Odd Voltmeter

[Racinbob 11,094]

I'm planning on changing the ammeter with a voltmeter on my 854 as well as putting one on the golf cart so I picked up two of these from a place called IG Tuning down in Miami. Duck soup, right? Two posts, + and -  and the light.  The light is clearly obvious and, at least to me, the + and - is too. I'm not confident that I'm right though. I checked their website and couldn't find anything. I contacted the seller and he is on vacation until the 5th. So I figured I'd go to the best source. First, I have no clue what the little red light is for. Secondly, what are the two spade lugs for? I'm tempted to assume they are for the red light. I figured I was safe to assume that the + was the isolated one to the upper right and - was the other one. There are no markings on the case. What do you folks think? Anybody seen one similar? 

 

Edited April 3, 2021 by Racinbob

[Jeff-C175 7,202]

I'm tempted to think that the red light is an idiot light for the charging system but that's just a guess.

 

Is there any branding or model number on it?

 

Edited April 3, 2021 by Jeff-C175

[squonk 41,155]

Posts are + & -.  little spades are for   it lights up at night on your way back from the church card game. Big guy is the light that lights up if the Voltage is too low when Nancy is driving. 

Edited April 3, 2021 by squonk

[Jeff-C175 7,202]

Russian?

 

[ebinmaine 67,627]

Here's what I'm thinking the main connections are. 

 

 

 

 

Not at all sure what the 2 small spades are...

 

[Racinbob 11,094]

1 hour ago, Jeff-C175 said:

I'm tempted to think that the red light is a idiot light for the charging system but that's just a guess.

 

Is there any branding or model number on it?

 

37 minutes ago, Jeff-C175 said:

Russian?

 

 

That's the only marking on it. Russian is a good thought. 

 

43 minutes ago, squonk said:

Posts are + & -.  little spades are for   it lights up at night on your way back from the church card game. Big guy is the light that lights up if the Voltage is too low when Nancy is driving. 

 

And now, the rest of the story. (in my best Paul Harvey impersonation)   That's what I thought too Mike. I decided to see if the red light came on when there was power so I got out the gator clips and grounded the post that was common to the case and touched the post that isolated from the case. There was a fairly loud snap, I immediately disconnected it and I got to watch the inside of it fill with smoke.   Obviously I'm down to one now. That's not as bad as you might think. The description didn't say a thing about the diameter. I assumed they were 2". Nope. 2 1/4". That will be fine for the golf cart but certainly not the 854. I went ahead and ordered a 2". Then I was digging through some boxes and found a brand new 2" . I guess I need to wait to see if the seller knows and responds. 

[Racinbob 11,094]

That's what I assumed Eric. The light was a no brainer but that's the way I tried on the meter. OOPS!

I wonder if it's possible for this to be for a positive ground system. But even if it was I don't think a quick reverse polarity would instantly fry it. 

[Racinbob 11,094]

I just did a search for 3n8006-2 and there was one result.

 

=HEUD µ 'RFNLQJ )HDWXUHV 6WDWLRQ

rbs.rdsoft.ch › l › detail

86% 32576 +'0, (7+(51(7 3257 32:(5 83/< ,1387 3ruw uhsolfdwlrq)hdwxuhv 3ruw uhsrolfdwlrqv iru hwkhuqhw 5- 86% slq +'0, slq srzhu lqsxw

 

[ebinmaine 67,627]

Honestly Bob...

I won't put an unmarked gauge or ignition switch in anymore. 

 

I'd demand a refund on the grounds of defective or unusable material. 

 

[Racinbob 11,094]

It's not really worth it Eric. There's were pretty cheap on Ebay. I did leave him feedback and dinged him a little on item description. I did mention in the message that he needs to state the size. I'm sure glad I don't need to do a resume. I can see it now:

 

Years in the electrical trade:  50+

Can you install a voltmeter: Nope but I can fry them.

 

Edited April 3, 2021 by Racinbob

[Jeff-C175 7,202]

14 minutes ago, Racinbob said:

3n8006-2

 

But it's not a 3 and not an N ... you need the Cyrillic font for those!  

[stevasaurus 22,764]

I think it all made more cents, since, sense when @squonk 1st had the   + 7 -  in his post.  Now with him editing it to  + & -   it makes no cents, since, sense at all.  

   We already know it is 12.5 volts, why do we need a meter???

 

[ebinmaine 67,627]

2 hours ago, stevasaurus said:

why do we need a meter

I look at mine every single time I start the tractor. Tells me it's charging. 

[8ntruck 7,016]

5 hours ago, Racinbob said:

It's not really worth it Eric. There's were pretty cheap on Ebay. I did leave him feedback and dinged him a little on item description. I did mention in the message that he needs to state the size. I'm sure glad I don't need to do a resume. I can see it now:

 

Years in the electrical trade:  50+

Can you install a voltmeter: Nope but I can fry them.

 

You just proved my magic smoke theory - all electrical or electronic devices operate on magic smoke.  If you let the smoke out, they quit working!

[ebinmaine 67,627]

9 minutes ago, 8ntruck said:

You just proved my magic smoke theory - all electrical or electronic devices operate on magic smoke.  If you let the smoke out, they quit working!

A little known and poorly understood fact of rubber/vinyl/plastic coatings. 

They are excellent materials for holding the magic smoke in where it's supposed to be. 

[Racinbob 11,094]

I just received a reply from the seller.

 

"it's just a voltmeter, only use positive and negative."  DUH!

 

I'm pretty careful about stuff like this but after it happened I had to double check myself. I had clipped both ends of the test lead the negative to the meter post and a battery. I just clipped the positive to the meter  post and touched the other end to the battery terminal so the negative was still connected as I watch it fill with smoke (actually it looked pretty cool) Sure enough I had it connected properly. We'll see what the seller does. Usually electrical items like this aren't covered. 

[ebinmaine 67,627]

4 hours ago, Racinbob said:

Usually electrical items like this aren't covered

EVERYTHING defective is covered. 

 

If you connected correctly and it fried, you deserve a refund or replacement. Period. 

 

[Brakechute 1]

Just a WAG but I would say the two small spades are the electrical connections for the gauge.  As for the studs, did it come with any mounting hardware?  

[Racinbob 11,094]

Nope. I tried that on the unblown meter. It just brought on the red led. I can't help but think @ebinmaine is correct in post #5. The mounting bracket is a metal strap that connects to the negative (common to the case) post. Since I had nothing to lose I tried the second meter. Oops! More smoke. Tried to contact the seller again. He is now 'no longer a registered user'. 

[Jeff-C175 7,202]

@Racinbob Did you notice if when you applied the voltage the meter SLAMMED hard right full scale?

 

If so, it's likely that an external resistor needed to be used with that meter.

 

At the end of the day, a VOLT meter is an AMMETER with a SERIES RESISTANCE.

 

MOST Voltmeters have the resistance installed INTERNALLY, but some do not.

 

Too bad you fried them, I would have suggested a large resistance in series to limit current.  If you have a 'resistance decade' you could have used that to adjust the resistance and figure out what value was needed.

[Racinbob 11,094]

Nope Jeff. No movement at all. Not really even a pop. Just a very small tick and smoke filled it. It's no biggie. They were 2 5/16" which wasn't mentioned in the listing and I really didn't have a use for that size. I haven't tossed them yet so I'll open one up. Maybe I can figure out what happened.