Interior Lights dead. Anyone BTDT?

island911 · 10-06-2019, 06:04 PM

Floors illuminate, as do the marker lights on an open door. The main cabin lights stay completely dark - no manual override.

I've checked the fuse (fine) but expecting it may be a control unit.

Anyone have/fix this problem?

island911 · 06:17 AM

And just like that... the lights are back working again.

No idea how long that will last.

island911 · 11-11-2019, 08:54 PM

work / don't work . . . :-/

Does anyone know where the control unit lives?

RNajarian · RNajarian's Garage

Not sure if this helps . . . A guy on Rennlist had a similar problem. Though his problem ended up being a bad fuse.

Could it be a relay? A bad battery? Or . . . Back in the day I bought a dimmer module from Performance Products for my 944. When it went bad the courtesy light went dark. Does the Cayenne have a similar module, and of course where is it?

https://www.renntech.org/topic/36648-cayenne-interior-lights-stopped-working/

Is this the part? Or one like it? (I think this one is from a 928) it is a light delay relay

island911 · 12-30-2019, 09:47 PM

Thanks for the reply. The problem persists - sometimes the lights work, sometimes not. :-/

I really haven't had the time to delve into it more. Maybe next year.

RSBob · RSBob's Garage

You pulled up the front carpets and checked for moisture? A lot of wiring runs under the carpet and can corrode if it is wet due to plugged cowl drains.

Also an old battery can be the blame for a host of issues. Check the voltage

island911 · 02-07-2020, 10:58 PM

Good thought. I've experienced plugged cowl drains before, years ago, but that made a sloshing sound. Also, with all this rain lately I expect that if there was a leak the windows would be often fogged on the inside.

The battery is in good shape, - I just recently parked it for two weeks with the alarm on, it restarted w/o issue.

Maybe there is a common ground that is flaky.

guru944 · guru944's Garage

Ground Loops in Electrical circuitry.

add 1n4001 rectifier diode(s) on leads to ground.

Works... Did this mod also for rear tail lights.
keep me posted....Later

stormcrow · stormcrow's Garage

Could be a bad relay as pictured. When they start to fail they sometimes act erratic. My girl friends mustang had that problem with the start relay. Sometimes when she turned the ignition to start the car nothing would happen. Did some research on youtube and replaced the relay. No more problems starts every time.