VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt Ammeter Readings

Hawkeye,

Thanks for continuing to share details about your wiring. The wiring for the under-hood light sure makes sense.

I'm still a little confused about the wiring to the starter switch. The wiring diagrams I have checked show an 8 gauge black wire going to the starter switch from the solenoid, not a natural with black tracer. I agree that there is also an 8 gauge natural wire with red tracer connected to the starter switch. That wire is connected to the battery terminal on the solenoid. The 10 gauge natural wire with red tracer that goes to the ammeter is connected to that 8 gauge wire.

I am still trying to determine the third wire (natural with back tracer) on the one post of your ammeter.

What color wires are connected to the terminal on the starter solenoid?

Like you said, it is confusing to me for sure.

Attached is a photo of where I currently am and I believe the wires are correct. If you look closely, you can see a + on the speedometer housing. I wish I had see that sooner. Anyway, to answer an earlier question. Both wires coming from the solenoid are natural with red tracers. Y n Z either look creative license or did not want to go get a new supply of the correct color wire. The red tape on one of the wires is my version of a natural wire with a very big tracer. Tomorrow, I will put back everything that I have to remove just to get to this special place. Will update you when I can.

I imagine you are ready to finish this puzzle and enjoy your pride and joy. Really nice work and outcome.

Would you please answer this one question inquiring minds want to know. The nat. with black wire you added the red tape to, what number or letter is on that wire AND what did the instruction sheet say about that number/letter?

Sorry it took this long to reply, but I had to upgrade my old computer with a new one. It took way too long to transfer all of my photos from one computer to the other. Anyway, to answer your question about the wire with the red tape on it, that is wire #19 and it goes from the + side of the ammeter to one side of the starter button. The wiring instructions do not show that, there was a tag hanging from this wire instructing where it goes. I did separate the two wires per a phone conversation with YnZ, but I didn't' have to do this. I added a terminal and that's why it looks that way.





After looking at the finished product and reviewing the instructions, I am now wondering why I did some of these connections. I don't have the telephone conversations written down to back up my work. For example, why is the black wire with yellow tracers going from the battery side of the junction block to the headlight switch instead of the( - )side of the ammeter?







I started up the car and ran it for about 5 minutes but the ammeter still shows discharging. Does this take some running time to self correct?

Thank you for the follow-up. Odd that they put that jumper on the #19 over to the start button when it is not shown in the '50 diagram. However it is shown just like that on a '51 diagram.

I have been having a hard time understanding the '50 diagram because I do not see the junction block as you have. It does not show a block with a Batt side or a switch side and what wires go to or leave from each. At least that I can understand.

The black w/yellow it picking up power from the light switch instead of the ammeter to feed something? Don't think it makes any difference.

With the motor running and you increase the rpm to say 1500 or so, does the needle move towards the C (charge) side?

Sorry that I cannot be more help at this point. I know this is painful especially now that the tracer numbers are removed.

I suggest that you need to print out the factory wrong diagram and start doing a wire to wire comparison to what YNZ sent you.

Like Russell, I am not able to locate the junction blocks you show in your pictures in the wiring diagram that is in the manual. Also, you should have the power wire to the horn relay on the + ammeter terminal. You could damage the ammeter sending all the horn current through it.

The #4 red tracer wire from the horn relay is connected to the (+) side of the ammeter per GM's wiring diagram & YnZ's.





Also attached is a photo of the instruction sheet from the GM Wiring Block. Because this was an accessory, the dealer installed it and probably did not show up on the general wiring diagram.

Thanks for the picture in your latest post that has the wires numbered. If I am interpreting that correctly I think I see some problems. Basically you a have the ammeter wired backwards.

Wire #3 should be on the - post of the ammeter. That is from the battery terminal on the regulator. That is the power coming from the generator to recharge the battery through the ammeter.

The wire with the red tape (#19) should be on the + post of the ammeter. It should be coming from the large post on the starter solenoid. It should not be coming from the starter switch. It really connects back the battery.

Wire #4 should be on the + post of the ammeter. That really just uses the + post on the ammeter as a way to jumper from the battery to the horn relay. That way the power to blow the horn does not go through the ammeter.

I am still confused about the wire #20 situation if wire #19 is really from the starter switch. If #19 is from the large post on the solenoid then #20 should be on the + post of the ammeter. That connection uses the + post as jumper between #19 and #20 to get power to the starter switch. That way the ammeter does not measure the power drain to close the starter solenoid.

Rusty, I think I need some clarification. The ammeter has BAT on the back side which I assume means POSITIVE in the 6 volts sense. The (+) on the speedometer housing reflects the face of the ammeter and means the system is CHARGING. If this is correct, then the #3 red & black tracer wire coming from the voltage regulator is in the correct position - on the BAT side (POSITIVE) of the ammeter. I need to go thru this problem one wire at a time so the other suggestions you made will be looked at later.

I believe you made a mistake with your labeling in the picture. That #20 is #19 as shown in another picture above. What you have as #19 is merely a jumper to the start switch as you described above as having a tag on it. Right?

Now, erase that "+" mark! Mark the letters BAT if that is what you see! You have already changed the wires to the new marking you discovered. Done!

Fully charge the battery. Now do the test recommended by Bloo. Don't start the car! Turn on the lights! What does the amp gage do? Does it point to D or C????? If it points to D as it should, done. If not, then their is a problem somewhere! DO THIS TEST, PLEASE.

Now start the car, rev up to 1500/1800 or so. Does the gage show towards the D, stay in the middle, or towards the C. Make sure nothing is on, including the interior light.

I don't mean to be disrespectful in any way. I want this resolved nearly as bad as you.

I did turn on the lights with the door closed and the ammeter did read discharge. (See my post back on 8/15). Then I did start the car and run it at a higher PRM and the ammeter reads "D". The (+) above the ammeter is stamped into the metal assembly so I cannot remove it. After climbing under my dash for the ### time, I took more photos and determined that I did label the photo incorrectly. Here is the corrected labeled photo.






If you look very close, you can almost see the BAT in this photo. The camera is not as good as the human eye.

THANK YOU!!

So the BAT stud is the stud under the + mark, good to know. I am of the belief you now have ALL the wiring done correctly as per the YnZ instructions.

What now?

Guess you need to find out if you are getting voltage (and how much) out of the generator and through the voltage regulator to that #3 wire to the amp gage?

Here is a really crazy idea to consider.. Maybe the generator is not producing enough current. Have you had it tested?

Sorry if that was in an earlier post.

The wire from the Bat terminal on the regulator should connect to the Bat terminal on the ammeter. I do not know how that aligns with the +/- on the housing.

NO! The BAT stud on the ammeter is behind the (-) discharge. If you are sitting in the drivers seat, it would be on the left side of the ammeter. THAT"S why the (+) on the metal housing is so confusing. That (+) must indicate the location of the charging side of the ammeter and nothing for voltage.

LOOK AGAIN, if that is the case, it is now wired backwards and you had it right the first time. #3 goes to the BAT post wherever it is.


Early you said the above. Right side from the front or back? Gage upside down or right side up. Look again.


You have a voltage issue.

Attached is a photo labeled with all the information regarding the wires on the ammeter. Also attached is a Chevrolet Wiring Diagram for 1950. The only wire on the (-) NEG side of the ammeter is the #3 red & black tracer wire going to the BAT side of the voltage regulator. The rest of the wires are attached to the (+) POS (BAT) side of the ammeter. I am assuming that the BAT terminal on the ammeter is (+) POS. Am I still missing something???


1950 Chevrolet Wiring Diagram

Post a picture of your old amp gage. Set it upright on something. Take a shot from the front and move around and a shot from the back! Trace over the BAT letters so that it shows in the shot. Don't get too close. Make sure the whole gage can be seen.

I can't find my tripod so these photos are a little blurred. Here you go.

Well my final verdict is in. The YnZ instruction sheet reads to hook #3 wire from the reg. to - on the ammeter for a very good reason. The stub on the - side IS the battery connection side as indicated in your photo of your gage. With ALL this evidence before me I have to vote that your ORIGNAL hookup was correct. Looking from the backside the #3 should be on the right stud all by itself. ALL other wires #4, #19 and the #19 jumper to start button should be on the left stud. Just as you had it in your very first photo at the start of this thread.

All the above is with the assumption that the replacement ammeter is identical to the original.

In conclusion, my thinking leads me to believe you have a voltage issue. I would do as I indicated before, to check the gen. and reg. to see that they are working correctly and what voltage is leaving the reg. in that #3 wire at above idle rpm.

Sorry you had to go through all of this, but is seems to be part of the "old car game", speaking from my own experience. Good luck!

I agree with the thinking that there is not enough current being produced by the generator. Even if the ammeter is connected backwards but properly wired the needle should move to the other side of neutral if there was enough current output from the generator.

Measure the voltage 3 places with the engine running at about 1000 rpm. Measure where the armature wire connects to the generator, measure at the Bat terminal on the regulator, and measure at the battery.

Let us know those readings.

Thinking long, think wrong. Started to second guess myself then I came across this post.
https://www.chevytalk.org/fusionbb/showtopic.php?tid/335536/
So just maybe I am right. Time will tell.

The wires are where they are supposed to be. The mistake I made was thinking that the ammeter is like a volt meter - it is not. Anyway, I did the testing that was suggested and here is what I came up with. Because my Volt Meter is part of my Dwell & Tack Meter, I had to guess at what 1000 rpm's was. Different connections are involved. At the battery, the reading was 7 volts. At the voltage regulator, the reading was 7 volts. At the generator, the reading was between 6 & 7 volts. Attached is a photo of where the wires are currently at. Thanks to everyone who added their two cents, their working experience & general interest in trying to help me solve this problem. Something that I had not noticed until taking this photo was the - marking just above the red & black tracer wire on the right. I had see the + on the left but because the wires were in the way - surprise.

So now we have come full circle. Back to the beginning of this thread. It started with:
When I look closely at the top pic where you say the needle is just touching the edge of the - mark.

Looking at the second pic you said the needle has clearly moved toward the + somewhat. Did you mislabel the two pics.

You say, when stopped the needle moves to the middle. Is this a problem?

I honestly do not know. Doesn't seem right to me. When you were checking the voltage as you described above, did you happen to notice where the needle was? You indicated you have 6/7 volts in the system so I would think it would be centered or slightly to the charge side from starting the motor if the voltage regulator is working correctly.

Just drive and enjoy for a while but keep a eye on everything. Good luck!