Voltage Options

[mipstien]

my idle voltage is around 13.3-13.4 and my at load votlage is around 13.5-13.7
is that anything to worry about? possibly regulator on the way out? seems just a little low. i know 13.8-14 are about where it SHOULD be but i just wanna make sure so i don't get stranded.
the voltmeter in the car just started to show around 12-13 instead of the consistant 13.5+ that it was hovering around. i know its not perfect nor 100% accurate but that concerned me after the car was good and hot it dropped the voltage which is why i checked it with a multimeter.
just a few concerns.

[Mike Bellis]

You will not get a good reading from a 35 year old electrical system. Take your readings directly from the battery terminals with a digital volt meter. Your idle speed needs to be closer to 900rpm. You should have maximum voltage above 1500 rpm.

Wire has a life span. Any corrosion will cause a voltage drop across the wiring. Even if your wiring looks good and the insulation is pliable, there is corrosion inside do to plastic being porous. You should put new battery cables on every few years even if they look OK. Beacuse Porsche installed wire sizes barely adequate for the charging system (typical industry practice) it is very difficult to get an accurate reading from any wire at the fues panel. It is normal for and old system like ours to show voltage drops on the dash gauge when turning on any accessory. Especialy turn signals.

The best thing you can do to improve your charging system is to upgrade the charging wires. Change the alternator charge wire to a number 4 copper conductor. Add a couple more ground wires from the battery negative to the chassis and from the battery negative to the engine block. Change the positive cable to the starter to a number 2 copper wire.

After this, go to every ground lug connection on the body and wire wheel the metal until its shiny. This is extreemly helpful at the headlights and near the fuse panel. Dont forget the one near the relay board. Short of rewiring your car with larger wire, these steps will really help your system.