14 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHC4S odd tail light issue
Reported or suspected cause
broken center contacts
Reported cause
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
0
Reported fixes
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that report identifying a cause
1
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0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Reported cause
My issue was the broken center contacts which was an easy diagnose and fix.
Leading evidence: 'broken center contacts' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'broken center contacts' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check fuses (a3 and a4) and they are fine' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
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0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed · Original poster
I checked the fuses (A3 and A4) and they are fine.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
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Performed · outcome unconfirmed · Original poster
I removed the assembly and inspected the bulb housing more closely.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
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Performed · outcome unconfirmed
I ended up replacing both taillight wiring harnesses.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
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Performed · outcome unconfirmed · Original poster
Both filaments worked when I tested the bulb in the driver's side tail ("light on" state, "brake on" state).
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Suggestion
If you have power at one spot and not the next, start breaking that subsystem into smaller chunks and testing the smaller sections - you are likely to narrow it down to a single wire run, fuse, relay, connector, pin, etc.
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0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Next, I'd start working my way back along the circuit: is the contact on the bulb socket corroded, do you have power at the contact in the socket (you can use a test light if you don't have a multimeter)?
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
14 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 1 excluded by outcome qualification · 0 adjusted by outcome qualification.
2 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
Most of the time it boils down to a simple, easily fixed problem.
I've just noticed something odd going on with my passenger tail light... This is what happens, when the lights are on:
The brake light bulb works when I apply the brake, but the bulb goes out completely when I take my foot off the pedal. There are three lights in the tail light assembly: the brake light, the center light and the side marker. The center light and the side marker work fine. I tried the offending bulb on the driver's side and it works as it should so I know it's not the bulb that is faulty.
I checked the fuses (A3 and A4) and they are fine. I was thinking the issue might be with the harness, or the bulb holder. What stumps me is that the bulb actually gets power since it works when I depress the brake pedal...
Does anyone have any ideas?
When you changed the bulb did you look into the socket to see if the center contacts were not broken. When I bought mine there were three sockets that the center contacts had broken off. Might want to peek in just to be sure. Also, does wire harness look good.
Thanks for the suggestions, I will take a closer look when I get home from work. Question: did you end up replacing the sockets or did you manage to repair them?
Sounds like you've eliminated the bulb as the culprit since both filaments work in the other side socket. You also eliminated the brake switch as the culprit since it causes the other side to illuminate when the brake is depressed. Sounds like you've isolated it to a single circuit, and ruled out the bulb. Am I following so far?
One thing you mention that may be leading to a faulty assumption is around power. Each of the filament circuits runs off a different independent circuit/power wire, so the fact that your marker works and your brake light doesn't is consistent with one of those (the brake circuit) having a bad connection. Your marker light circuit to that lens may be fine and the brake circuit may have a fault.
Next, I'd start working my way back along the circuit: is the contact on the bulb socket corroded, do you have power at the contact in the socket (you can use a test light if you don't have a multimeter)? Is the connector firmly seated? Are all of the connector pins intact and straight?
If that all checks out, I'd start tracing the circuit back in large chunks, and then narrowing in from there.
Do you have power at the connector behind the light? Do you have power at the connection to the fuse box? If you have power at one spot and not the next, start breaking that subsystem into smaller chunks and testing the smaller sections - you are likely to narrow it down to a single wire run, fuse, relay, connector, pin, etc.
Then clean, repair, fix or replace the damaged component.
I ended up replacing both taillight wiring harnesses. If you find thats the problem search for prices on replacement harnesses because some must be gold plated based on asking price!!
Thank you both for your replies. You've given me good avenues to investigate and I will report back.
Cds: one small clarification - the brake light works, it's the marker that doesn't.
Sorry, I read it wrong (or maybe wrote it wrong). The same technique works either way. The good news is that there are even fewer components in the marker light circuit.
It's the same troubleshooting concept whether you're debugging software or an electrical problem. Break the problem up into smaller sub-segments, and iteratively reduce the span of the testing until you isolate the anomaly.
Personally, I would not start buying harnesses or parts and throwing them at the problem until you figure out what is wrong. I see this way too often.
Most of the time it boils down to a simple, easily fixed problem.
Yep, I used to be a RR locomotive electrician at the start of my career so troubleshoot first, don't throw parts at it. Look for the easiest things and don't get mislead by thinking it's something technical until that is where it leads. I always went "upstream" from the problem to prevent jumping around and becoming confused. My issue was the broken center contacts which was an easy diagnose and fix.
Reporting back...
I removed the assembly and inspected the bulb housing more closely. One of the two contacts, which is a small piece of sheet metal folded over itself, was partially broken off (only the top "fold"). Working carefully with a pair of needle nose pliers, I was able to modify the bend in the remaining piece such that it now rises higher in the housing and makes solid contact with the base of the bulb. Problem solved!!!
Thank you both again for sharing your wisdom and expertise, it allowed me to fix the issue in about 10 minutes at no cost.
Merci beaucoup!
