Why would voltage gauge peg?
05-14-2016, 06:30 AM
#1
Rennlist Member
Thread Starter
Why would voltage gauge peg?
Good morning to the 928 braintrust!
I've just gotten back into the garage on a limited basis after a hiatus and need some electrical help.
Am checking out a new-to-me 86 car.
With key in on position, voltage is 13 or so.
As I start the car, the voltmeter pegs so hard I have to slap the pod to dislodge it after shutting motor off.
Otherwise, it seems to run well.
Battery is relatively new and has been on a tender.
Does the meter maxxing-out mean that there is an alternator problem?
How should I approach the situation?
I've just gotten back into the garage on a limited basis after a hiatus and need some electrical help.
Am checking out a new-to-me 86 car.
With key in on position, voltage is 13 or so.
As I start the car, the voltmeter pegs so hard I have to slap the pod to dislodge it after shutting motor off.
Otherwise, it seems to run well.
Battery is relatively new and has been on a tender.
Does the meter maxxing-out mean that there is an alternator problem?
How should I approach the situation?
Last edited by Landseer; 05-14-2016 at 06:45 AM.
05-15-2016, 09:27 AM
#5
If the gauge is going to 13 or more volts by just turning the key on, without starting...I'd assume it's the gauge. Battery voltage should be around 11.7/12.4 at the gauge, if battery is fully charged - 12.4/12.7, when car is not an running. Reading are just a rough estimates, since wiring condition can determine voltage drop significantly.
With car running, you should see readings of about 13.6/13.8. Anything higher will contribute to prematurely failed electrical parts elsewhere.
I'd verify true voltage readings, running and not running, with a DVM. This will elimate the guessing game about voltage readings.
Good luck.
Brian.
With car running, you should see readings of about 13.6/13.8. Anything higher will contribute to prematurely failed electrical parts elsewhere.
I'd verify true voltage readings, running and not running, with a DVM. This will elimate the guessing game about voltage readings.
Good luck.
Brian.
05-16-2016, 02:02 AM
#6
Rennlist Member
Join Date: Nov 2011
Location: Adelaide, South Australia
Posts: 724
Likes: 0
Received 84 Likes
on
44 Posts
Good morning to the 928 braintrust!
I've just gotten back into the garage on a limited basis after a hiatus and need some electrical help.
Am checking out a new-to-me 86 car.
With key in on position, voltage is 13 or so.
As I start the car, the voltmeter pegs so hard I have to slap the pod to dislodge it after shutting motor off.
Otherwise, it seems to run well.
Battery is relatively new and has been on a tender.
Does the meter maxxing-out mean that there is an alternator problem?
How should I approach the situation?
I've just gotten back into the garage on a limited basis after a hiatus and need some electrical help.
Am checking out a new-to-me 86 car.
With key in on position, voltage is 13 or so.
As I start the car, the voltmeter pegs so hard I have to slap the pod to dislodge it after shutting motor off.
Otherwise, it seems to run well.
Battery is relatively new and has been on a tender.
Does the meter maxxing-out mean that there is an alternator problem?
How should I approach the situation?
Sometimes works just like Porsche wanted.
Sometimes needle never moves off the bottom, like there is no battery.
Sometimes goes full scale as soon as the key is turned and stays there.
I have a digital voltmeter plugged into the cigar lighter socket now and despite where the stock voltmeter is, the digital one sits on about 13.5-8 running and about 12.3 idle.