The Stovebolt Site Forums The Shop Area The Electrical Bay 6v alternator on 1954 truck - will gauge be OK?

I will be changing from an original 40amp 6v generator to a higher amperage 6v alternator (1 wire) in my 1954 Suburban. I have used a 60 amp 12v 1-wire alternator through the original ammeter (years ago - no problems)

There was a 55amp optional 6v generator that year.

How high an amperage (at 6v) can pass through the original ammeter with hurting it? This 6v alternator may produce max 70-75 amps, with 60 amps at idle.

Right after starting, you'll probably see the ammeter peg out for a short time from the alternator replenishing the starter load. It probably won't hurt the ammeter, but if you're concerned about possible damage put a shunt between the ammeter terminals. A piece of moderate-resistance stainless steel such as the solid portion of a worm-drive radiator hose clamp can be formed into a horseshoe-shaped shunt. (Shape it like the "ohms" icon on an electrical diagram) Drill holes in the ends of the shunt so they will fit between the studs on the back of the ammeter. Most of the charge current will bypass the ammeter, and there will be enough flow through the meter to deflect the needle in the "charge" and "discharge" direction. The ammeter is very inaccurate to begin with, so it doesn't need to indicate actual current flow.
Jerry

Just curious.
What is the reason/benefits for the change?
Where can a person purchase a 6v alternator?
I assume the 6v alternator looks just like the factory 1954 6v generator.
When replacing the original 6v generator with a 6v alternator are there any other electrical components that need to be up graded?
Other than possibly adding a shunt on the ammeter.

Thanks,

Thanks for the advice. I will wire like this illustration, unless someone wants to caution me or advise me otherwise.

jorb,

I do not want to admit what it cost - I came into some unexpected money and I have reached a point where I can splurge every so often.

Also, I'll be carrying the old generator and voltage regulator as "spare parts" when I drive to places like Springfield, MO this summer. I usually carry a spare starter, generator, carburetor, and distributor.

Tim I've bought a '50 (will be delivered first of next week ) with a 12 volt battery , and the old style generator , I've got a spare 12v alternator . will the gen. or the alt. be best ....

I seen in TIPS where the amp meter was changed to a volt meter , I did this And it works great ..In the tips he had put a volt face on his I just left the amp face..cost under $20 . I think all the newer autos have a volt meter ....

Tim, if you follow that diagram, the ammeter will never show a charge- - - -it's bypassed before the charge current gets to it. If you want the ammeter to function normally, just run the output of the alternator to the BAT terminal of the regulator and isolate (tape) the ARM and FLD wires at both ends. There's no real need to remove the regulator if you want to retain a stock-appearing look. Just be sure the wire from the BAT terminal to the ammeter is heavy enough to carry the alternator output- - - -I'd recommend #8 wire, with the same size wire from the ammeter to the battery cable terminal at the starter. Your ammeter and all the accessory circuits will operate as original, and you can do the shunt thing if you're concerned about excessive deflection of the ammeter.
Jerry

Jerry,

As always, Thank You.

What you describe is how I wired the other 1-wire alternator I used several years ago. It worked fine.

For this installation, I will do some hiding/stealthiness/fake-out with a gutted voltage regulator (that's why I'll carry a spare working/tested voltage regulator). This idea (and photo, above) came from a GMC friend, Bill Miles, who is using a similar 6v positive ground 1-wire alternator on his 1953 GMC Hydra-Matic pickup.

I'll post photos of my installation - it might be a few weeks from now.

wanderer1955 1st,

I think your 12v generator delivers more amperage at low RPMs than does my 6v generator. My 6 volt generator gives out low amperage at low RPM and this results in dimmed light at night. This 6v alternator is not a necessity; it is a luxury, but I will have brighter lights at night, especially at idle.

Tim, I can't say it was the higher current output that did my ammeter in but after a few months with my one wire 6v alternator I noticed my ammeter was showing a discharge any time there was a draw (headlights, brake light, even turning the dome light on). A check with my multimeter showed a good solid charge even when the ammeter showed a discharge. I eventually put a 6v voltmeter under the dash because my original ammeter was toast. It could have just been a coincidence or it could have been the alternator pushing 60 amps through it for an extended time after a rough hot restart. I have an NOS ammeter to replace it if I ever decide to go back to the generator.

The 12V alternator in my burb pegs the original ammeter on start up and sometimes hangs there until I thump it but it has not damaged the meter. I say use it as is.