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Changing ampmeter to a voltmeter
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Changing ampmeter to a voltmeter
I am trying to confirm wiring
I terminated the wires to the ampmeter
Ran a new wire from the on post of the ignition to the positive post on the voltmeter and a new wire from the ground to the negitive post on the voltmeter
It reads 8 volts and not 12.6
Battery test at 12.6 with a multimeter on the battery post
Shunt, voltage regulator not bothered except to terminate the old ampmeter gauge wires behind the instrument panel
Help
I terminated the wires to the ampmeter
Ran a new wire from the on post of the ignition to the positive post on the voltmeter and a new wire from the ground to the negitive post on the voltmeter
It reads 8 volts and not 12.6
Battery test at 12.6 with a multimeter on the battery post
Shunt, voltage regulator not bothered except to terminate the old ampmeter gauge wires behind the instrument panel
Help
Re: Changing ampmeter to a voltmeter
Okay so what are trying to read on the voltmeter - battery voltage or running voltage from the alternator ?
If you want to read the battery voltage then you can connect to the ignition switch as that derives from the battery. If you want to read the alternator running voltage then you cannot connect to the ignition switch but need to connect a wire from the alternator to the voltmeter. This may have been the wire that originally went to your ammeter.
The other question is why are switching in the first place ? The ammeter tells you a lot more about what is going with either current draw or charging then just seeing what the voltage is at.
Either way is looks like you are dropping voltage from the starter to the ignition switch. You need to measure the voltage going from the battery to the starter to the ignition switch to see where you are losing voltage. Maybe the start relay ?
Mark
If you want to read the battery voltage then you can connect to the ignition switch as that derives from the battery. If you want to read the alternator running voltage then you cannot connect to the ignition switch but need to connect a wire from the alternator to the voltmeter. This may have been the wire that originally went to your ammeter.
The other question is why are switching in the first place ? The ammeter tells you a lot more about what is going with either current draw or charging then just seeing what the voltage is at.
Either way is looks like you are dropping voltage from the starter to the ignition switch. You need to measure the voltage going from the battery to the starter to the ignition switch to see where you are losing voltage. Maybe the start relay ?
Mark
1953 CC Rocket Runabout "Rocket Man"
Re: Changing ampmeter to a voltmeter
Are you sure your Voltmeter is calibrated correctly? With the ignition on and the meter showing 8 volts, connect your multimeter to the voltmeter terminals to confirm the reading. If it is 12 volts then your Voltmeter is off, if it is 8 volts then you have a high resistance connection somewhere between the battery and the gauge which could be on the hot or ground sides.
BTW - When checking the voltage at the battery, put the leads on the cable clamps, not the battery posts as it is not uncommon to have a bad connection there. You should also have the ignition on so there is a load on the battery.
Denis D
BTW - When checking the voltage at the battery, put the leads on the cable clamps, not the battery posts as it is not uncommon to have a bad connection there. You should also have the ignition on so there is a load on the battery.
Denis D
Denis
1948 17' deluxe runabout
1948 17' deluxe runabout
Re: Changing ampmeter to a voltmeter
Re: Converting Ampmeter to Voltmeter
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Post Thu May 17, 2018 1:19 pm
I still have not solved this question and read only 10 volts on the voltmeter and battery reads 12.2. I have the old voltage regulator, alternator and shunt still installed. Would these items be interfering with the voltage reading?
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Post Thu May 17, 2018 1:19 pm
I still have not solved this question and read only 10 volts on the voltmeter and battery reads 12.2. I have the old voltage regulator, alternator and shunt still installed. Would these items be interfering with the voltage reading?
Re: Changing ampmeter to a voltmeter
Well if you are expecting someone to reply and say "oh a 2.2V drop is definitely the ......" you may not get it.
In the mean time I would suggest that you either remove the possible offending items that you mentioned or jumper them out one at a time and see when and if the voltage goes back up to 12.2V.
If you do that and nothing changes then you may have a bad gauge.
Mark
In the mean time I would suggest that you either remove the possible offending items that you mentioned or jumper them out one at a time and see when and if the voltage goes back up to 12.2V.
If you do that and nothing changes then you may have a bad gauge.
Mark
1953 CC Rocket Runabout "Rocket Man"
Re: Changing ampmeter to a voltmeter
Can you post the wiring diagram for your boat?
Denis
1948 17' deluxe runabout
1948 17' deluxe runabout
Re: Changing ampmeter to a voltmeter
Here is one from 1952
Jim Staib
www.finewoodboats.com
1947 Penn Yan 12' Cartopper WXH474611
1950 Chris-Craft 22' Sportsman U-22-1532
1957 Chris-Craft 26' Sea Skiff SK-26-515
1968 Century 17' Resorter FG-68-174
www.finewoodboats.com
1947 Penn Yan 12' Cartopper WXH474611
1950 Chris-Craft 22' Sportsman U-22-1532
1957 Chris-Craft 26' Sea Skiff SK-26-515
1968 Century 17' Resorter FG-68-174
Re: Changing ampmeter to a voltmeter
That doesn't appear to be the correct wiring diagram, he says he has an alternator and regulator, not a generator.
Denis
1948 17' deluxe runabout
1948 17' deluxe runabout
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