wiring in amp gauge

[dave71]

i have been looking thru here and never found the answer i'm looking for so with that said here's the ?

 i have an amp gauge but don't know how to hook it up this was in box of misc parts i had in the shed.. just need what to hook the + wire to..

[DanielC]

Do you want info for the 71 521, or the 79 k/c?

 

What it the amp output of the alternator on the truck you want the amp gauge in?

[dave71]

the 521... it's just a stock alt on the 1600

[datzenmike]

I don't know anybody who runs an amp gauge. Just get a voltage meter.

[thisismatt]

An ammeter requires that the full current load flow through the meter itself.  This means you have to run heavy gauge wiring up into your dash from your alternator, and then back to your battery.  This is a hazardous situation, and adds more failure points in your electrical system, not to mention the gauge has to be able to handle all that current.  Nobody with an electrical system anywhere near modern runs an amp gauge.  Heed mike's advice and run a voltage gauge instead.

[thisismatt]

Here's a good read about the subject, from a source you might find more convincing:

 

http://www.autometer.com/tech_faq_answer.aspx?sid=1&qid=5

[DanielC]

Back in the day, we ran amp meters, AND WE LIKED IT!  Along with points in distributors, and carburetors.

 

On a stock 521, the positive output of the alternator goes to the starter, on the same terminal as the positive battery cable.  There is also a wire from the battery positive to the fuse box.

 

Before working on the wiring of your 521, disconnect the negative battery terminal.  This is especially important if you add an amp meter.  You are working on wires that are always hot, if the negative battery cable is connected.

 

To add an amp meter, disconnect the battery positive to the fuse box wire.  Battery positive, EXCEPT FOR THE STARTER CABLE goes to the amp meter.  The second terminal on the amp meter goes to the fuse box, where the old battery positive was.

The wire from the alternator positive to the starter is disconnected from the starter.  This wire now goes to the fuse box, where the old battery positive wire fed the fuse box.  It will have to be made longer.

 

Both terminals on an amp meter are hot.  All the time.  They are never grounded.  The wires to and from the amp meter must be able to continuously carry the full output of the alternator, or the full electrical load with everything on, whichever is greater.  With a 35 amp alternator on a 521 that means at least 10 gauge wires to and from the alternator, to the amp gauge, and back to the fusebox.  8 gauge would be better.  The entire length of these wires is always hot, and needs protection the entire length to and from the amp meter to the battery, and alternator.

 

If you do hook up an amp meter, before starting the engine, turn on the headlights.  The amp meter should show a minus indication.  If it shows positive, switch the two wires on the amp meter terminals.  Disconnect the negative battery cable before making this change.  Did I mention these wires are always hot?

 

The main reason cars went to volt meters is because they are so much easier to wire into the system.  Voltmeters do not require heavy gauge wires for the volt meter, through firewalls, and back that are always hot.  Volt meters do not require the entire length of these wires to be insulated from ground, and protected from abrasion for the entire life of the car,

[dave71]

what i have may just be a volt meter.. it's on a triple gauge cluster oil,water & volt the first 2 are easy to hook up but it's been so long since i did a volt meter i don't want to fry my wiring harness or burn my truck to the ground or shock the livin shit out of my self lol... since the terminals seem to light to be an amp meter it must be a volt meter now how do i wire that up

[DanielC]

On your fuse box, battery side of the fuses, three or four are always hot.  Two or three fuses are hot only when ignition is on.  Connect the volt meter positive there.  The other side of the volt meter goes to ground.

[dave71]

thanks :thumbup:  i'll let ya know how it turns out... i figure it's better ask cause even the simple  :poop:  will bite ya in the ass if you do it wrong :blush:

[Ranman72]

when I was younger I had an amp guage something happened to the wire and it smoked out the entire cabin in a few seconds

I jumped out of the car to pull the battery terminal wich was hotter than hell but before I got it un done the wire wich was bare and glowing red hot

burned in two and arced accross the brake line and blew a hole in it

 

THIS WAS THE END OF AMP GUAGES FOR ME

 

I would suggest a volt guage it tells you better whats going on in a safer way

[lostforawhile]

there is a reason most people dont run them anymore,  they started a lot of fires back in the day,  volt meter is much safer and will tell you the same thing

[banzai510(hainz)]

theres different version of this

http://equus.com/Product/3721/Battery-Monitor

 

 

if you have a triple gauge cluster thats made in taiwan get soemthing better.

 

if I would do it all again I would use a xducer type oil sender(usies a wire not a cheap plastic line that will break. I will!)

and a volt meter or buy thee one above or different version of this. they work great.

 

AMP meters have to be wired in series. plus looks tack depending who wires it up.

[lostforawhile]

honestly the best thing you can get is the SDC heads up voltage monitor, they were invented for motorcycles so the module is tiny, one single easy to hide LED, if voltage is in the normal range it's green and dims,so it's not a distraction, if the voltage goes to high or low, the LED changes color and goes to high brightness, it changes color depending on the voltage condition. It's very intuitive to learn what the colors mean, and you have an instant warning if you have an electrical issue, I went to a lot of trouble to hide the LED to make it look like a factory icon on mine. my volt warnining light is now a clear icon, so I can see the three colors of the indicator, the inidcator also flashes in a severe high or low voltage condition

[racerx]

get a volt meter...much more practical.