Sutts74

Can someone help me figure out this problem.

1.If i turn on the lights with no key, the car will begin to prime itself (usual startup sounds but won't try to turn over) is this normal?

2. I also have power to radio with no key in ignition.

3. My front orange marker lights stay on with lights off / car running. But work properly when signaling.

How should I begin to trouble shoot?

phoneyman

I recently had some electrical problems myself and explored the car a bit. Take my answers with skepticism, but hopefully it can help a little before someone smarter joins in.

1) That does not sound right and my car does not do that. If the "priming" sound is the fuel pump turning on, it could be a short to the pump.

2) With my aftermarket head unit and crutchfield wiring harness, my radio does not have power if the ignition is off. But I have had problems with the radio power in the past so not sure on this one.

3) My signal lamps do not stay on unless I am signaling. Is the car of Canadian origin? I know on my Audi the Canadian version has daytime running lights that can be activated without the lights being on.

GC96

1) My car doesn't make any sound with no key and the headlight switch on. It might help if you could isolate the sound to a particular system (i.e. is it the fuel pump, the brake hydraulic booster pump if you have a C4,...)

2) I do have power to the radio with no key in the ignition. I believe my radio will automatically turn itself off after 1 hour under this circumstance but I have never tried this. I know this (not wiring the radio to the ignition switch) was a common trait for VW/Audi cars through the '90's and I think Porsche was similar as well.

3) My car doesn't do this but it is a US spec car without daytime running lights. I'm not sure exactly how the daytime running lights were wired up so this may be normal, presumably someone else with a Canadian spec car might be able to help.

GC

Sutts74

Thanks for the replies. I'm a mid level Diy'er but not so familiar with electrical. How would I go about detecting a possible short in the fuel pump or anything else for that part.

phoneyman

Electrical problems can be hard to track down even for seasoned veterans. You should do an exhaustive search through previous posts, 1 problem/question at a time. The information has most likely been talked about before on this site.

If you dont have one already and are going to be DIY in the future, you could also purchase the Bentley repair manual. It has a lot of electrical diagrams that will help you track down the potential problem and learn as you go.

william_b_noble

first, is this car new to you or have you owned it for a long time - if new, I have seen massively butchered electrical systems - the idiots who install stereos and alarms clip and short all sorts of wires. If you have had it for a long time, what changed?

Second, you want to get the schematics, they are not the easiest thing to read, but without them it is pretty hopeless.

If the car is new to you, and it has an aftermarket stereo, I'd start there, pull it out and look at the wiring. it's just astounding what they can mess up.

Sutts74

I've had the car for 3 yrs now and it has the stock radio. The car runs great just one of those things that's always been bugging me. However there is a GPS unit hard wired by previous owner. I guess I'll start with that first.

william_b_noble

For the 12 years or so that I had my 993, I had no electrical problems - SAI problems yes, but electrical no - so I would start with where modifications were done - hooking the GPS to the wrong power lines could easily do what you report - fool the computer into thinking something is on when it isn't due to bleed currents through the GPS unit.

pp000830

1.If i turn on the lights with no key, the car will begin to prime itself (usual startup sounds but won't try to turn over) is this normal?

You may be hearing the climate control system fan. It seems to me that if you are not having operating issues or a drained battery over night you may not have an issue here

2. I also have power to radio with no key in ignition.
Some German cars keep the radio and the windows powered until one of the doors is open. Not sure if some 911 have this. If not I would think you have a stuck closed relay somewhere and it may be related to your above question. Look up what relays are involved on the under side of the fuse box cover.


3. My front orange marker lights stay on with lights off / car running. But work properly when signaling.

Both sides of the car? Does your car have a USA VIN? This may be normal in other markets Porsche sells into. If not this is related to the ignition switch or the relay associated with your running lights. Since all three of your problems seem to be related to items being powered when the ignition seems to be in a off position I would test the ignition switch for proper function. Something done with a schematic and a conductivity tester on the switch pins when it is unplugged from its wiring harness. Or you could just get the switch part of the lock assembly and swap it out with a fresh one. Andy :-)

How should I begin to trouble shoot?