Here's the details: Putting a new wiring harness in the '62 Suburban. I have a fairly rare '60 Chevy Truck full instrumentation gauge cluster. From '62-up, they came with a gas gauge and idiot lights. '60-'61 some had optional water temp gauges. The big trucks (I think), had full gauges: Water, Gas, Oil and Volts--Oil pressure gauge is mechanical. My truck has later GM Alternator, and HEI. The instructions from American Autowire (are VERY good) show three different wiring diagrams for these trucks, covering all the styles of instrument clusters except the one-year only one with full instruments. They also have a diagram showing aftermarket gauges. Here is my question: To wire up the ammeter (volts), should I: A) run one terminal to a hot ignition (switched) and the other to ground (switched hot ignition sharing with the hot for the gas gauge and temp gauge), B) run the hot to the alternator or battery somehow and black to ground (the factory shop manual shows a hot coming off the battery, "T"-ing to the voltage regulator and continuing to the gauge, black goes to ground) or C) some other option I'm missing. If I'm correct in my thinking, the voltage gauge should read volts through the wiring system, when the engine is running: wiring it with a switched Hot and Ground would read the voltage flowing through the system. When that voltage drops, or spikes, it will read that and tell me on the gauge, correct? OR, do I need to pick up that hot lead independant of the rest of the gauges in the cluster, from the alternator or the batter itself, and strictly read voltage at the battery or coming off the alternator, not juice flowing through the whole system? Thanks, Brad
I'm a little confused. Here we go: Ammeter: Measures current, and is placed in series. Voltmeter: Measures volts, and is placed in parallel Yes, run the "voltmeter" to the switched power at the fuse box.
Well, when it was originally a generator system, the lettering on the gauge face says "Ammeter" Now that it's an alternator system, the gauge face is still the same, but I want to use it to tell me what's going on with the alternator, so that'd be voltage. Same gauge, same job, different way of interpreting the info. ? Brad
if you have a ammeter , your option A would be a direct short to ground option b is a short too as stated , ammeters are wired in series..all power goes through it an ammeter should be wired with the outout of the generator/alternator going to the + side of the gauge..the negative side of the gauge goes to the POSITIVE side of your battery...then all power for your system the comes for the + side of the ammeter
It doesn't work that way. Amp gage only reads current(FLOW). Voltmeter only reads volts(PRESSURE). There is a wire in your harness that supplies power to everything except the starter(to crank). It usually goes from the battery cable connection on the starter to the ignition switch. Reroute that wire from the starter to the ammeter- and the other teminal on the ammeter to the ignition switch. Turn on the lights. If the ammeter deflects to "-", you're good. If it goes toward "+", swap the wires on the ammeter. When you start the car, the ammeter will move to "+" as long as the alternator is charging. If it drops to "-", ya got charge problems. Dan
If it is the same gauge it is still an ammeter! Did you change the gauge to a voltmeter and keep the face? If you hook one side of an ammeter to 12 volts and the other side to ground you will let the magic smoke out of the wires!
An ammeter is an ammeter and a voltmeter is a voltmeter. They are not exclusive to either a generator or alternator system. Just becuase you switched from one to the other does not make your ammeter a voltmeter. Hope this is of some help http://web.archive.org/web/20060208063157/http://6066gmcguy.org/ammeter.htm
The best solution would be to convert the ammeter to a voltmeter. If you know electricity that you may be able to do it yourself. Otherwise send the gauage out and have it done. I recommend Williamson's ( www.williamsons.com ). They can make a new face that will match the old one but read volts rather than amps.
be careful! sometime in the early 60s they switched to a different type of "byp***" ammeter, that is really a voltmeter...it is connected to two different points on the main power wire, and measures the voltage drop, and displays it as charge or discharge. That's how my 66 Suburban worked. The giveaway is that it uses very small wires, while an older "real" ammeter has big fat wires going to it. Also, as far as I know the full gage package was a common option starting in 1960 or 61 when they first quit being standard equipment on 1/2 thru 1 tons. I don't seem to have any info on those ammeters handy...maybe you could take a picture of the back of the ammeter and we can figure out what it is?
That is close, but not quite true. It is a shunted ammeter, there is a resistor on the back that shunts the current to keep from overloading the circuits in the gauge. So it's wired a bit differently than standard ammeters. I'll see if I have a diagram to post.
Yes, the wiring diagram in the factory shop manual labels it as a shunted ammeter. It has one terminal going to ground, the other terminal is hot from the battery, has a "T" intersection going to the regulator, and continues through the firewall grommet to the back of the gauge. But I don't know how the alternator and new harness will affect this. Typically I'm pretty good at reading diagrams and figuring out wiring, but I'm brain dead with the ammeter. I'll take a pic of the factory diagram tonight and post it as well, and maybe someone can tell me why there seems to be two diagrams for one gauge. -Brad
I have both Sun and Dixco ammeter installation instructions available. Hopefully show it a little clearer.
The only problem is that the Sun and Dixco ammeters work differently than the Chevy ammeter....so that might not be as much help as you hoped.
Here's a copy of the ammeter wiring diagram from the factory shop manual. If I'm reading this correctly, it's wired straight to the battery, and then to the instrument cluster's ground. The "T" going to the regulator simply feeds the regulator. So with my aftermarket harness, is there a reason I can't wire it with a switched 12-volt hot (from the ignition), like the rest of the gauges, or do I need to run a dedicated wire from the positive side of the battery? (I'm going to end up putting an aux. post somewhere, so that I can run a single lead from the battery to the post, and then pick that up for other things that need dedicated 12-volt power like a headlight relay, clock, etc.) -Brad
The Jalopy Journal
