AMP Gauge Questions

1. How to hook up AMP gauge. Got water, oil pressue, and fuel gauge working
2. If that not pratical (I hear lot of horror storys, fires, etc), does anyone make aftermarket Volt gauge that is rectangular?

Car is a 48 DeSoto, 12 Volt.

Jackie

 

Ammeter should'nt care about voltage change, just reverse the wire(s) on the meter if you made a polarity change.

 

output of the charging system/alternator/generator goes to the + side of the amp gauge , the - side of amp gauge goes to the battery. power for the rest of the electrical system comes from the + side of the amp gauge.....these are the only wires that attach to it

 

Just keep one thing in mind, all the power for the whole car except to the starter goes through that one wire, make it the right size and quality. It will give no trouble when done right.

 

Any problem with running a wire from the + terminal on the solenoid to the + on the amp gauge and from the - on the amp gauge to power up the fuse block?

 

Like this:

 

Maybe something like this

 

Thanks,
Will give it a try, and post the results.
Jackie

 

Just a quick note here, there is no negative side to an ampmeter. It does not have a negative connection to it. That would be a voltmeter. The ampmeter is wired in series with the load it is to read.

 

Say again, in terms even an idiot (me) can understand?
Jackie

 

i am so confused!

 

ignore any "horror stories". Ammeters were standard equipment on cars from way back when to who knows when before idiot lights and volt meters came into vogue.

I ran amps in my Hot Rod Datsun pickup for 10+ years and never had a problem. I like them. tells you of a discaharge situation before the battery gets sucked dry.

 

Ammeters are the way to go. I hear horror stories all the time about fires, but I've never actually laid eyes on a car that burned up because of an amp gauge.

Side not, all Autometer ammeters have a "+" and a "-" terminal.

 

yes, i agree...an ammeter is wired in series and a volt gauge is wired in parallel

where i differ from you is the negative and positive on an ammeter. i don't know what gauges you use , but every automotive ammeter i have seen and used that shows a Discharge-0-Charge had + and - terminals on it. how else would an ammeter read properly? maybe 440roadrunner got your meaning

the way i described how to wire one in my first post is the proper way....nothing from the gauge goes to ground. the - terminal goes to the + post of the battery. power for the system and the output of the alternator/generator goes to the + terminal. that way if your system is using more power than is being produced by the charging system it will show a discharge....if the charging system is producing more than you are using it will show a charge. if both charge and power usage are the same , it will show 0. what Muttley posted make no sense to me (no offense)

front side:



if you look close you can see the + and - terminals

 

It doesnt make any sense to me either, thats why I asked if it would work.

 

I'm much better with visuals, is this correct?

 

I know this is a generator but the big wire coming from the regulator is the same wire that comes from your alternator.

I f you think about an ammeter as being a flow meter that not only shows the amount of amperage moving but also the direction of the flow. Notice that all the feeds for the lights and ign. etc. come off between the alternator and the ammeter.

When you turn the key on power flows from the battery through the ammeter (showing a discharge) and on to the ign. switch. Once the engine starts and the alternator starts charging, the power comes from the alternator through the ammeter (showing a charge) and on to the battery recharging it. If you wire it this way anything that is left on will show a discharge on the ammeter. Brake light switch stuck and you don't know it??? It will show a discharge on the ammeter when the key is turned off. If you wire it this way and get into a habit of glancing at the ammeter as you get out, you will never come back to a dead battery because you left something on like the lights. You will see the discharge and know that something is wrong. Can a volt meter do that?

I always use a fusible link in the ammeter wire. My cars are usually as simple as the above diagram. I did have an alternator short out inside once. The ammeter became a victim of the alternator short and certainly not the cause. A fusible link would have saved the ammeter and the wires. If you have a lot of modern accessories you may want to use a maxi fuse in the wire. Like a smoke detector in your house it will probably never be needed but you will happy it is there if it is ever needed.

This scan is from Don Francisco's Spot light book " Wiring Systems" written before alternators were popular.

 

As I read 36-3 post, I understand, then other post get me all confused again.

- on Amp gauge to + on battery
+ on AMP gauge to + (charging) on alternator

Is this correct? If yes, that seems pretty straightforward and simple.

Jackie

 

You guys are making my brain itch, I sent a PM to 36-3Window and he said yes, the diagram above is the way to go. You say no. I propose a steel cage death match to determine who's got the right advice.

 

on what you call the + on the solenoid , i'm assuming you mean the post where the + side battery cable is attached. you need at least 10 gauge wire

i'm not saying this is the only way to wire an ammeter , just the way i do it so it reads properly

i will also say that i'm not a big fan of ammeters and would not use one anymore , i prefer a volt gauge. mad-max's suggestion of a max-fuse or fuseable link is a great idea..i use them

 

Yes.

 

I did my car using a Painless kit. They have a Buss Bar on the back of their fuse panel with two #10 wires coming off of it.

One wire (called 915) goes to the alternator. The other wire (916) goes to the Solenoid through a Maxi-Fuse. But these wires go to the same place (buss bar) on the fuse panel side.

Also connected to the solenoid is a cable from the battery.

So, you can visualize the ammeter being placed between the alternator and the battery #10 wires. The negative(-) wire of the ammeter going to the junction of 915 and 916, and the positive(*) going to the solenoid.

Alt ------915--BUSS--916---(- amp +)--(maxi-fuse)---- Solenoid---Bat

But Painless also does not recommend ammeters for circuits above about 60 amps. They actually recommend you run a #8 wire from the alternator to the maxi-fuse which shunts a lot of charging current direct to the battery.

You have to use one design or the other. If you have a high current system, they recommend a voltmeter.

Painless Manual