I am having trouble with the 3rd brake light.
Trouble getting the 3rd brake switch to work.

The brake switch under the dash is good. I have power at the connection of the blue wire with the black stripe.

I found the blue wire with black stripe is cut off on the upper rear portion of the hatch.

Not sure where this is supposed to connect to. Does this connect to the gas strut electrical connection.

The orange wire at the lower part of the back panel has power.

Confused?

 

The connections on the gas strut are for the heater grid on the window

 

That is what I thought but now to figure where the cut Blue with black stripe wire goes to that is cut at the area of the left rear hatch strut.
Wire comes from the two brass spring contacts in the upper portion of the decklid.

 

I looked through the 86 service manual. Is it light blue with the black stripe?
Do you have a digital dash?

 

Yes,

From the two spring contacts on the upper part of the hatch. There are two wires one black and one light blue which goes into a connector and out of this comes a wire that is light blue with black stripe. This wire light blue and black looks to have evenly stripes. This is the wire that is cut.

I believe the when the door is closed the 1 and 4 contacts provides power through the spring contacts which feeds through both the blue and black wire connecting to the light blue and black striped wire.

I have been looking at the service manual as well but so far no luck.

 

How about some pictures?

 

Pictures attachec

Picture of upper hatch

 

That's the high mount/3rd brake light for sure. That might not be the original hatch on the car and why the color of the wire is different. That should be attached to the wiring for the bulb for the middle light. What is the problem exactly?

 

Where does the blue wire hook up to?

There is not a direct wire to the third stop light.

The 86 third brake light has four bulbs and is connected to the hatch glass by two brass washers/nuts in which the circuit connects to the glass somehow.

The circuit is through the glass somehow and I do not find the other end of where this blue wire was cut from.

It is the original hatch and has the urethane spoiler.

 

You need to help yourself now. I can't see what you have, have you taken the 3rd light apart and looked at it? Pictures? oh yeah, one more thing, more pictures. More pictures

 

Yes I have and everything is good on that end.

I believe after 1986 they went to a direct wire to the third brake light instead of through the glass circuit.

Will get more pics.

Since I live in Lincoln, Ne I am going to visit Restore A Muscle Car nearby and ask them.

In our family we have four classic Firebirds.
1969 Firebird 400 matching numbers in excellent condition.
1979 Firebird Trans Am all original matching numbers in excellent condition.
2002 Firebird Trans Am Collectors Edition with less than 30,000 miles on it.
This car a 1986 Firebird Trans Am is basically a daily driver type of vehicle.

 

Is the 3rd brake light high up on the glass?

 

Yes.

There are two holes about 3/4 inches in diameter in the glass with brass washers laminated to the glass.

the light assembly is bolted through the holes in the glass and makes contact with the brass washers with brass bolt/washer combination completing the circuit.

 

Then I don't think that decklid is original to the car or someone changed something. Later cars had the 3rd light under the spoiler and the contact for the light was in the interior panel and that wire would have gone to the light

 

I found the problem. I am missing the connection that is attached to the rear window Glass. The power wire that is cut connects to this connection and the black wire from the connection connects to the rear left hand strut connection at the trunk end. Now I have to find this piece and attach to the glass.

 

Does the wire simply run up the side of the glass up to the 3rd brk light? Seems like that be too easy to get caught in something.