I decided to replace my generator on my 54 desoto firedome with a 1 wire 6v positive ground alternator. I got the alternator bolted up this afternoon but I'm a little confused on the wiring. I ran the wire from the alternator to the batt terminal on the voltage regulator and disconnect the arm & field wires. I had 2 wires under my arm lug on the voltage regulator and one under the field. After disconnecting them I now have a no start. Somewhere I'm missing something. My wiring harness is all taped up and I ran out of daylight. So I'll have to try to sort it out tomorrow. Any idea why there is 2 wires under the arm and how should I go about configuring this now? I attached photos of the regulator and generator while it was installed.
How many wires under the battery terminal at regulator are there now after the conversion? A little lost on what it is your saying.
So basically the car won't start with. I think when I disconnected the wires from the generator and regulator one of them must of sent power to the ignition. One wire under batt terminal. One wire under field and 2 wires under the arm. I ran the alternator to the batt terminal on the regulator and disconnected the wires under the arm and field and now I have no no crank, no start issue. On my voltage regulator there were 2 wires under the arm. Not sure what the other one could be or where it should be hooked up to now.
After the conversion I have the original batt wire plus the new wire from the alternator under the batt terminal on the regulator
take all the wires on your amp gauge and put them on one terminal together this disconnects the gauge and makes one terminal a junction post , you cant p*** 90-140 or higher alternator current through a amp gauge thats made to have about 25-35 generator amps p***ing thru it ,it will, well rhymes with burst into flames , not a sermon but one to grow on ,,smiles for miles .. if in doubt google or search here ampmeters and danger or variations there of ... people will tell you its not needed and your car wont draw that ,,, kill the battery once and the alternator will go to full clip and it All p***es thru the gauge ,, fabricator john miss you dad
Are you sure there were two wires on the ARM terminal? If so, does the car have an idiot light for the generator, or just an ammeter? If an idiot light, that's what the second ARM wire would be for. With a one wire alternator that idiot light will not work. That's why I don't use one wire alternators, but rather install them as they were designed to be installed. In a typical generator setup a wire from the BATT terminal will go to the ammeter or ignition switch. It's likely that one of the wires you disconnected provided power to the ignition switch.
There are definitely two wires under the arm terminal and the car has an ammeter. When I find the wire, would I need to wire it over to the starter relay since the regulator is no longer needed?
Genatorators or alternators have nothing to do with an engines ability to start or run except charge the battery when the engine is actually running. I would just leave the regulator for now and let it serve as a terminal block.
That's what I'm doing, using the regulator as a terminal block. One of the two wires that were under the arm lug must send power to my ignition. Should I reconnect that wire back to the arm on the regulator or do I need to run that wire to my starter relay?
I suspect that it was mis-wired at the regulator before you started. What you need to do is identify the two wires that went to the generator only. Of the four wires connected, one goes to the battery, one to the generator armature, one to the generator field, and one that feeds the main harness. This last one is the one not connected and causing your problem. Typically this is connected to the Bat terminal. Find and disconnect ONLY the two wires to the generator, put the remaining two and the output from the alternator on one terminal on the regulator for a junction point. It doesn't matter which one, just use the largest terminal if one is larger. If the new alternator is capable of current output beyond 30 amps, you do want to disconnect/byp*** the ammeter. A low battery/high charge rate can exceed the ammeter's rating and burn it up. This will leave you with a dead car and a possible wiring fire. The only exception to this is if you have an inductive ammeter with no direct wire connection. These have no screw terminals on the gauge, just a metal 'loop' that the wire p***es through. If there's two wire screw terminals on the gauge, put both wires under one screw. If you do have an inductive ammeter and high current output from the alternator, the ammeter may fail anyway but it won't kill the car.
Thank you everybody for your help and expertise. As it turns out, the 2nd wire under the arm terminal is the ground for relay solenoid coil. I grounded the wire and the car started right up. The alternator is charging correctly and the ammeter is working as well.
Glad you got it going. Sound advise was given on the ammeter, they are a known problem. My question is if a person wanted to keep the original gauges operational, can an old ammeter be converted to a shunt type ammeter? This would limit the amount of current p***ing through the gauge yet give an indication of charge or discharge. Crazy Steve is pretty savvy on wiring. He may know if it is can be done safely.
It's possible to convert a direct-read ammeter to a shunt type, but it comes with other issues. Basically what you need is a current-dividing circuit, the trick is getting your resistance values correct. You'll be talking very low numbers, too low to accurately measure with the testing meters available to us. Too little current shunt, you still have a fire hazard, too much and the gauge won't read much of anything. ***uming you manage to find that balance, it also reduces the sensitivity of the gauge to where it may not register small values, only large ones. That's fine for catastrophic failures, not so much for developing problems. The typical factory shunt-type ammeter is designed/calibrated to read these smaller values. The other bigger issue is an ammeter is nearly useless for monitoring an alternator for problems in a vehicle. Same thing goes for using a voltmeter with a generator. This has to do with how each works, while both use the same basic principles the mechanical/electrical differences between them make one or the other type gauge better choices. Without going into a deep dive into theory and how the mechanical differences affect that, what it boils down to is when generators (not regulators) start failing, current output falls, not voltage output, so an ammeter will show that. An alternator is the opposite; they can maintain current up to a point, but voltage output will drop before you see that. Again, either type gauge will show a major charging system failure in the 'wrong' application, but you can get more-or-less the same protection with an idiot light.
To solve the ammeter problem, you can get a voltmeter and paint the face to match the other gauges. Then you can scan or take a picture to copy the lettering/font, have that cut with those "printers" that cut stickers, this will be your stencil to paint the letters/numbers/whatever and voila you have a "factory" voltmeter.
Steve, thanks for the information, that all makes sense. The shunt type ammeter in my OT ford product never indicates much at all. I was hoping the OP was taking the concerns about keeping his ammeter in the circuit to heart.
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