Lighter-socket voltage: I want to install a cam and CAN'T due to low volts~

[Normy]

Today, I went to install a dash-cam that I bought on eBay. I installed it three weeks ago, but it didn't work. I returned it to the eBayer selling the item "wardntx", and he very promptly returned my email and told me it worked perfect for him. It still doesn't work for me: When I push the brake pedal, it causes the electrical system to lose voltage, and the cam restarts. Since it takes 45-60 seconds to reboot, this is a problem.

Hmm. That makes me think the problem might not be with the camera, it might be with the car. The only interface with the car is the 12 volts through the lighter. I got the cam back yesterday, and it worked. Until I pressed the brake pedal-

I checked the voltage at the lighter socket with my voltmeter: It is WAY low! I suspect that the connections to the lighter socket simply cannot handle the amperage. Which is beyond stupid- the lighter is a resistance heater, and it must have a huge wire [it does] and a big fuse.

WHY would voltage drop so low when you hit the brake lights? Also, when the parking lights come on, the voltage drops.

-Here's the thing: I tested the the voltage at the battery and it DIDN'T CHANGE when I turned on the lights, including the brake lights.. What's more, it was 13.4 volts, exactly perfect. System voltage is fine.

I guess the wires to the lighter socket are too small. That means that they can't handle the amperage, and as a result, voltage decreases. Which is a bit puzzling, since a dash-cam uses the power of maybe two dashboard light-bulbs, and this is way less than what the brake lights use. I'm running my stereo off of the same system, but it isn't any sort of high-power setup. I have a 40 watt head from Pioneer that also powers an iPod bus and and iPod. I cannot believe that these two actually eat up so much power that a 115 amp alternator has trouble maintaining 13.4 volts when all the lights are turned off, and only the brake lights flash.

I'm missing something~

I obviously need to rewire the dash cam. It can't work with this cigarette lighter interface, and I didn't want it that way anyway. I want to wire it into the electrical system, and put the wires behind the "A" pillar leather, and the roof, and run them behind the dashboard so that it isn't visible. I'm still working on the placement of the camera, which is too big and is silver, something I mean to change via flat-black paint.

What is a good source of power for an accessory such as this? In 1996, I drove a '92 VW Corrado SLC, and I had my radar detector powered off of the center light. I wired it into the light, and simply put the black wire to ground. I had to turn it on each time, but it would shut off automatically each time I turned off the ignition.

What's going on?

Any ideas?

N!

[dr bob]

N!--

Check the ground wire resistance WYAIT. That's a favorite thing to get dislodged when working in that area. Might be real simple.

Otherwise, there is power at the top of the CE panel. Add a fuse and a dedicated socket for the camera. Or put a utility socket in the rear tool area, good fro running that tire compressor or running the battery maintainer. Fused feed direct to battery terms from back there.

[XLR8928]

Run a dedicated wire to your fuse box, going to a dedicated connector. I never experienced the electrical weirdness on my other German cars that I've seen on my 928. I think Porsche may have hired an ex- Lucas engineer to design the electrical systems on the early cars.
-Kerry

[harborman]

The lighter socket may have a lot of corrosion. Your cam should not draw anywhere near what a lighter draws. To check, hook the cam up to the battery directly with an amp meter and see what it draws. Check your main ground and other ground connections. Check fuse for lighter and it's contacts. If the rest of the car is working, you have some kind of bad connection for the lighter. Does the lighter work??? The cam may draw so little current, with any slight resistance you may get pretty good voltage drop.

[MPDano]

I never actaully ran a voltage checker on my ciggy lighter, but I do remember plugging in my Phone Charger there and it doing weird things. I would also agree with the others and just run a dedicated one with a fuse on it. Also, running a straight run from the battery isn't hard either.

[harborman]

"I checked the voltage at the lighter socket with my voltmeter: It is WAY low!"

Check the voltage at the fuse for the lighter. A volt meter puts virtually no load on the circuit. Scrape the center contact and clean up the sides of socket if you can. I would start at the fuse or link. Or run a new line as one member suggested. When making voltage checks, make sure you are getting a good connection with the meter. Test that hot lead to another ground point you know is good with the meter.

[tisilrad]

i agree that you should run a dedicated line for this, tapping into the fuse box for power. There are several factory vehicles out there with a dedicated power port that you could scavenge from the local junkyard for very little(or no) money, they will have plugs to keep the port covered when not in use and labels on said plugs...if you can access the salvage yard yourself look for family hauler vehicles..in the back seat areas...these have properly sized wiring etc as well...

[Normy]

Where is a good place on the fuse box to tap into for power? I think I'm going to just use an inline fuse from Radio Shack, so I need a convenient tap in point.

N

[Normy]

Originally Posted by tisilrad

i agree that you should run a dedicated line for this, tapping into the fuse box for power. There are several factory vehicles out there with a dedicated power port that you could scavenge from the local junkyard for very little(or no) money, they will have plugs to keep the port covered when not in use and labels on said plugs...if you can access the salvage yard yourself look for family hauler vehicles..in the back seat areas...these have properly sized wiring etc as well...

-That's not a bad idea at all, a good WYAIT thing. An extra 12 volt lighter plug mounted to the passenger-side tray might come in handy some time. Good idea!

N

[harborman]

Originally Posted by Normy

-That's not a bad idea at all, a good WYAIT thing. An extra 12 volt lighter plug mounted to the passenger-side tray might come in handy some time. Good idea!

N

Does the lighter work?? I would still want to know why it is not supplying voltage. I think the fewer holes or modifications made to dash is better. Keep it as stock as possible unless you can mount the additional plug out of sight.

[MPDano]

Originally Posted by harborman

Does the lighter work?? I would still want to know why it is not supplying voltage. I think the fewer holes or modifications made to dash is better. Keep it as stock as possible unless you can mount the additional plug out of sight.

For this, he wouldn't need to make holes anywhere. If your unsure where to tap on the CE Panel, then don't take any chances, just run a fused line from your battery. It's a pretty short run, it's not like your running a wire to the taillights on a station wagon or something

As far as his lighter, I am sure if he traced the line from end to end, he'll find bad contact somewhere.

[harborman]

Originally Posted by MPDano

For this, he wouldn't need to make holes anywhere. If your unsure where to tap on the CE Panel, then don't take any chances, just run a fused line from your battery. It's a pretty short run, it's not like your running a wire to the taillights on a station wagon or something

As far as his lighter, I am sure if he traced the line from end to end, he'll find bad contact somewhere.

Wonder if he fixed the problem and what he did to resolve it?