Date: Sat, 09 Sep 2000 12:57:30 GMT From: drc <drc.dotnopsamwa.com> Subject: Re: Apply the breaks, all lights go on!!
This is a known problem that has been covered here in the past -- the ground connection to the rear lamp cluster has corroded. It happened to my '94 900 twice. When the ground connection fails, the current passing through the brake lamps has to find an alternate path to ground, and hence it flows through all the other bulbs. That's why the other bulbs light up when you step on the brakes. The corroded connection is inside the multi-wire connector at the back of the taillight lamp assembly. You might not even realize that the multi-wire fitting at the back of this lamp assy is in fact a removeable connector. There are two fixes: 1) you can unplug the multi-wire connector from the lamp housing and attempt to remove the corrosion. You'll need a tiny fine file, or a narrow blade. I used some old dental picks and scaling tools. It will be on the connector pin and socket that terminates the black wire (I think it was pin 7). However, it can be extremely difficult to remove the connector. It took me quite a bit of juggling, prying and persuading to get the connector plug to come out. 2) A few year's after making this repair (above), the problem returned. My dealer's solution was to add an additional ground wire that bypasses the multi-wire connector. This is done by removing the rear of the lamp assembly (as if you were replacing a bulb) and identifying the ground track. It is the metallic track that daisy-chains around the backplane and runs to each of the bulbs. Drill a 1/8" hole through the back adjacent to the ground track. Feed a black wire through this hole (18 ga or so) and solder one end to the ground track. Connect the other end of the new ground wire to a solid part of the metal chassis below the tail light assembly. You'll find an electrical ground connection behind the carpet near the midline of the trunk, below the taillights. Make the bypass ground wire long enough so it doesn't interfere with changing bulbs in the future. Make darn sure you have soldered the wire to the ground track in the lamp assembly. If you've grounded one of the other tracks, you will blow a fuse, and/or start an electrical fire. No warrantee expressed or implied. Do at your own risk. I had to perform this surgery on both rear light assemblies during the 14 years I owned my '84 900. Good luck - DRC > > Kyle Kontney wrote: > > > I have a 1985 SAAB 900 Turbo, 4-door that I took on a trip. During my > > trip, > > something wierd happened.... When I apply my brakes, all the > > directional and > > tail lights light up.... Dimly, but they light up. All of them; > > Reverse, > > directional, brake lights and running lights - even the front > > directional > > and turning lights! > > > > I checked all relays and fuses that were in the fuse area (under hood). > > Any > > clues would help. > > > > -Kyle >
 |
 |
 |
 |
 |
