So I have searched and searched and found many post on 6-12 volt conversions; however, many of them differ. I have a few questions about the conversion I'm doing on my 53' Pontiac. things I could use some advice on: I wired the BAT terminal on the alt(10si) directly to the positive terminal on the starter. I got the ballast resistor for the coil, but i skipped out on that whole diode/DA Plug... I don't know what this is all about. some say to get this DA plug and wire it to the ignition terminal or else your car wont turn off when you cut the key? I skipped this and my car turns off. Half of the 12 volt conversions i read about included this plug/diode and the other half mentioned nothing. Whats up with that? I'm not using any of the Gen/f/Bat wires that were on the regulator, anything wrong with this? Is there a way to tell if my alt is actually charging my battery, short of waiting to see if my battery dies? I believe the volt gauge pulls of the alt, but how do i know that the current is actually making it back to the battery? thanks in advance for all help. -Chris
Not enough information yet. There are two alternators in common use: 1) 3-wire alternator, has a two-wire clip. 2) 1-wire alternator, no clip. You hooked it up correctly if you have a 1-wire. The way to tell if it is charging is to look at the volt meter. It will read about 11 volts, and then when you start the car it may still read 11 volts until you burp the throttle and get the RPM up, where you will notice the voltmeter go to 14 volts and stay there. 14 volts means you are charging. The 3-wire alternator has one wire folded over and connected to the BAT terminal. The other wire is called the "exciter" wire and this goes to the ignition switch. I have found an idiot light wired in series on the exciter wire works fine, and others don't like idiot lights so they put a diode in there. It's this exciter wire that can cause the run-on. If you have a 1-wire, don't worry about it.
Take a screw drive,if the alt is charging there will be magnet field at back of alt and it will pull the screwdrive to the case.
this is a three wire with the clip. I was under the understanding that the one wire on the clip would fold over to the BAT terminal as the exciter, and the other wire was for the Volts gague. What is the purpose to go to the ignition switch? Thanks for the help! Chris
The single wire is self excited at a certain RPM level. Meaning they will start and then continue charging after that rpm rate is met. Usually about 1200rpm. The three wire is externally excited, that is the alt is signaled to start charging by telling it the igition is on. Wiring it to an ignition hot circuit tell it to go into charge mode. Problem is it will continue to provide current to the ignition circuit once it has started charging. So you need to put a diode or other resistance to keep the current from backflowing. As stated an inline light bulb will do the trick. The other wire is a remote voltage sensor which is supposed to tell the internal regulator how much to charge. This is usually hooked into an accessory that puts a load on the system, or a terminal block which feeds several accessories. A voltage gauge can be wired in series on this lead. As a lot of our cars don't have much in the way of accessories, finding a place for this wire can be problematic. so some folks wire this on back to the bat. If your car has a solenoid, you can wire the bat output to the battery side terminal on the solenoid rather than directly to the battery. I am planning on wiring my voltage sensing wire to the horn relay, as it is hot with ign on, and quite a few circuits pass through it.
Thanks Plym, Is it not true that you can excite the alt off of its own Bat terminal, and avoid running the light/diode. If i were to go to radio shack for a diode, what would i look for? Thanks again! -Chris
"I am planning on wiring my voltage sensing wire to the horn relay, as it is hot with ign on" Usually the horn relay ALWAYS has power so that you can blow the horn with the ign off!
276-1661 The stripe on the diode goes to the alternator. Use two layers of heat shrink tubing to cover it, and prevent shorts. The big wire on the clip is called the sense wire. In hot rods without a lot of accessories, everyone just folds it over and hooks it to the BAT terminal. On cars with power seats, air conditioning, power windows, yada-yada-yada, that pull 60 amps when the stereo is on, you need to wire the sense wire closer to the fuse box. This provides a more accurate sense point, that the alternator can regulate properly. Otherwise the regulator is chasing its tail, and spikes are likely. Edit: Note, don't put your voltmeter in series with any wire. Wire it to the switched 12 volts from ACC and ground the other wire. It is a parallel device, not a series device like an ammeter is. Have fun, Max
You can always go back to old reliable ammeter, which I believe was standard on your 53. Really pretty easy to wire. Just remember that it is put in series with everything (and the battery) except the big wire going to starter solenoid. This must go directly to battery.
No ya can't use the amp meter to do that. It is in the output wire of the alt. when wired correctly. The little diode is probably the best answer for you.
Thanks everyone, i got the diode in and everything wired up today. I don't have a digital multi-meter but I'm reading slightly higher with the car running than off. Next step, wire up the amp gauge. -Chris
I rarely use ammeters anymore. They have to be wired in series in the main charging wire from the alternator to the battery (or solenoid). That wire carries lots of amperage and all your charging voltage. It can get hot and if it gets a short you're dead in the water. You are also adding resistance by all the extra length to wire it through the firewall, to the dash and gauge, back through the firewall, well you get the idea. There's a reason new cars don't have ammeters anymore - just too easy to cause a problem, or like by buddies car, a fire that destroyed the car when it chafed on the firewall because the grommet rotted over time. Run a volt meter instead my 2 centavos
I used an ammeter in guys 4-wheel drive. Haven't used them in years, so I looked around, and as usual the aviation boys always have the good stuff. They are smarter than hot rodders, because they might have to jump out of a burning plane, and that's about 4000 feet higher than we have to Anyway, they have a sender (shunt) that you mount to the fire side of the firewall, and a gauge you mount inside the non-fire cabin. The wires to the sender are a calibrated length, so you don't cut them. I asked why he wanted an ammeter, and he said that sometimes the mud get's all over the engine, and clogs up stuff, and an ammeter is a lot more sensitive than a voltmeter. As soon as it starts showing discharge only, he can get out of the mud, pop the hood and pull some of the mud out of the engine area/alternator. http://www.wicksaircraft.com/catalog/product_detail.php/pid=820~subid=3393/index.html
I used a stock '64 Malibu shunt style ammeter when I built my car. The stock chevy shut looked like a ballast resistor. It broke on my first trip and caused quite a commotion as I tried to unload the trunk to disconnect the battery to stop the SMOKE! Two lessons were learned: Have a battery disconnect that can be reached from the driver's seat and don't use a stock shunt ammeter. I ran an aftermarket ammeter for years afterward and had no perceived problem. The aircraft style shunt shown would probably not be able to break like the stock one did. I finally converted to a voltmeter. The voltmeter seems to be easier to check for problems. I could never have seen a 2 amp drain on the ammeter (-60_0_+60) but I can see the voltmeter showing the voltage going down.
Just when I'm about to look for post on how to wire up the ammeter.... I think I'm just going to run a volt meter for simplicity and i don't like the idea of being stuck because a gauge went bad. I'm not a huge fan of this ballast resistor i have mounted on my firewall. It gets very hot and is ugly. If i get a 12 volt coil i can do away with the resistor? If i keep the resistor is it ok to mount on the firewall with no casing? -Chris
They are suspost to get hot ,thats how they work. You can get a 12 Volt coil that has a internal resistor. And no don't try to run the resistor open without the ceramic housing.
A lot of hot rodders use the ballast with a fan, as the only source of heat in the winter This is where it get's a little expensive. The manufacturers of electronic distributor modules recommend you keep the ballast resistor. It current limits the output transistor, and dampens the spikes. Both of which extend the life of the module. To really get rid of the ballast, you need a CD ignition box (Capacitive Discharge). Boxes like MSD, but there are others. That way the output transistor just acts like a pulse switch and the CD box does all the work. Not cheap, but affordable, and so much better. That said, many people run a pertronix without a ballast and do fine. 12 volt coils still need a ballast if you have points. Yes, mount the resistor up high on the firewall so the heat doesn't have to rise through any other parts (like the wire harness). Put it in an area by itself so it gets some air flow. The first thing I buy when I get a new project, is a pertronix electronic kit (whole distributor if the original is worn out), a set of plug wires, new plugs, a coil, and a can of air freshner. That alone doubles the value of most junkers, ha... I spent my youth doing points, condensors, and sitting on the side of the road. One thing to note about pertronix, is to use some locktite on the screws (the blue stuff, not the red).
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