986Forum

Troubleshooting Rear Window Defroster - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Add to repair workspace

New repair projectOpen repair workspace

Original source

5 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHTroubleshooting Rear Window Defroster - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Leading reported evidence

Replace top

Performed · outcome unconfirmed

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

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 performed work without a confirmed outcome: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

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
The top has been replaced several years ago by the PO and it included the glass window with the defroster wires in it.
Original post Read captured discussion
Troubleshooting Rear Window Defroster - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Frequently discussed work

Check continuity of the defrost panel

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion
best thing to do would be to check continuity of the defrost panel.
Original post Read captured discussion
Troubleshooting Rear Window Defroster - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Read full discussion summary

Leading evidence: 'Replace top' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check continuity of the defrost panel' (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.

Read captured replies

1 matching discussions · 5 captured posts examined · 0 partial discussions

Compare 2 other evidence results

Check continuity of the defrost panel

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion
best thing to do would be to check continuity of the defrost panel.
Original post Read captured discussion
Troubleshooting Rear Window Defroster - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Test voltage

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion
I assumed you un-plugged the connector that plugs into the glass and tested the voltage?
Original post Read captured discussion
Troubleshooting Rear Window Defroster - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Frequently discussed actions (3)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Check continuity of the defrost panel

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion
best thing to do would be to check continuity of the defrost panel.
Original post Read captured discussion
Troubleshooting Rear Window Defroster - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Replace top

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that performed work without a confirmed outcome: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

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
The top has been replaced several years ago by the PO and it included the glass window with the defroster wires in it.
Original post Read captured discussion
Troubleshooting Rear Window Defroster - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Test voltage

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion
I assumed you un-plugged the connector that plugs into the glass and tested the voltage?
Original post Read captured discussion
Troubleshooting Rear Window Defroster - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Coverage and how to read this overview

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.

5 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

986Forum: 1 discussions

0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.

0 acknowledgements have no verified action link; they do not establish a repair result.

Generation: 20261027T053112Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

Hi there! The top has been replaced several years ago by the PO and it included the glass window with the defroster wires in it. However when powering up the switch on the dash, the switch light comes on but the window does not defrost. I hooked up a voltmeter to the drivers side window connection and it read 11.80 volts, but taking the same reading on the other side of the window (passenger) it reads zero. Should there be a voltage reading on that side? If yes, where might be the issue? Thanks in advance for any assistance. Be good, Kevin

POST 2Original post

I assumed you un-plugged the connector that plugs into the glass and tested the voltage? I assume you checked that the painted on heating wires are not scratched or look broken? Check fuse too, even though the light lights the fuse could also be blown. It's a very simple system, kinda like a toaster.

POST 3Original post

best thing to do would be to check continuity of the defrost panel. Many youtube videos on how to do this. It's no different then any defrost on any car. Suspect you have a break in the lines somewhere on the glass.

POST 4 / ORIGINAL POSTEROriginal post

Yes I did. And again today based on the advice I took off both leads to the glass and had a perfect 11.95 volts which leads me to believe it is somewhere on/in the glass.

POST 5 / ORIGINAL POSTEROriginal post

Thanks, I will do some research on youtube to see if I can find a fix.

This is a source reference. Confirm exact model applicability in the original material.