Joe C.

I am trying to find out if there is any hidden voltmeter indicators in my 2009 997S. I would like to keep an eye on the voltage while driving, starting etc. It would be nice to find an on screen source to view it, if not does anyone have an idea or install on one of the small digital volt displays that you can purchase online and where did you install it source the voltage etc.


Thanks for any help

Joe C.,

gasongasoff

There's a ton of cigarette-lighter plugin voltmeters on Amazon for about $10. I monitor voltage using a PLX gauge installed inside my chrono wart. Many OBD readers can display voltage. Or if you have a Fluke 87 lying around...

Joe C.

Thanks for your reply, yes I'm looking for something more oem looking rather than the cigarette lighter style. Im interested in how you put a plx guage inside the wart. I'm assuming thats the sports chrono wart on top of the dash.

Bruce In Philly

Interesting...... so that is all a typical dashboard voltmeter reads? No other sophistication? Ihave limited experience with this type of guage...... so I can just toch my DC/volts selector on my Fluke to two leads coming from a cigarette light plug.... boy that is simple.

Peace
Bruce in Philly

Joe C.

While driving? I'm trying to monitor my charging system while driving like all my older porsches' had with an oem voltmeter, to see if alternator is charging properly

ADias

IIRC only the 996 had a voltmeter. All 911s up to the 993 did not have one from factory either. I see no reason to monitor voltage in real time as the charging light is enough to monitor charging. Should the charging light flicker or turn on, then that's time for proper analog voltage monitoring, using a full-fledged multimeter or a plug-in voltmeter (I like the Innova unit).

Wayne Smith

I like live voltage readings. My red green color blindness makes the idiot light invisible, unless it's dark outside.

I got stuck in the middle of nowhere driving cross country in a Ryder truck when I didn't realize the alternator had failed.

The alternator failed on my F250 a couple of years ago. I didn't see the idiot light but I did see the diminishing volts. With 200 miles to home I kept the accessories off and made it with 9 volts left.

Give me a gauge. You can keep the idiot lights.

Joe C.

Yes I too prefer live readings and gauges. My son's 996 was spiking up to 16 volts as he pulled into my driveway he also noted that the higher rpms spiked the voltage. I felt it was the voltage regulator. The next morning the battery was dead with zero volts. Since it was only 2 years old I revived the battery with a battery charger replaced the regulator and all is well now. I will always prefer gauges to lights.

NOW about my oil level stick or lack of one that's another story

thanks Joe c.

ADias

Of course a voltmeter is better. I posted a reply due to the OP's statement: "like all my older porsches' had with an oem voltmeter." Older 911s (996s excepted) did not have OEM voltmeters, even those with alternators failing with spiking voltage levels. Ask me how I know...

My experience with failing alternators/regulators is that the more common low voltage failure is handled by the charging light (my apologies to those with color blindness). The more damaging voltage spiking due to an asymmetric rectifier bridge failure is easier to spot with a voltmeter, if you catch it quickly as those failures tend to be sudden and often catastrophic. The idiot light can also identify spikes if the circuitry behind it is designed to do so; I do not know if the modern ones do that, but I do know classic cars's (read air-cooled) charging lights do not.

I do monitor my 997 charging system periodically using the Innova plugin voltmeter and look for voltage level trends over time.

Incidentally... be careful jump-starting a battery attached to the car. Many rectifier/regulator failures due to current surges occur during that process...

P.S. - When I had a 996 its voltmeter was never useful to me. I wondered then why a voltmeter was there (when I could always use a plugin unit) instead of an oil temp gauge always present in every 911 gen until then... Trade-offs.

gasongasoff

The PLX gauge (60mm) fits right where the "clock" mechanism goes, behind the clear plastic dome. You'll need to run a cable to the OBD port, and another cable for the small remote control (i.e. to the glovebox or center console). It's definitely a project! You can choose different screens to display - the one I use has 4 different OBD readouts, one of which is voltage. Sometimes I run my car stereo with the ignition off, so this lets me know when it's time to start the car or hook up a charger. This is what it looks like in someone else's install:
https://www.6speedonline.com/forums/...lti-gauge.html

Also, there are now bluetooth OBD2 readers that you can link to your smartphone - I bet there's a way to get a live readout of voltage that way too.

ADias

Don't you think that an indirect voltage reading via the OBD2 port is prone to error? When an alternator fails (low or spike voltage) The ECU may not work correctly and provide erratic output. If one wants to know what the battery voltage is the sure way is a voltmeter connected to the battery terminals directly or through a low resistance connection.

Joe C.

Well I certainly did not want to spark a controversial argument on the pros and cons of voltage monitoring, I merely wanted to get some ideas on installing a voltage meter (preferably a digital one) in my car, I got to say however gasongasoff you got some big brass ones if you did that to your dash.

I guess I'll have to settle for the cigarette lighter plug in type for now

Thanks Joe C.

mike cap

Just as an aside the Escort radar detectors have a VDC default display selection that is nice and reads out whenever there is no radar detected. I have this set on the 993 and 997. Easy solution if you have the radar detector anyway.

Wayne Smith

Sweeet.

gasongasoff

It probably depends on your usage. I use the voltage readout in the PLX to detect when the battery charge is running low when listening to my car stereo with the ignition off. It works perfectly and has always given me a valid reading even after I've discharged battery beyond the point where it needs a jump (which I don't let happen anymore). I'm not using it to detect alternator failure, although if you get in your car, and the voltage readout is low, this suggests that the battery didn't get charged adequately during the last drive (alternator or cable issue) or the battery isn't holding a charge anymore (time for a new one) or you left the car for a couple weeks without driving it.

Oh, that was someone else who retrofitted the SC wart in a car without SC. My vehicle came with the SC wart already, so all I had to do was slap in the PLX (and run the cables, of course).