I’ve searched and searched, can’t find a specific answer to my question. I’ve got a question about wiring my stock ammeter (1950 GMC Truck) to my 12v , 3 wire GM alternator (sbc 350). Would I be able to to run the batt wire (output on alternator) to one post on the ammeter, and then the other post on the ammeter to the battery? Essentially this would eliminate all other circuits on the charge side, and run the charge through the ammeter to battery, if I’m understanding it correctly. I know every diagram I see has the ammeter running to the starter, but I was wondering if I could eliminate this. This is a rat rod/resto mod project. The only other circuit on the truck other then the few wires to run the motor, are the head and tail lights, that’s it. No heater fan, AC, radio, nothing. Can I just run that ammeter in-line of the alt/batt cable?
You have a modern motor. Doing a "restomod". The answer is get rid of the ammeter (don't wire to it) . Run the alternator to battery as you said. Run everything from ignition switch and fuses. You can install a volt meter gauge or an annunciator light (My favorite)................. or neither. GM offered lights or gauges. Lights work for people who are not gauge watchers. Like 90% of the public. I always said give me the gauge option because I'm a man, a gear head, don't want no stupid lights. I never looked at any gauge except the gas gauge. When your truck won't start, you know you need to check the battery, the cables, then the alternator. Carry jumper cables and a cell phone.
Cable to starter from battery. Wire to alternator from battery. Use a fusible link Wire to ignition switch from battery. Use a fusible link Fuse panel can have switched hot fuses and always hot fuses. Sounds like you know how to do the ignition start and run circuit and lights.
The 3 wire alternator is really two wires leaving alternator. I.E. Battery pos post to Alt pos stud and blade 1 terminal to a bulb, thru bulb to ignition switch "ON" terminal. Blade 2 is wired to alternator hot stud.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
Everything is done and running now. I had a “hot starter” issue so I wired in a remote starter solenoid on the firewall. The ammeter is not hooked up right now., I was just driving it the other day and looking at all the other working gauges, and was wondering if I could just wire that ammeter up without frying it. While keeping the stock gauge, and retiring everything I’ve already done. I’m not sure I would call a gen 1 350 a modern motor...
I like to do the Ford remote starter relay also. OK, your motor is not modern. So you are doing a Resto-old I guess. If you want to wire the ammeter. It gets one hot wire from the battery. They came from the starter stud because it was a nice place to get battery positive. All the loads are on the other ammeter terminal, including the alternator.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
To clarify my previous post to match your remote starter relay.
Cable to starter from battery. Cable from battery pos post to relay input. Cable from relay output to starter pos stud Big gauge jumper from solenoid "S" terminal to solenoid batt stud Wire to alternator from battery or relay input. Use a fusible link Wire to ignition switch from battery relay input. Use a fusible link Wire from relay "S" terminal to Ignition switch "S"tart terminal.
Poster calls it a "Hot Starter" issue. The remote relay trick has no small wires down to starter. Those solenoid and coil bypass wires get radiation from motor and exhaust heat. Sometimes the wires get so hot that resistance is too high and starting is hard till they cool. A form of heat soak. Also the insulation gets hardened/browned on some vehicles. Anyway, I do this all the time. The solenoid and the starter get heat soaked also/more so. This big jumper from the big cable can overcome the internal resistance and force starter to spin in some cases. I guess a shield helps also. Especially for headers. The up-top inner fender mounted relay is pretty nice to trouble shoot and has good "hot wire"/remote start button access. I make the jumper from small flattened copper pipe and drill two holes. The "I" terminal on the relay gives you the "R" to coil + bypass circuit if you need it. I gave the relay part numbers in pic.
Don't know if poster did this, but this is the method.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
I agree. Lose the amp meter. Install a voltmeter in it’s place. I never thought running high current wire through firewall was a good idea, others would differ. It is a rat rod after all. Oh, BTW....we pretty much think any motor that doesn’t have all it’s six cylinders in-line is a new motor🥴. Spoken by a guy who has a v12 flathead in his shop.
