Thumping in tail when headlights switched on!

[itzbob46]

Stopped in a parking lot ...... parking lights already on........switched on headlights and heard a rapid thumping sound in the tail end. Beats were 2-4 per second and loud enough th scare the heck out of me. It stopped when I turned the headlighs switch off. I then shut the car down and looked out back to see if the spoiler had done something funky. all looked normal and the spoiler operated manually as it should. I restarted, turned on the headlights and all was wel lagain.

Any ideas......? Sure sounds like the spoiler did something. What else is back there that could thump?? If that happened on the highway I'd be paniced.

Bob

[Sboxin]

Stopped in a parking lot ...... parking lights already on........switched on headlights and heard a rapid thumping sound in the tail end. Beats were 2-4 per second and loud enough th scare the heck out of me. It stopped when I turned the headlighs switch off. I then shut the car down and looked out back to see if the spoiler had done something funky. all looked normal and the spoiler operated manually as it should. I restarted, turned on the headlights and all was wel lagain.

Any ideas......? Sure sounds like the spoiler did something. What else is back there that could thump?? If that happened on the highway I'd be paniced.

Bob

Bob,

Don't panic...but this one is a stumper...never heard this problem before :huh:

IIWM - I would wait for another occurance of the thumping and then check further for failed parts or functions.

You might have just scared an animal under the car or some other weird thing happened, not related to the car itself.

Take care,

Ed

PS: I answered because no one else did :cheers:

[silver arrow]

It's just the hooker that you stuffed in the trunk. If you let her out or feed her the thumping will stop. If you don't do anything she'll eventually stop thumping too.

Edited August 20, 2008 by silver arrow

[itzbob46]

Thanks, Guys. Well, 60 people looked at this post and didn't know what it could be! It hasn't done it again since, but one thing I know for sure......if it electrical/electronic and on a Porsche, it will eventually do something really wierd. I can make a list of weird occurances....Porche should hire a Japanese electrionics engineer!!!!!!!

Bob

[itzbob46]

Thanks, Guys. Well, 60 people looked at this post and didn't know what it could be! It hasn't done it again since, but one thing I know for sure......if it electrical/electronic and on a Porsche, it will eventually do something really wierd. I can make a list of weird occurances....Porche should hire a Japanese electrionics engineer!!!!!!!

Bob

Spoke too soon.... just did the thump thing again. This time I let thump and checke dit out. Appears to sound like a relay in the spoiler.........lile I said above...headlights affecting a spoiler!........only Porsche could do that!

[Beelzy]

Hmm, sounds like the wiring harness in the trunk should be examined for damaged wiring? That is weird.

[wvicary]

The ignition switch can cause odd electrical problems but I've never heard of anything like this before. I assume the battery/charging system is operating correctly. Any signs of water migration/wet carpets??

So is it the relay making the noise or is the spoiler actually moving and causing the noise?

[itzbob46]

The ignition switch can cause odd electrical problems but I've never heard of anything like this before. I assume the battery/charging system is operating correctly. Any signs of water migration/wet carpets??

So is it the relay making the noise or is the spoiler actually moving and causing the noise?

I placed my hand on the spoiler while this was happening... if only shutters from the thump. It doesn't move. I have to take off the inner panelling to see what is actually in there. I say relay, but I'm not sure what's behind that rear panel on either side of the trunk latch.

I think I'll be undoing the HID kit (CQ Light) since all of my electrical troubles started with the installation of that kit......CQ Light couldn't offer any advice. If that turns out to be the problem cause I'll push them for a full refund.

Any more ideas?

Bob

[Chippy]

Now that's interesting that you mention HID, because I occassionally get the same noise - when I first did i thought it was the engine about to let go!

I put it down to my HID kit, because switching the lights off and on again seems to cure the noise.

[itzbob46]

Now that's interesting that you mention HID, because I occassionally get the same noise - when I first did i thought it was the engine about to let go!

I put it down to my HID kit, because switching the lights off and on again seems to cure the noise.

Chippy ... See PM that iI sent you.

Bob