LIGHTING PROBLEMS IN 4 DOOR 900s

If your 4 door classic (79-83 900 and 94 Convertibles) does strange things when using more than one warning light system at once, say you are giving a turn signal and when you hit the brakes, the turn signals stop, then you probably have a bad ground at the rear light assemblies. Saab piggy backs the ground from the left side to the right side and the pin in the left assembly often gets hot and burns. The following is a way to repair the problem so that it never occurs again and without buying new light assemblies.

2 small bolts about one inch to an inch and a half long. No bigger than 6 mm, 4 mm works great.
6 flat washers to for the bolts
2 nuts to fit the bolts
About 5 feet of wire, preferably the same gauge as the cars lighting harness, or one size larger
4 eyelets to fit the wire and the bolts
Contact Cleaner
Possibly Bulbs for the rear assemblies

                     TOOLS REQUIRED

Small flat screwdriver
Small sharp pick, an awl or ice pick will suffice
Wrench and socket with ratchet to fit the bolts above
Drill Bit to drill a hole to fit the bolts
Drill
10 mm socket or wrench
Phillips screwdriver  

Raise the trunk bottom panel and secure it so you can work. Remove the two plastic clips retaining the cardboard cover across the rear of the trunk. The clips are in the bottom corners and will just pull out. Go to the left tail light assembly and remove the connector from the assembly. Release the assembly by pressing the two tabs on its sides. Do the same for the right assembly.

Look at the pins on the assembly. You will notice the second one on the left assembly has a discolored pin and evidence of melting in the plastic. Take a small flat screwdriver and scrape off the pin as best you can. Flip the assembly over remembering where the burnt pin was on the assembly. Trace that pin's metal circuit to a square about one inch by one inch that is along its path. Drill a hole through this square and through the underlying plastic. Don't center the hole in the square, it has to off center a bit to clear the plastic reinforcements behind it and give enough room there for your washer and nut to fit.

Strip each end of your new wire and crimp an eyelet to each end securely. At this time, do not worry about cutting the wire to a specific length. Put a washer on a bolt, pass the bolt through the hole you drilled so its head comes in contact with the metal square, then on the other side first put another washer, then an eyelet you secured to the wire, another washer on top of that, and then tighten it all down with a nut. Make sure the eyelet is turned so the wire can exit at the slot in the assembly for the other wires. Repeat the process for the other assembly, using the eyelet on the other end of your wire.

At this time, check the condition of the contacts on the bulbs in the assemblies. If they appear flattened or pitted, its a good idea to replace them. Using the pick or awl, pull up on the contacts for the bulbs in each assembly to tighten the connection. Be careful not to let the ones with two contacts touch or change alignment, just bend them slightly up. A good cleaning with contact cleaner helps. Install all your bulbs.

Clean the pins next in the assemblies. Scrape the ones that are badly oxidized and clean further with contact cleaner. Then reinstall the assemblies in the lens. Look at the center of the back of the trunk (where the cardboard was) and find the center support. Loosen one of the bolts and remove it. take the awl or pick and scrape away the paint under this bolt. Clean the area with contact cleaner as well as the bolt. Route your wire so it will lie behind the cardboard cover and cut it so that both ends from either side end up at this bolt. Allow a little extra wire so it won't be tight. Strip the ends and crimp on the other two eyelets to each end and anchor them to the hole you scraped that the bolt came from.

Now have a go at the connectors for the assemblies. They will separate with a flat screwdriver. Just be careful not to pry on any of the pins when you are separating the two halves. Once you get them apart, gently clean them and spray with contact cleaner. Tighten them up a bit by bending them gently outward, but be careful not to go too far. Just a bit is all they need. Then put the halves of each side back together by aligning the grooves in one half with the slots in the other. Make sure the pins on each half face each other. Then reconnect them to the assemblies. You can orient them correctly by remembering that the second pin was the burnt one and the black wires in the connectors go to that pin.

Check all the lights now and make sure they work. Then button up the trunk area and you are done. Takes all of about 15-30 minutes and costs very little as opposed to replacing the assembly and just having it happen again in a few months.