Warninglights...

[Mattias Hellore]

When I was out tonight and driving my old 911.

I shut off the car after 10 minutes of driving and my key was out of starter switch and the green and the red lights on the oil pressure/temperature gauge lighted up.

Still lighted when I was back in the car after 1 hour and I started the engine and let it run for some minutes and checking the oil level, near the max marking and pressure reads OK.

I think it´s a error in the electric system.
But the red light is for the alternator and charging circuit, the fan belt is OK.

The 911 is home in my carport and it´s not lighted up now but when I start the engine they lighted up.

The car is a 911 SC 1979 with about 100k miles in it.
In good condition and running strong, no flickering in headlights or so when the engine revs up.

Any suggestions?

[Mattias Hellore]

I was out for about 5 minutes with my girlfriend, we consulted 101 projects book and hwo we shall trobleshoot the alternator.

running 2000 rpm and reading the voltmeter.
It reads 11.8 V, with the engine off 12.1 V, I think the alternator just said good bye?.

Any suggestions?

[bell]

it could very well be a bad alternator, i would do a load test on your battery to see if it's ok first, a bad battery can burn out the diodes in an alternator in very short time.
also check your ground strap from the engine to make sure it's secure/not corroded. if these check out ok, it will most likely be a bad alternator. i haven't had problems with the alternator in my 911 but they all work the same way.
anybody else?

[RoninLB]

I can't make a correct answer from here...Bell is on the right track, follow his lead...if all the logical diagnostics still leaves you scattered I would consider the ignition sw. as a possibility...IMO, a ign. sw. that's 23 years old and 100k has one foot on a bannana peel and the other foot in the grave...If you do wind up spending $40 for the sw. and it's not the problem you just performed preventive maintance, IMO.....Ron