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I'll try to answer oldcarbums questions from a couple posts up.
no, it is not possible to read amps through a volt gauge or the other way around. You can only read voltage levels with a volt gauge and amperage draw or gain with a amp meter.
A voltage gauge just gives you a much clearer picture of what is going on.
Example, last weekend when my Alternator dropped a diode. With my volt gauge I instantly knew it. And being a seasoned mechanic I was pretty certain it dropped a diode while I was driving down the road.
If I had a amperage gauge, my needle would have been sitting right about in the middle as my alternator was still keeping up. So I would have thought "oh yes the battery is charged up and everything looks fine."
With a voltage gauge you get a much clearer picture of what is going on.
My 77 came with a volt gauge.
The alternator actually senses voltage, not amperage.
Just because your car came factory with a amp gauge doesn't mean the voltage regulator in your alternator suddenly became a amperage regulator.
Many people convert over to a volt gauge on the earlier cars just because amp gauges really are not very useful.
I suggest you check out "Mad electricals" web site. On the top of there home page you will see a tab for there electrical tech pages. They have a couple well written, easy for us normal guys to understand articles about how all of this works. Really worth your time to have a read.
Thanks!
I learned something.
I will check Mad electronics web site.
This is the best description of voltage I could find
Potential difference is the difference in the amount of energy that charge carriers have between two points in a circuit. **Measured in Volts: **Potential difference (p.d.) is measured in volts (V) and is also called voltage.
Amperage is the measure of current flow and the amount is dependent on voltage and resistance.
As far as I know C-3's until 77 used an amp gauge feed by a shunt which is much less dangerous than having 10 or 12 gauge wire in the cabin with the full load of the electrical system. Normally an amp gauge is wired into the system. A volt gauge merely measures the voltage from the hot wire to ground
Quite off subject, a 1 wire alternator is easier to wire but takes a certain amount of rpm to excite the voltage regulator to begin allowing voltage to resupply the battery. In other words they usually don't charge at idle. A 3wire alternator is wired to charge as long as the engine is running.
Here is a photo of the wiring for a Volt gauge in a 77 Corvette.
Please see that the volt gauge is fed off off the same 18 gauge wire that also supplies power to the oil pressure guage, the temp gauge, the fuel gauge and the low fuel light. Also note this is from a Genuine G.M. manual.
Absolutely no large gauge wires here, nor needed. The volt gauge merely measures it does not consume other than a very tiny amount to move the needle
I am firmly disputing the safety claim and claim of some heavy wire in the passenger compartment claim above. ( Although there ARE other heavy gauge wires in the inside of the car totally unrelated to the gauges).
Further more, I have had 2 different 1 wire alternators in this car over several years. And while they do have there limitations, charging at idle is not one of them. Yes it is true they need RPM to activate. But idle RPM is more than sufficient.
I would suggest that ntfday would also do some reading on the subject.
It makes no difference to me what you run in your car and for qualifications I graduated as a Ground Radar Repairman after most of a year in electronics school in the United States Marine Corps in 1962.
They sure like mine, a year ago I tried to roll it outside = wouldn't move because all of the rotors were covered with
their little homes/hatcheries. Then last week I saw all of this under the air cleaner.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
had all the pistons and rods installed...Went to fit the cam and the number 4 bearing is too small. After removing it the numbers are correct...I bought 2 sets of Clevites and both sets have issues....dont buy Clevites
I took the LS6 out of the back of my truck, and placed it in the garage between the two C3s, and next to an LM7. Now to figure out which car gets which engine.
I think this is time and money well spent! Anything to improve the frame rigidity is a plus.
I’ll be doing the frame welds, adding a 4 point roll bar, using solid motor mounts, adding a spreader bar, and some of the other things called out in the Chevy Power Book.
I don’t plan to race it, but I think it should be a fun drive.
I considered going to solid motor mounts, but my engine builder strongly recommended against it. The headers are so close to everything, I didn't want to have the engine moving around much. So I went with poly mounts.
Regarding poly bushings, I wish that I stayed with new rubber instead of changing everything to poly. I did not build my car for racing. I think rubber is better for a strong "Cruiser".
I considered going to solid motor mounts, but my engine builder strongly recommended against it. The headers are so close to everything, I didn't want to have the engine moving around much. So I went with poly mounts.
Regarding poly bushings, I wish that I stayed with new rubber instead of changing everything to poly. I did not build my car for racing. I think rubber is better for a strong "Cruiser".
John
I plan to go rubber everywhere.
My Van Steel trailing arms came with poly and I am considering swapping those out for rubber even though they advised to keep the poly.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
yesterday I discovered Clevite bearings are made for ****, got those replaced with Total Seal, Got the cam in timiung gear in and heads on....baby steps
I wish you were my neighbor...I would pay you to teach me how to paint
I never wanted to learn body but after my paint guy backed out I took matters into my own hands. Couple hundred hours reading, watching videos, and forums like this one and boom; I graduated.
Changed the broken tach cable by removing the steering column and air conditioning duct. Took advantage of the time to paint the column shaft black and the tilt mechanism dark saddle.
listen to the guys who say never just change the inside cable.
02-17-2023, 08:34 PM
