Electricity Guru's to the resque

[78Suburban]

One more gauge to go now guys.. The Ammeter.
The instrustions say there are two kinds of GM wiring for this gauge. There is the voltage regualtor/horn relay circuit system........... and there is the starter solenoid circuit system...............

So is only one of those the correct way to wire my k20 burb???? How do I know which one? any tipes are welcome
Thank you,
James

 

[Big89Burban]

ammeters are a bad idea IMO. Having to splice into a circuit then run that through the firewall a couple times just doesnt seem like something I would want to do.

 

[78Suburban]

ttt
no one runs an ammeter? should I ditch it (it came in the kit) in favor of a voltometer? Whats the difference, I'm a little sketchy on my electrical theory..

Does anyone know which circuit I should use?

 

[bridgeguy]

Whats the difference, I'm a little sketchy on my electrical theory..

Keeping in mind that I'm a civil engineer and not an electrical engineer, the easiest way I can think of to describe the differences is that an ammeter tells you if you are charging or discharging. Basically, state of health for the alternator and charging system, but nothing about the actual voltage available. A voltmeter will tell you just that. Personally, not a big fan of running high current lines on the inside of my vehicle, but people have done it for years. Just be really careful about closing the circuit as if you have a metal band wristwatch and touch it to the live terminals, it's a really effective conductor sandwich with your wrist as the filling. Leaves really sweet scars.

It's handy if you have concerns about your alternator not being up to the task of putting out enough juice to run all your doodads but I'm more concerned about what the voltage is in the system as you can really cook some things with improper voltage.

You can always run a higher output alternator.

 

[78Suburban]

since I'm not big on the idea of fire hazzards, I'm thinking of just sticking with the idiot light for my charging system needs...
maybe I'll get a different gauge to fill up the thrid empty space..

 

[bridgeguy]

since I'm not big on the idea of fire hazzards, I'm thinking of just sticking with the idiot light for my charging system needs...
maybe I'll get a different gauge to fill up the thrid empty space..

Don't want to discourage you from getting SOME gauge to monitor your electrical system. Think about it this way: with voltmeter wiring, you're basically just running another ignition switched wire into your cab. About the same as the one running to your radio.

Personally, I'm all about voltmeters. They can save you in a big way as if your alternator goes out to lunch, you'll be able to see the voltage dropping off and be able to take steps to remedy that before you completely flatten the battery (turn off lights, heater fans, A/C, stereo, etc) but you don't have a high amperage feed in the cab.

 

[diesel4me]

I'd say..

I think a voltmeter will tell you just as well as an amp meter if its charging--an Amp meter needs 2 wires,both going to positive!--most only go up to 60 amps on the cheaper gauge sets,so I'd avoid using one if you plan on using a hi-amp altenator..I've burned up a few cheap ones that read 60 amps,after getting a jump start with a dead battery..

If you want to hook it up anyway,use 10 gauge wire at least--8 gauge would be better..I know the instructions say to wire it at the solenoid--but the battery + cable AT the battery is the same cable,and much easier to reach!..

I ran one wire right to the battery positive cable,and the other to a constant "hot" terminal on the fuse block--or you could also use the "junction block" near the brake booster that has the 3/16" threaded stud and red wires with fusible links for the other wire..I'd put a fusible link in one of the wires in case the gauge has a meltdown or the wires ever shorted..better than watching them glow orange,and burn the truck up..

A voltmeter will show voltage,not amps..but if you are getting 14+ volts out of you altenator,chances are its also putting out the right amount of amps too..a voltmeter needs a hot wire and a ground,the hot wire "hot" with the key in the "ON" position ONLY..smaller wires can be used,like 12 or 14 gauge,and a fuse in the hot lead is a good idea.. hope that helps you out!

 

[78Suburban]

..a voltmeter needs a hot wire and a ground,the hot wire "hot" with the key in the "ON" position ONLY..

If I were to get a voltometer, what wire could I tap into that would meet that requirement? Is there a good ignition only place on the fusebox to hook into?

 

[ZooMad75]

There should be a keyed on port to pull from in the fuseblock. I pulled keyed on power for my voltmeter from there.

One point on the ammeters. The reason they have to carry the high current is because Ammeters have to be in series to the circuit they are monitoring. Voltmeters monitor voltage in parallel to the circuit. Thats why an ammeter circuit is going to require running the high current circuits into the cab to the gauge and back out again. Plus if you overload the current capacity on the ammeter, it blows and the circuit is open, no more charging. My voltmeter could quit it does not interupt the circuit.

Voltmeter's give a better idea of what is going on with the charging system. Leave the ammeter on the farm tractor...