Stupid question: ammeter

[FISCH]

I had the Command Car out and saw at speed (35 mph) the ammeter was reading like 30. The later was new to me or I just haven't noticed. At idle it is barely on the + side. I checked the Tech Manual and didn't see it listed, but what is the normal operational reading of the ammeter?

[Ray Edsall]

G,Day fisch . It depends on the condition of the battery {whether it is flat or fully charged ] If it is a bit flat it will charge up to Full , then the regulator will cut in and the genny will not charge the battery any more ,until your battery starts to discharge . EG put the light,s on . Then the Genny will start to charge the battery . These old meter,s are not that accurate . So i wouldn,t be to worried to much . At idle there is less current being produced by the genny . As the rpm increases ,so will the amps increase . If it continues producing 30 amps all the time then you might have a problem with the regulator . Ray

[jim lee]

I've had the Amp meter peg on occasion in my WC53. Being a x-radio van, it also has a volt meter. So, you can see what the battery voltage really is. And it goes up to around 16 or so when this is happening. My take on it is that the old voltage regulator sometimes gets stuck. Then, after a bit it unsticks and everything goes back to normal. (Luckily)

-jim lee

[Andersun]

I believe the generator doesn't even provide real electricity until the engine is running around 1200 RPM (called the "cut in" speed). Then it starts helping the battery run the vehicle. It's not until 1800 to 2000 rpm, the generator can provide all the electricity. So at 35 miles per hour you should see good positive amp flow. I will have to look at my amp meter next time I take the CC out to see. The only guages I normally look at pretty much all the time are engine temperature and oil pressure.

The volt guage should only be turned on to see volts and then turned off as soon as you get a reading. Otherwise you will burn the coil out.

[Kaegi]

the lower the voltage in the battery the more amps it will show on the gauge. as the battery charge gets closer and closer to normal the amp gauge would read lower and lower till its just above zero when battery fully charged. when you turn the headlights , heater fan etc on the gauge might rise slightly as the regulator is compensating for the increase load.
Generator vehicles run off the generator not the battery so it is always putting out voltage. you can start the vehicle, pull the battery and drive across the country without issues. With alternators you cant do that. they will fry without a battery. With a gen you can compression start the truck with no battery installed. cant do that with and alt.
Jim Lee, yes your regulator is sticking. maybe get it serviced. there is a place in Ballard that can probably dial it in. I can look them up if you want
I had my 12 votl command car stick on full charge and I pulled the cable when it was running and every bulb in the truck got really bright untilthey blew! the carryall/command car gen is a powerful beast. In Europe people used them for welding after the war.

[Andersun]

Drove the command car tonight with main lights and panel lights on. At idle, the amps went to neg 10. As I started to drive, the amps kicked up to pos 10 and then slowly tapered back to pos 1 as I kept driving. When I had to stop at a traffic light, it went to neg 10 and then back up to pos 10 as i started driving. Once again as I continued to drive the amps tapered down to pos 1. Driving speeds were between 25 and 40.

[Kaegi]

I think reg is out of adjustment or maybe some dirty connections. it should never really drop below zero when running even at idle with a load

[Ray Edsall]

G,Day . Try another amp guage .Make sure that body of amp guage is well grounded . If i remember rightly there is a spring on the back of the bracket that hold ,s the meter in place . Ray

[Lang]

I am pretty sure it is normal for a generator to provide insufficient power at idle to run everything.

This was one of the main reasons the world went to alternators - charge at
idle.

The Fisch machine is perfectly normal. Nothing is wrong with the ammeter.


Lang

[Lang]

Still looking for Dodge but found this in a 1953 Buick manual.

"The generator is capable of producing sufficient continuous power at speeds over 25mph to run all systems simultaneously (lights, wipers, heater, radio)."

ie If you want to run all those things at idle you will finish up with a flat battery.

Lang

[Lang]

From the 1942 Ford Truck book.

Place the headlights on high beam. At 1575rpm ammeter should not read more than 30-33 amps.

As the engine speed is reduced a negative reading will be obtained, this should not exceed 8 amps at idle.

Increase speed and watch the regulator cut in to provide at least 30 amps by the time the motor reaches 1575rpm (the equivilent of 24mph).

Lang

[Kaegi]

I have driven gen vehicles for 100s of thousands of miles and never had a battery go dead in traffic jams in winter with everything running. Also a buick with a delco system (not quite as good as autolite but better than bosch) is not the same animal as a 12 volt 55 amp command car system. it should never read negative at an idle.

[Lang]

A battery will run the systems on a car for hours without any charge. If you are in a traffic jam, each time you creep forward you will speed the engine up to replace at least some of the charge you lost while stopped meaning you might be able to do this for days until the losses overwhelmed the replacement.

At our age we have all driven generator vehicle 100's of thousands of miles and I certainly have seen a small idle discharge, everything operating, on what seems a normal operating system in a variety of old vehicles.

I can't figure out why Buick and Ford both went to the trouble of putting in their manuals mention of a faster speed required to achieve proper charge and Ford actually mention a minus figure, if there was not something to it.

Lang

[FISCH]

Wow, great discussion.

I didn't mean to start such a thread, but it does remind me of how active the forum can be.

A couple more details... the only modern "luxury" I placed in the car. I installed a 12v auxiliary plug ( cigarette lighter) in the car. I discovered that while the car was parked and not running the kid used the plug to charge.

So figure, a 12v cell/game for two hours wouldn't drain the battery, especially since I have a original size (capacity) battery in the car ( yes, I have a forklift battery in the car). But it woul likely drain enough to where the voltage regulator would want to " top off" the battery, especially since I was running the lights, etc... while driving. So I figure that maybe everything is ok, now to worry on the transmission...ugh.

Thanks for the talk, and more Info, better.

Fisch

[Kaegi]

Lang, I agree to a point with you but if you ever drive a command car or carryall with factory 12 volt I think you would be impressed. definitely no discharge in operation. the generator weighs I think 70 lbs! ;/) also the pulley speed at idle on the WC 3/4 tons is probably a bit higher than your average auto system. kinda like the fan runs a small pulley for higher fan speed offroad