Last fall we added a second 7.3 to the family which became my wife's daily driver. I decided to purchase some cheap electronic volt meters that plugs into the cigarette lighter socket to monitor the battery and charging system.

What I like about these meters is that my wife doesn't have to know anything about vehicle electrical systems to know when something is wrong. I explained to her that the light should be green before she turns the key on, then it will be in the red while the glow plugs are warming, yellow when the engine starts (glow plugs still on...) and finally green again when the GPs turn off and/or the system is charged up again.

So, last Friday she told me that the engine seems to be cranking slower and it's been taking a lot longer for the meter to go back to green once the engine is started. I checked it out on Sunday and sure enough, the meter was yellow and then showed only 10.5 volts with key on. Amazingly the engine started but it sure was slow to crank so I had the batteries load tested and one was bad and the other was weak. The date code on her batteries was May of 2006 so they lasted for a good while. The brand was one that I've never heard of before (Centennial)?

At any rate, a new pair of Interstate batteries from Costco and everything is good for a few more years. I am glad I had the meter and my wife was attentive enough to notice something was wrong because it was only a matter of time before she would have been stranded somewhere needing a jump start. From time to time I travel so with my luck it would have happened while I was out of town to boot....

Here are some photos of the meter that I use and what the readings are during the various conditions. If I remember correctly, these photos were taken during a cold start with ambient temps around 30-40 degrees.

 

Pretty cool. I've always wondered how accurate those puppies were.

Like you said, it probably saved you're wife from being stranded.

Stewart

 

The one I got for $20 at walmart has always matched both AE and my scan guage on voltage readings. If it's as accurate as those two items, I don't think you could do any better.

 

Volt gauge is a good one to have.

My wife uses the scan gauge for that function quite often.

 

my dumb *** went and bought a gauge

 

OK I have read your post, now the question....where could I find one of those?

 

This is the one I got for like 3 bucks at harbor freight, I was having starting problems and was there for something else, they didn't have a digital readout one so I got one that they had, it has 6 leds on it. 3 for battery red yellow green and 3 for alternator. It did read correct when I checked it later against my Fluke meter.

12 Volt Battery/Alternator Tester

 

I told my father to get one of those for his Cummins and it's proven itself very useful. I too purchased a gauge, but I SCORED a cool old ISSPRO for less than $20 NIB! It has a zone for cranking also. I think it's my favorite gauge!

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How did you get your wife to actually watch a meter? Mine called me once and said her car was making a horrible banging sound when she turned left or right, I was working in Russia ^so I asked her to check the oil not drive it untill it was figured out! The next evening she informed me it must be the tires because the oil level gauge was right in the middle! and it's making the noise all the time now!
Jim & fat Monty

 

You ever get rid of that let me know, I am building a "picture box" of old gauges and stuff, that would be slick in it!!!

I am so glad my wife is a borderline motor head... She can change a turbo, change an alt, changes her own oil...

I never get calls like that...

 

Me Likey. Me go Harbor Freight today.

 

The ones at Wally World have the colors And the Digital Readings. By watching the Digital reading your can tell the moment you GPR shuts off and at what voltage and see how fast that it comes up to full charging of the Altenator. By Having the Digital Readings you can tell when the Altenator is charging Full (14.5) or slowly loosing its max chargeability (going down to around 13.9). With the voltage at 13.9 everything will run 'Fine'..... But you will know Waaaaay ahead of time that you Do Have Some issues 'somewhere' that need looked at..... Alt, Batts, Corrosion..... you now know that you have a 'problem' coming down the line.... to find and fix before you are stranded.

ie. Get the Color AND Digital plug in one.

 

Brother Les, do you have a link to the one at Wally world?

 

VECTOR 12-24 VOLT DIGITAL VOLTAGE METER BATTERY TESTER | eBay

 

Have no link. I just walked into the auto section and found a bunch hanging on a rack. It looks like the ones on this thread, But..... it seems to be larger and the 'plug in' is in the center instead of on the side. Very easy to read digital numbers (and colors of red, yellow, green). cost me 15.00. I think that it is money well spent and I know that Wally World will take it back if I break it... ( I have not broken this... just some other things and have had NO hassle on a return)