WRXdriver

Disclaimer: I know others have had cruise control issues and did try to search. I’m away from home with only a very slow LTE signal and no WiFi access. Website is glacially slow and I’m not even sure this will upload. Will happily accept a “search is your friend” flame if information or link is included.

My cruise control worked perfectly last fall, but after driving about 700 miles this spring I tried it for the first time last weekend and discovered it’s inoperative. Cruise control fuse is fine.

Possible relevant information 1: Over the winter I cleaned and lubed the pedal box. While doing that I discovered a torn master cylinder boot and left everything disassembled for a couple months while sourcing a replacement boot and finding time to install it. Is there a cruise control-related micro switch under the floorboard that I forgot about and failed to reattach?

Info 2: I installed Tores excellent HID headlights and LED taillights along with his Smart Ballast shortly after buying the car ~16 months/12,000+ miles ago. All the lights still work perfectly but I frequently drive the car in the rain and the suspension is pretty stiff. Is it likely water, vibration, or my installation has caused an issue with the ballast?

Info 3: The week before I discovered cruise didn’t work I installed Morimoto projectors. The low beams are great, but when I select high beams the shutter on both projectors stay down and the oem halogen high beam lamps come on. They should not function this way so clearly I’ve made an error. I would gratefully accept advice on that too, but for now mention it only in an attempt to be thorough tracking down cruise control problem.

Other factors: My winter projects included briefly removing both front seats, installing four new speakers and splitters in doors, replacing door handle gaskets on both sides, repairing both door pockets, and fitting Rennline drivers side floor board. During this work I had various fuses pulled and the battery disconnected multiple times, but everything besides cruise control and high beam appears to be working properly.

Thank you all in advance.

-Mark

BobbyT

Hi Mark,

My guess is that it is an issue with your rear LEDs or the ballast or the installation (aren't you glad I narrowed that down for you). My CC worked great for a while after initial installation of the rear LEDs with Tore's first version of the Smart Ballast. I now have V2 Smart Ballast, and CC was intermittent. I found a faulty solder joint in my installation, corrected that, and the CC works now.

And yes, there is a clutch micro switch that needs to be connected and functioning for the CC to work. It breaks the circuit and turns off the CC when you press the clutch. If you go to this link, scroll down one page, select 993 model and year, then drill down to main group 7, sub group 02, illustration 702-00, the micro switch is shown as item #18:

https://www.porsche.com/usa/accessor...originalparts/

TheOtherEric

Yeah you either forgot to hook up the microswitch under the floorboard or, more likely, it just needs some adjustment. BTDT.

993pbug

^ I agree with TOE - most likely an inadvertent disconnection of the micro switch in the pedal assembly. However, I saw a recent post by Tore where he suggested that adding just one of the original builds to the taillights would produce enough resistance for the CC to work - might be a quick way to narrow it down between the 2 potentials areas.

WRXdriver

I love Rennlist!-but a little surprised no one suggested that real 993 drivers don’t require sissy driving aids like cruise control. You guys feeling okay? Whether it’s used or not, any inoperative component grates on every single OCD nerve in my body.

I probably forgot the micro switch. If that doesn’t work I’ll swap an incandescent lamp into the tail lights to check ballast. I’ll be back soon to report success or look for more help.

Thanks again, I appreciate the advice.

-Mark.

Magdaddy

I would suggest getting the improved ballast from Tore. I did the full exterior LED swap, including 3rd(now 5th with euro fog kit)brake light kits. My cruise worked initially, but stopped late last year. I just added another ballast, per Tore...as some 993’s just don’t work well/at all with just one according to him.

Installed this week, just finished up a nearly 600 mile road trip, worked every time.

BobbyT

Magdaddy,

You and I have been chasing a similar problem. I too have full LEDs on the rear, including basket handle brake lights and Euro fog conversion to brake lights. I have a fear of being rear-ended by one of the horde of texting-addicted zombies on SoCal roads, so I want all the brake/tail lights I can get. Tore hadn't mentioned an additional ballast, but that may be the ultimate answer. I'm using V2 of the Smart Ballast now,so far so good, but Tore is still working on another one for me.

Where are your two ballasts located? My one is in the right brake light circuit. Not sure if location makes any difference...

Magdaddy

original ballast is rear right, fog conversion AND second ballast on rear left. Only time will tell..

I absolutely love the led brake lights, wow they illuminate. The modern lighting updates, Morimoto Bi-xenon projectors, LED hi beam, HID fogs, and full LED everywhere else exterior is a spectacular improvement.

I put over 700 miles on the car Friday thru today. Even jumped back in with my daughter for an Easter back road blast. Running so strong, sounding so awesome with Fister Stage lll’s, and the Fabspeed X pipe w/cats. Been DD’ing it for the last couple weeks also, as the fairly new to me Cayenne GTS has been in the shop.

It’ll be 9 years of ownership this Memorial Day, still amazes me with every drive, and every glance.

fatmike

Before chasing all of this, just replace the brake light with an incandescent bulb and see if your cruise works. If it does, then you know your issue and you can figure out your LEDs...

/

BobbyT

Magdaddy,

Gotta ask about that "assless chap's bonnet mod"...what is that?

kevin2012

I had the same experience before after changing to LED brake light. Changed back to stock brake light bulb, cruise control worked perfectly again.

WRXdriver

I said I’d report back. As suggested cruise control inoperative because the arm on clutch pedal micro switch is misaligned. Must’ve happened when I replaced master cylinder boot, but not sure how.

It’s pretty tough to reach in there so to verify the problem I just extended the arm about 1/16” with a low-tech piece of Gorilla Tape. CC functioned long enough to verify the issue, but I have no idea how I’m going to permanently realign the arm. On the other hand, if I remember correctly from my grade school days, GI Joe used to tell us that, “Knowing is half the battle!”

In general I feel pretty confident following the advice of a low budget cartoon character from the 80’s, but I don’t specifically recall him ever standing on his head in a sweltering hot garage trying to work on a ridiculously cramped and overly complex pedal box. Probably just missed that episode.

Thanks everyone.

-Mark