normal voltmeter readings

[sids]

just slapped one on last night and upon startup voltage was steady at 14v - 13.8v, put it into drive (car is an auto GST) adn it goes down to 13.5, stepping on the brake while traffic while the car is in drve and it sometimes dips down to 11.5-11.7, put it in nuetral (RPM is abit higher than when in D) and it goes to 12.7-13.5.

Now it ain;t stumbling, gurgling or anything but is volatge going down to 11.5 normal?

I tapped the cig lighter power source for mine, I think this reads the voltage straight fromt the alternator and is sort of RPM dependent because products like G Tech plug intot he cig lighter to read engine RPMs

 

[HSK]

where did you get one? i think i should try testing my car.

just slapped one on last night and upon startup voltage was steady at 14v - 13.8v, put it into drive (car is an auto GST) adn it goes down to 13.5, stepping on the brake while traffic while the car is in drve and it sometimes dips down to 11.5-11.7, put it in nuetral (RPM is abit higher than when in D) and it goes to 12.7-13.5.

Now it ain;t stumbling, gurgling or anything but is volatge going down to 11.5 normal?

I tapped the cig lighter power source for mine, I think this reads the voltage straight fromt the alternator and is sort of RPM dependent because products like G Tech plug intot he cig lighter to read engine RPMs

 

[LaserDad91]

To get an accurate voltage reading, you should be connected to the battery, or as close as possible to the battery. The cig lighter is an accessory, and may not give you an accurate reading, since it is going through all of the cars electrical harness and fuse block. Of course many cars come with volt meters in the dash, and I would assume they are tapping off the ignition side of the key switch, since this would be the most direct route to the battery. You will always see if you trace your connections from your alternator, one will go direct to the battery.

Yes you are correct that the voltage produced is RPM dependant, since the alternator has to spin to produce the current to charge your battery.

Typically, voltage should be around 13 – 15, with all accessories on. A fully charged battery may read 12.5 to 13 volts, depending on the accuracy of the meter. If you’re having charging problems, do this.

1. Connect voltmeter to the battery with the car off and all accessories and lights off. Record the reading; this would be your baseline.

2. Start the car, note whether the reading has changed. It should increase slightly, or remain about the same. It should not decrease, this would indicate no charging taking place.

3. If reading is lower, rev engine a little, sometimes this activates the charging system on some cars, like VW’s. If reading is still lower than step one, then system may not be charging.

4. Turn on all accessories, lights, AC, Fan, radio. Note the reading, it should be higher than step two, but not over the 15 max or so. If reading continues to decrease, alternator is not charging.

Another very handy tool, in an “inductance ammeter” gauge. This gauge will pick up the current produced by the alternator, simply by laying the “pickup” on the wire. You don’t have to disconnect any wiring to read current. Read the instructions, very handy.

I am sure an auto part store would have the gauges described above. NAPA would probably be more likely to have the ameter gauge I am refering too. Sears may have them too.

Good luck!!

 

[sids]

thanks a bunch laserdad

Well I guess I wired it correctly if I want to monitor alternator voltage readout since I've had 2 alternator failures already wherin the alternator stopped charging the battery while running. my battery's baseline is around 11.9-11.8 which is just about right, so i suppose that as lng as the voltage doesn't drop below 11.5 I should be fine

 

[eclipsefwd]

If you battery is only reading 11.9 volts it may be bad. A fully charged good battery should read 12.6 - 12.7 volts. That is with the car turned off.

 

[sids]

upon strating its 14.0 - 13.8 volts and it maintains that at idle, it only drops down to 11.9 when the shifter is in D and the car is not running, I figure this must be because the the rpms aer lower when its in gear.