Topic: '40 Ford N.O.S VOLT GAUGE


sarahcecelia    -- 07-18-2017 @ 1:29 PM
 

Regards, Steve Lee

This message was edited by sarahcecelia on 7-28-17 @ 1:28 PM


kubes40    -- 07-18-2017 @ 3:49 PM
  Did you test the battery?

Mike "Kube" Kubarth


sarahcecelia    -- 07-18-2017 @ 4:38 PM
  Regarding : "Did you test the battery?" As far as volts? Yes, it was a little over 6 volts,(6.2 or so) with one of those Harbor Freight meters. It's always on a Battery Butler in the garage.If I go to a show 20 miles away, when I want to leave the battery is "up" and cranks her right up. I never have "Battery trouble" Of course, she always starts like all good flatheads do-instantly!!If she sits in my garage for a few days, sometimes she starts and stalls, Then I give it a little choke, and she starts again pretty quickly.

Regards, Steve Lee

This message was edited by sarahcecelia on 7-18-17 @ 5:08 PM


sarahcecelia    -- 07-18-2017 @ 4:54 PM
  "Kubes,"I suspect the gauge, but want to know if you think it is. Can I test the new gauge in the manner I stated? You and I both know that gauge is 77 years old, but have you heard of them going bad? I would think so, but really don't know. It looks awfully tight to get to that old gauge, and why woud I change it only to find out it's not the problem,.That's why I'm "trouble shooting" to try to find just what the problem is; Thus- test the new gauge with jumper wires first. Again, can I do that with a jumper from one terminal on the new gauge,to the BATT on the regulator, and a jumper on the other new gauge terminal, to the positive terminal on the battery? I think so? And you?

Regards, Steve Lee


kubes40    -- 07-18-2017 @ 5:50 PM
  Steve, Like you, I troubleshoot prior to simply replacing parts. Kind of a "lost art" as it seems most folks just start replacing parts until whatever is malfunctioning - works.
I am hoping TomO jumps in here and advises you how to properly test the gauge. He's taught me a lot about electrical stuff but I still defer to him.

So, TomO, where are ya???

Mike "Kube" Kubarth


TomO    -- 07-20-2017 @ 9:37 AM
  The battery gauge is a volt meter so you can test it by connecting it between the BAT terminal on the voltage regulator and ground.

The dash gauge does not care how many amps that your generator is putting out, only the voltage. The gauge is slow acting, so be patient.

You never stated what voltage you are reading at the BAT terminal of the voltage regulator when you raise the RPMs to 1200 RPM. This is important, as a weak battery or one that is not fully charged will affect the gauge reading.

Here is a link to your post where you were given what the gauge should read for

https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=18&Topic=10914&keywords=gauge

The voltage readings should be taken at the dash gauge and could vary as much as 0.2V from the voltage regulator readings.

Tom


sarahcecelia    -- 07-21-2017 @ 7:24 PM
  Tom O what do you have to say???

Regards, Steve Lee


sarahcecelia    -- 07-22-2017 @ 6:01 AM
  Tom,
I just had the generator rebuilt, ( new brushes and clean commutator) and regulator replaced, and the guy who did it is well up in age, did that stuff for years with (4) employees, now semi-retired.
He showed me the readings as he ran the generator, and new regulator, with me present, and all of his gauges running . All were good readings.
My battery reads about 6.2 or 6.4volts, w/o the motor running.
I'll connect the NOS gauge w/jumpers, to BATT on the regulator, and other terminal to ground, and run motor at 12-1500RPMS and see what it reads.

Regards, Steve Lee


TomO    -- 07-22-2017 @ 7:35 AM
  Steve, the voltage and current readings on the test setup have no bearing on the reading of the dash gauge. The only voltage check that has a bearing on the accuracy of the dash gauge is the one taken at the gauge posts.

It is much more difficult to get under the dash to connect a voltmeter to the dash gauge, so the first step is to measure the voltage at the voltage regulator. If that shows the dash gauge reading is inaccurate, the next step is to measure the voltage at the dash gauge or do a voltage drop test to determine if there is excessive voltage loss between the battery and the dash gauge.

The readings shown on the dash unit are never exact as you just have color bands to show the voltage. The dash gauge is there to alert you to signs of trouble. If the needle is in the red at the right side of the gauge, it means stop the engine right now, before you damage the generator. If it reads in the red at the left side of the gauge, your charging system is not working and your battery is discharging. The orange section means that the battery is fully charged, but the charging system is not keeping up with the battery drain. The green section means that the charging system is keeping uo with the drain.

My dash unit will read just into the green when the car is at road speeds and the battery needs some charging. When the battery is fully charged, it will read at the left edge of the green band. With the lights on, it will move back into the green band and with the lights and radio on, it will be at the left edge of the orange band.

The dash gauge is not an instant reading unit, like an ammeter, it takes approximately 1 minute to reach equilibrium.

When you have read this post carefully, spend some time digesting he information and then read it again and make a list of how to connect your voltmeter to test the dash unit. Then goi back and read the post again to see if you are doing it correctly.

Tom


sarahcecelia    -- 07-23-2017 @ 7:49 AM
  Mike" Kubes", Where should the 1940 voltage gauge needle be when power is off? Mine is about 1 eighth of an inch below the first red area. There is an adjustment area on the back, so maybe I need to adjust it if the volts are right at the regulator "Batt" Terminal. 7.2-7.4 @12-1500 rpm's.

Regards, Steve Lee


sarahcecelia    -- 07-23-2017 @ 3:30 PM
  With my El Cheapo meter it jumps all over. (Actually "bounces" back and forth rapidly.It doesn't do that on any other test I have done, like battery voltage etc. Weird, huh??

Regards, Steve Lee


sarahcecelia    -- 07-24-2017 @ 1:39 PM
  Mike "Kubes" Kubarth,
I sent you a PM yesterday, Sunday the 23rd of July. Did you get it?
It was about how my old gauge was wired, and the fact the it was "hot'ed" to the ground strap.I need a reply please.

Regards, Steve Lee


sarahcecelia    -- 07-24-2017 @ 7:44 PM
  Tom, I have some wiring on the oil + volt gauges in this car that I don't understand. There was a strap between the oil and volt gauges, passenger side, and the post on the voltmeter (w/the strap on it,) had (2) grn./ blk. wires connected to it.The other side of the voltmeter had nothing on it. "Kubes" said that strap was a ground, but It looks like it provides power to oil and volts gauges, and the case of the volt gauge was providing ground. The other terminal which had nothing on it, should have a ground wire on it? The right side terminal on volts, is insulated w/cardboard, so that to me should be power side. What's the story? Would it be possible to call me to get this straightened out? It seems to take a lot of typing to+fro to sort all this out, where one phone call could do it. 352. 666 .9916 Florida

Regards, Steve Lee


TomO    -- 07-25-2017 @ 6:56 AM
  Here is a copy of the wiring diagram from the shop notes. Your gauges should be wired as shown.

Tom


kubes40    -- 07-25-2017 @ 9:52 AM
  Steve, I may have been mistaken about the purpose of that strap and if so, I apologize. I've done so many of the '39 - '40 Fords, I rarely even think about, much less look at a schematic.
I have to tell ya, TomO in my opinion has this electrical stuff down to a science. I'd not hesitate to listen carefully to any advice he may offer.

Mike "Kube" Kubarth


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