355 Third Brake Light Howto

There is already a thread that goes into how to change bulbs in a 355 third brake light but I had to do a couple things different so figure this howto from my experience.

1. Remove the 4 screws that hold the third brake light and the mesh grill. I have the screws circled in red. There was mention of some cars having rivets that come into play that must be removed. I did not have that issue.

2. After removal use a 7mm socket to remove the two bolts, one on each side, that hold it onto the grill.

3. Peel away the thermal insulator from the outside to access the assembly.

4. Use a flat screwdriver of suitable width to separate the top and bottom halves of the assembly. I did this by prying apart one of the ends first then taking a smaller flat screw driver and prying the sides carefully. There are 6 tabs that must be pryed apart and they are not parrallel to each other they are slightly offset from each other. Take note of the orientation of the top and bottom. The sides are keyed (see red square) so you can't put them back together flipped 180 degrees.

5. From here you should have the top red translucent half and the bottom half holding the circuit board with the bulbs and bulb holders (not in my pictures). If you problem is simply a burned out bulb just pull and replace - it's as simple as that. Reassemble in reverse order. The adhesive I used for the insulation was contact cement.
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OK, here's where things got to be a little different for me. I didn't have a bad bulb - I had a bad solder joint on one of the bulb holders. I knew my problem was an intermittent bulb at the end so I reseated each one as I figured the problem was a bit of contamination of corrosion. When I got to the 7th one not only did the bulb come out but so did the bulb holder.

1. Remove the circuit board by using a flat screwdriver to raise it past the hold down tabs. There is one under every tab used to hold the two halves of the completed assembly together. See previous post. Be careful near the 2 pin wiring connector. Each pin for the connector has its own tab to hold it in place. You'll have to use a small flat screw driver to push the tab in and another screw driver to push the pin out.

2. Get your soldering gun out and at the very least resolder each affected connection. It's so easy to do you should just go ahead and hit each connection for all the bulb holders and pins. I got a little fancy and completed the soldiering across even the unsoldered sections (see image).

3. Reassemble and test.

The End.

One thing I should note is that the bulb is a Sylvania type 74 that can be acquired in any auto parts store. You can certainly experiment with the LEDs mentioned in past threads but in the spirit of keeping it simple I stayed with the same bulbs.
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Doh!
Thanks for pointing that out. It's dissapointing to know but I'd rather know than not know. I'll put it on my "to do" list.

 

Hey does anyone know what the part number of that riveted peice is? I looked at the parts manual and I think I found it but the pictures is a little vauge. Looks like it's part number 64679800. It's shown as #31 at http://www.ricambiamerica.com/article_info.php?articles_id=1404

 

Actually... looking at my photo above, I don't see any holes that a rivet would go through. Could someone take a photo of theirs so I can see the actual peice? Thanks a million!

 

I found a pic of it in another thread.
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