Ammeter never shows charging

Dave / Franklin MA

Dave / Franklin MA

Member
My ammeter never shows charging. I've had the car about 14 years and it's always been like this, and until recently I assumed that's right but now I'm not so sure.

It has a generator with a modern diode replacement cutout. When I put on the lights or the brakes it shows -10 or so like you'd expect so I believe the ammeter is working. With no lights on, no matter how I adjust the third brush, it will stay dead center at zero at any engine speed. The battery always has plenty of juice, but it scares me a bit that I never really know how much the generator is putting out.

What's the normal indication on the ammeter? Should it normally show it charging? Only for a time after starting? How much should it show? The generator section in Les Andrew's book isn't clear to me, as far as how it's supposed to work and how to adjust it properly.
 
Do a Ford Barn search for: ammeter, generator, and cutouts.
Read them and see what the members recommend for charging rate. I've seen 2-3 amps @ idle and 7-10 amps when driving down the road.

Find a shop that can check your generator for output and overall condition.

There are many members on this site with much more knowledge of this matter than myself.

I had a partial rebuild on my generator last week and it is set for 10.4 amps max at driving speed.

Ammeter should always show a charge @ idle or @ speed if no lights, accessories, etc. are on that would cause a draw on the battery.
 
I have a Fun Products cut out and it does the same thing, never had a problem with the battery. I have read there is way to wire it so it read when its charging. :confused:
 
Your battery was ready to die 13yrs11mos21days ago
Could your amp meter be bad? What's the voltage when runing lights off and lights on?
 
With the exception of a two second charge following the car's starting, my amp meter is also pinned to 0. Discharge reading with engine off is dead on, but there is no movement of my meter dial with engine on, even with high beams on while ahoogahing. My battery is about eight years old and I do a lot of daytime and night driving though I do have a 6 volt alternator with a diode set that functions like the the one(s) on Dave's generator.
 
Bruce Adams said:
With the exception of a two second charge following the car's starting, my amp meter is also pinned to 0. Discharge reading with engine off is dead on, but there is no movement of my meter dial with engine on, even with high beams on while ahoogahing. My battery is about eight years old and I do a lot of daytime and night driving though I do have a 6 volt alternator with a diode set that functions like the the one(s) on Dave's generator.
Click to expand...

Electrical befuddles me. Excuse the interruption. Like many, electricity is invisible, and cerebral. You have to imagine most of it, and I'm too visual. I get it when I seriously ponder it, but I think I speak for MANY PEOPLE LIKE ME.I'm sucking it all in, hoping something sticks.
 
The lead wire to the third brush is broken, most likely near the field coil.
If there is enough wire showing at the field coil you can repair with some solder, be sure to recover the repair using a cloth sting, never use electrical tape.
You'll have to pull the armature out to get to it.
 
If you've went this long without killing your battery, it must be charging. Put a voltmeter directly on the battery and take readings at engine off, engine idling, and then cruising RPMs. Let us know, those readings will tell the story of your actual charging condition. Could be someone rewired your ammeter and it is only inline with the accessories, instead of where it should be, inline with the battery/generator.
 
I wonder if your car might be wired wrong? Start by checking the junction box on the firewall. When you attach a battery charger to the wire on top of the starter can you see the couple of amps of charge?

Charlie Stephens
 
It could very well be wired wrong, and might've always been. I like Charlie's suggestion as a way to check it, and if it fails I'll trace wires in the junction box.
 
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