The Stovebolt Site Forums The Shop Area The Electrical Bay wiring to 55 chevy truck amp meter

I am wiring my 55 truck gauge cluster with a wiring harness from EZ wiring and it doesn't tell me what wires go to the amp meter positive and negative terminals. can anyone tell me where these wires need to come from.

+ terminal from battery, - terminal to gen/voltage reg. Some items are attached to the batt side and are not read by the meter.
The + and - is "voltage polarity". It's all positive, not ground type negative to positive.
If no markings on meter, hook it up and with motor OFF, turn on lights. If meter does not read in the neg direction, reverse wires.

Here's a diagram from a Delco service bulletin from the early 1950's. It's common to virtually all DC generator systems back then that used an ammeter. The circuit from the battery to the ammeter will be the same one that runs to the starter switch. Connect a #8 or larger wire from the battery cable connection at the starter and run it to one side of the ammeter. Make ALL other connections such as headlight switch, ignition switch, regulator BAT terminal, etc. to the other ammeter connection. If the meter reads "discharge" with the engine running and the generator producing current, reverse the ammeter connections.

http://www.hunt101.com/data/500/D-R_Regulator_001.jpg

Jerry

Thanks for the information. I am using an alternator with my truck. It looks like from the information provided, I could put the ammeter in series with the hot line from the starter/battery to the ignition switch. would that give me a true reading? Does anyone know if there was a voltmeter option for this gauge?

Unless you connect the alternator output to the ammeter opposite the wire going to the starter, the ammeter will just be there for decoration. It will never show a "charge" because the charging current will be bypassing it. In about 5-4-3-2-1 seconds, somebody will show up claiming that an ammeter is a fire hazard. Never mind the millions of them that haven't been setting vehicles on fire since the 1930's!
Jerry

Millions of people used to use candles for light. A few thousand lit their house on fire. But it was only a small percentage. Maybe 5-4-3-2-1 per cent. Tell that to the folks who lost their homes. Then Electricity was invented and they "saw the light".

A voltmeter is a little safer, no melted wires or shorting the whole truck out. Same information about charge and battery condition. You can find one that looks era correct or put an era correct face on it. Most auto makers now use volt meter or warning light.
With your alternator, a voltmeter provides more useful information about alternator system performance compared to the ammeter. According to many technical/electrical experts. I can quote the reason if anyone wants it.

If an ammeter were to go bad, would it not just be an open circuit, no fire, maybe a millisecond of a puff of ozone, just like a blown fuse?

Believe me, I was careful not to say fire in the same sentence as ammeter. Todays wire is pretty tuff to start on fire. If a person wants to run a honkin 6 or 8ga wire to a dash meter, I say "more power" to them. If an alternator shorts or some other device shorts, this may cause a melt down at ammeter or elsewhere. Depending on what safety devices are installed. A small wire to and from volt meter scares me less. A good ammeter has a shunt bar and meter movement circuit. If the meter movement quits, no sweat. If the shunt bar fails, could be trouble...but it won't fail.
I post to give a balance to 5253chevyman, not to argue with Jerry. 95% of the auto forums and all of the wire harness companies say use a voltmeter. Just as when I had to fix my 150 HP mercury outboard, I read a lot of stuff to get temporarily smart and to keep up with technology. This is what is said about ammeters and it makes sense. The only good thing said about ammeters is "I never had a problem" after someone says they had a problem. As far as the value or quantity of information being inadequate from a voltmeter, That myth has been busted. One guy said an ammeter will tell him if he left his lights on and a voltmeter won't. He always looks at it before it gets out of his truck. Why don't he look at his lights after he gets out of his truck? Why don't he look at his light switch before he gets out of his truck. Gosh all Friday, people! (Carl, I know it's "doesn't" but I'm on a Ranch)

It is a 40 year old "argument" and I had to take Jerry's bait....a catfish would have said fire, I'm a trout.

Trout is good, but catfish tastes better- - - - -thanks for hitting the bait. I enjoy the meal either way!

"A fish is an animal that lives in a brook- - - -
He can't write his name or read a book- - - -
He lives in a school but he can't be taught- - -
And though he's slippery he still gets caught!
But if that kind of life is what you wish- - - -
You might grow up to be a fish!"

I love 1940's music!
Jerry

Maybe I said it Bass-ackwards, dang it! I love fishin, spring spawn is coming soon. Bass, watch out! Jerry, you can call me jerk bait and I won't get mad.

Here in Tennessee, crappie season is just around the corner- - - -nothing better! A couple of nearby lakes have "hybrid" crappie stocked- - - -about one pound or a bit more, average! Twice normal size!
Jerry

How's Bill Dance? A TN boy.

One pound crappie! Now that is some good flathead bait right there.

Well, the 60-lb. Halibut I filmed Dad catching on Cook Inlet was called a "minnow"- - - -two brothers on the same trip caught 150 and 175 pounders! That was the day after he caught a 78-lb. King Salmon on the Kenai river!
Jerry