How sophisticated is SAAB's lamp sensing system? - Saab 9-5 Bulletin Board - Saabnet.com
Click Banner for Details on this Saabnet.com Classified
Site News -
7/20 New Member Feature: Fewer Ads in Classifieds & More |
7/20: Saab Convention Photos |
7/11: Saab Photo of the Year Winners |
New Feature: BB Daily Digest Email
NG900 & OG93 |
Vintage Models |
Clubs & SOC |
Other Cars |
Member Photo Galleries |
Member Directory |
*Buddy Registry |
*Mileage Registry |
What's New |
Photo of the Month |
I have a problem with the right tail light not illuminating on my 9-5. It first appeared about 18 months ago when I replaced all lamps in both rear cluster, then miraculously resolved itself within a week. Not really, but the lamp worked.
The problem reappeared again after manipulating the wiring harness to the right rear lamp cluster to verify wire colors to connect my trailer harness. I 'assumed' there was an issue with a bad crimp in the lamp board wiring harness connector body (which cannot be repaired) or a break in the Pink wire near the board/connector that provides the tail light power to the right rear.
My plan was to jumper around the break by splicing into the wire and placing a screw terminal on the lamp board conductor bar going to the lamp. I was trouble shooting this morning prior to installing the jumper by exposing a short section of the pink wire in the spare tire well, slitting its insulation, and placing my 12V test light probe on the bare conductors to validate power is there.
Naturally, by the time I turn on the headlights, wait for the SID alarm message, clear the message, run around the car to the trunk area, and insert my test light in the slit, there is no power!
Two possibilities jumped to mind:
1) the break is elsewhere in the trunk area. or
2) the lamp sensing circuity with Orange Relay is sophisticated enough to interrupt power to what the car sees as a non-function lamp.
I swapped Orange Relays with my Viggen when this problem occurred earlier with no change in error, so I am 90% certain it is not an Orange Relay issue.
Guess I will drag my wife out to the drive way to turn on the lamp switch while my probe is inserted. Maybe I will see a flash of its light. After testing the tester on a Brake lamp signal to verify the tester is working.
2008 9-5 Aero Sedan, sold at 227K miles
2006 9-3SC 2.0T - Wife's daily driver
2000 Viggen Convertible - Summer Fun Car
1964 Quantum IV Formula Car - Retirement project
2000 9-5lpt Sedan, sold at 318K miles
Posts in this Thread:
- How sophisticated is SAAB's lamp sensing system?, MI-Roger , Sun, 31 May 2020 07:24:04 <-- Viewing This Message
- Fuse #4 in dash board fuse block?, MI-Roger , Wed, 24 Jun 2020 11:52:18
- taking a tangent..., AeroEd , Wed, 10 Jun 2020 14:24:36
- Re: How sophisticated is SAAB's lamp sensing system?, SWEDECAR , Mon, 1 Jun 2020 08:01:15
- More diagnostic results. Opinions solicited....., MI-Roger , Sun, 31 May 2020 08:21:57
Post a Followup
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
This is a moderated bulletin board - Posting is a privilege, not a right.
Unsolicited commercial postings are not allowed (no spam). Please, no For Sale or Wanted postings, SERIOUSLY.
Classifieds are to be listed in The Saab Network Classifieds pages.
This is a problem solving forum for over 250,000 Saab owners, so expect to see
problems discussed here even though our cars are generally very reliable. This is not an anything goes
type of forum. Saabnet.com has been a moderated forum since 1988. For usage guidelines, see the
Saabnet.com Mission and Purpose Page. Please remember that you are
not anonymous. Site Contact | Site Donations | Other Sites by SP -
Your address is: 220.127.116.11 - Using CCBot/2.0 (https://commoncrawl.org/faq/) - Logged.
Site Members do not see red text instructions, bottom of the page anchor ads, or box ads.
Click here to see all
the Site Membership Benefits!