.
Did you tap into the wiring at the back of the car? You shouldnt have a problem with it if its a dedicated line.I have seen plenty of cars that the third light was the only thing working and it saved em from having my GMC truck impaled in their azz. Remember I live in Bama, no vehicle inspections here and honestly the third light is enough legally, only one required here.
04-26-2010, 05:12 AM
#14
Burning Brakes
The hatch is the same for an 84 and 85 as it is for an 86 on. I added a third brake light years ago on my 84 and it fit perfectly.
Apparently the installer had the same thought, which is why he cut the stock studs off and used epoxy to attach them differently. Which worked, for a couple of years at least.
Or Something.. All I know for sure is that I had to futz around with the thing to cobble up a better solution, one which Still isn't "stock", but works.
04-26-2010, 08:34 AM
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Beyond running a wire to it you also have the problem of actually Mounting the '86 and newer lamp housing onto the '84-85 hatch. The bolting for the housing will interfere with the hatch glass, which was cut out/contoured to clear the 3rd brake light when it was added to the cars in 1986.
It was done to My '85 by the PO (or he had it done..), and done poorly by basically epoxy-ing studs onto the housing further forward than they should be so that they could go into holes drilled into the hatch hinge plate and miss the glass. Poor answer, one which I ultimately had to fix by flame cutting a mounting plate and thereby getting something a bit better.
The "right" answer, of course, would be to change out the hatch for an '86 or newer..
It was done to My '85 by the PO (or he had it done..), and done poorly by basically epoxy-ing studs onto the housing further forward than they should be so that they could go into holes drilled into the hatch hinge plate and miss the glass. Poor answer, one which I ultimately had to fix by flame cutting a mounting plate and thereby getting something a bit better.
The "right" answer, of course, would be to change out the hatch for an '86 or newer..
04-26-2010, 10:10 AM
#17
Race Director
383, I think folks would have a hard time catching you, much less actually getting close enough to hit ya!! Did you tap into the wiring at the back of the car? You shouldnt have a problem with it if its a dedicated line.
I have seen plenty of cars that the third light was the only thing working and it saved em from having my GMC truck impaled in their azz. Remember I live in Bama, no vehicle inspections here and honestly the third light is enough legally, only one required here.
Did you tap into the wiring at the back of the car? You shouldnt have a problem with it if its a dedicated line.I have seen plenty of cars that the third light was the only thing working and it saved em from having my GMC truck impaled in their azz. Remember I live in Bama, no vehicle inspections here and honestly the third light is enough legally, only one required here.
04-26-2010, 09:26 PM
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I installed one on my 85. I ended up routing from the brake switch to the rear of the car. the main problem you will run into, is the glass on the rear hatch overlaps where the mounting holes need to be drilled. because of this, you have to attach 2 bolts (i used high strength epoxy) roughly 1" back from the original mounting holes. this way, you can drill through the hatch, missing the glass entirely. I can post pics if needed.
04-27-2010, 02:09 AM
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thanks for all of the input. I still cant decide if it is going to be worth all of the trouble...lol I have one of each of the 3rd brake light housings, one for the roof and one for the bumper. I have never been a fan of the looks of the one on the roof so IF I do add it I will use the one that goes in the bumper. Thanks again
04-29-2010, 02:16 AM
#20
Safety Car
There's already a wire in your harness for the third brake light, that comes directly from the brake light switch. This wire is light blue, and goes to the connector for the rear body wiring, pin B of a 15 pin connector. There is no wire at pin B in the rear body wiring harness. I think this connector is located below the right side rear compartment courtesy light.
This wire was used for European 'vette's that had amber rear turn signals and dedicated brake lights, rather than the dual purpose brake/turn USA style lights.
This wire was used for European 'vette's that had amber rear turn signals and dedicated brake lights, rather than the dual purpose brake/turn USA style lights.