As some of you may remember, I drive around with a cheap voltmeter gizmo that I keep plugged into one of the power ports. The nice thing is they have red, amber and green LED lights so the driver can monitor the battery(ies) and charging system without knowing anything about how the system works. If the light is green, then everything is OK. If the light is amber then monitor with caution and check the battery connection for corrosion. If the light is red then something is wrong.

Well, last week I was sitting at a stop light and I glanced over at the meter and saw that it was red. Sitting right at 12.50 volts and decreasing at idle. As soon as I began driving and the engine speed increased then the volts would rise to the low13s and the light would turn amber and then turn green at cruising speed.

Park the truck and turn off the key the volt reading would be in the 12.6 range with a green light. So, I only had the red light with the engine running....and only at idle. This tells me the alternator is beginning to fail most likely a few bad diodes. Since the meter gave me plenty of advance notice, I was able to drive like that the rest of the week and schedule a convenient time to change the alternator. I keep a Ford alternator as a spare just in case I ever need one. (I won't use parts store alternators...)

So, I had a spare 20 minutes and changed the alternator last night. Volts were right back where they should be (14.05 at idle). I really like these volt meters. Very practical things to have....especially for what they cost.

The OE alternator on this truck lasted 333500 miles. Not bad at all. I think I'll drop it off at the generator repair shop and have them rebuild it for me. Should be around $90-$100. I'll then keep it on the shelf for the next time that one of our trucks need alternator. Might sit there for a while....

 

What a boring thread. What no power gains or turbo whistle? I have a spare Ford alterantor also, along with a volt meter that plugs into a power point. Thanks for reminding us that there are other things that are just as important as power. After all, power don't help when when you don't have any power.

 

LOL Jim!

And x3 on the volt meter, amazing bang for the buck. After being predictable for years a gradual increase in voltage drop when cranking showed my batteries were getting tired. I like advance notice and changing them at my convenience over waking up to a slow or no start one cold morning.

 

I miss the old days when there were ammeters that showed you charge/dischage current, but keeping an eye on an accurate voltmeter (especially one with LEDs for different ranges) is just as good. Too bad the factory voltmeters are about useless when trying to gauge (pun intended) the condition of your electrical system.

 

I have that exact volt meter also, I tend to forget about it. Plus, between satellite radio, GPS, tablet and iPod there is rarely an available outlet for it. I need to get a nice multi outlet assembly for the bottom of the dash.

 

I think the charge bar on the side of the display might be intended to be an amp gauge. It hovers right in the center when the battery is fully charged and is just a bit over center for a few moments after the engine is started.

My '76 Corvette has an amp gauge. It's pretty cool. I like to watch as it recharges the battery and eventually settles in the the dead center position between charge and discharge.

My wife drives a 2000 Power Stroke and all she knows is what the lights mean....she has no clue if 14 volts is good or bad. She actually sits in the driveway until the green light comes on. In the winter she sits there for a bit longer. She gets mad at me when I drive her truck and don't wait for the light to go green. I just laugh and she gives me the evil eye (presumably for treating her baby so poorly).

 

I see you changed to a different meter from the one you have listed in your original thread from years gone by. I changed to a different meter in my truck too, but still have the same ones in my Ex and my Lightning.

Stewart

 

I needed a smaller one in my truck, so I changed to one like this:



Stewart

 

I bet if you put it in a dodge you would gain 100 horsepower and get another 10 miles per gallon

 

Greg thanks for bringing this subject up because it was a thread like this 2-3 years back that I had gotten one. It is a Vector VEC008 Digital LCD Voltmeter and it too has the little lights. This thing has saved my butt a couple of times. First time it saved my rear was it let me know that my GPR was bad. Mind you I have a small LED GPR light that draws next to no amps to light up. Well I would go to turn the key to on and wait to start light and GPR light was on but when I looked at my little gauge the voltage was about the same as key off. Normally the gauge goes down to like 11.2v to 10.5v and that time key off was 12.5v and key on was 12 volts. Took a dvm to the GPR and only had like 1.7volts on gp side. The second time was when the alternator was getting ready to go out.

Speaking of alternators when I replaced mine I went with a NEW Advanced Auto 6.0 alternator 140 amp. (Factory alternator lasted 200k) It came with it's own print out of test data and a lifetime warranty. The 6.0 alternator was about the same price as a new 7.3 110 amp alternator. Where I have an issue with parts stores is their rebuilt alternators, they are all JUNK ! I believe you rebuild engines NOT alternators and a/c compressors. The parts stores ones are rebuild in China or Mexico. Now if you can find an American that takes pride in what he does to rebuild one for you it should be ok.

You are a lucky man to have a wife that checks gauges. It has taken me 7 yrs to teach my wife where the gauge needles should be. But she forgets to look at them.

 

Well after reading this I thought "Hey I've notice some inconsistent readings on my scan guage lately". Took Her for a drive after reading this and I'm in the 12's at idle and high 13's while driving neither of which is on par to my normal readings. So thank you for this post hopefully I can get a new one tomorrow. I am driving from MI to WA in a couple days so I'm trying to figure out my next move.

 

Stewart where did you get that meter at i need one.

 

Yeah, the first style that I purchased didn't last long so I decided to try something different. It also didn't fit my F-650 dash since it was offset from the plug socket. The Innova model seems like a nicer unit and better quality construction.

I noticed it has a battery icon to indicate when it's in the battery monitor mode (engine off). In that mode, the gauge on the right show battery charges sort of like a cell phone or mobile device might do. Then when the engine is started, it switches modes to monitor the charging system. In that mode the gauge on the right works a bit like a amp gauge. At least that is how it appears to function for me. It probably had instructions in the packaging but I must not have noticed.

 

Yeah, the GPR LED mod was a good idea with good intentions but it doesn't really tell you anything except that the PCM has sent the signal to close the relay....it doesn't really tell you that the relay is working. A volt meter will give a clue if you know what readings to expect.

I have a generator shop that I've been using for years to rebuild stuff like alternators, generators and starters. It's an old timer shop.....pretty good size though. They get a lot of business so I hope they stay around for many years to come. They do great work.

My wife is a character. The only two gauges she looks at are the fuel gauge and volt meter. Everything else could be in the red and she wouldn't notice unless lights start flashing and bells are ringing.

Her truck has been super reliable. She has only had two issues so far to date. She ran out of fuel once and another time she had a no crank when the batteries died. Now she never lets the fuel get below 1/4 tank and watches the plug in volt meter like a hawk.

 

The dodge versions have a longer neck and then both sides of the display flip out so it looks bigger. Takes up too much room.

I have a plug in meter that looks like that one. I don't leave it plugged in all the time, but it stays in the cubby on my door panel and I plug it in every now and then to check things. Mostly on the first cold start of the day.