Hi folks. I'm the New Kid 😁. I'm resurrecting a '48 Chevy. Chevyofthe40s says it has an Ammeter NOT a voltmeter. And I therefore won't need a dropping resistor to use a 12V system. I want to use all original gauges. So QUESTION: Which post on the Ammeter gets 12V Positive and which do I ground?
There are no marks to indicate it and I am the 4th owner in trying to bring it to life. So I didn't take it apart. (I have a '49 Studebaker pickup, so I'm not all bad). Thanks in advance.
Hello Kenny, please do NOT wire your ammeter to ground. I just saw a post that shows how they are to be wired, but surely someone else will chime in soon.
Also, please drop into the welcome forum and introduce yourself to the TRUCK FORUM, where car questions are usually sent to the greasy spoon to be resolved.
here is the link that will give you an idea of how things are normally wired! https://www.vintageautogarage.com/v/vspfiles/files/alt-wire-diagram-10.14.pdf
Might be a good idea to learn about simple electricity someplace to learn how it works, pretty simple, just a few basics would help.
Ammeters do not care about voltage, just flow, so, if one turns on the headlights or some other load with the engine off, the ammeter should indicate negative, if reads positive, just change the leads. The whole electrical load less the starter, should feed through the ammeter, lead goes from the starter large starter terminal directly to the ammeter to feed the whole rest of the truck, which gets fed from the other ammeter terminal.
I just rewired my '49 Chevy 3/4 ton Step Van. The way I did it is I ran a 10 gauge wire from battery terminal on Solenoid to the D (Discharge) side of ammeter and a 10 gauge wire from D to St on ignition switch. Then with the same gauge wire I ran from bat. (battery) on ignition switch to C (Charge) side of ammeter. My ignition switch has 4 terminals (Bat., Acc., St., & Ing.) St. is in center with the others in a triangle shape. This worked for me.
I am seriously thinking about changing from my gen./reg. to a alternator. I keep hearing about a one wire alternator set up, meaning going from the alternator Bat. terminal straight to the battery. One would think there has to be more to it than isn't there?
I have a one wire alternator and it is that easy, but there are drawbacks. Here’s an article by Rod Authority that points out the differences. One Wire vs. Three Wire Alternators