voltmeter

[ALANSD]

Just curious motorhomers- my alternator gauge has been hovering in the "black zone", below green and above red, on my latest trip. Generator has been running most of the time as well.
Curious, as the battery is up, I wonder if the alternator is having a problem, or if it is normal? I expect it to read in the 14v range while driving. So far no problems,thankfully, but I will put a check meter on it when I get a chance to stop and do so.

[FrankR]

Factory voltmeters are very poor quality. They are designed to reflect any electrical system action. There are many great gages sources available. A very monitored voltmeter can be a great tool. Volt meter fluctuations often fortell of coming problems. Most alternator failures are caused by poor battery connections and meter gyrations.. Either the battery clamps are loose, corroded or both. The altenator cannot adjust for full current output with bad battery connections. This action collapses the field energy and the coils usually fail and have an "open".. Poor battery and system grounds connections also contribute to early electrical failures. It is a wise person who installs a new and seperate ground to the trailer from the battery ground connection. Ground connections are often undersize and not considered. There is no such thing as too many or too large grounds.

[thenewkid64]

Alan,

I recently had a new alternator installed on my MH due to the same symptoms. I also installed a volt meter in addition to the factory dumb dumb gauge. The aftermarket one shows much more detail in what is going on. It even deflects when the turn singals are blinking. I have it tied ito the main fuse block and is only on when I have the key in the on position. Running the MH down the road it seems to hover in the 14 volt range, even at night with all the lights on. I have also re wired my battery connections and have new batteries so I expect it to all work as designed. If I were you I would do the low cost stuff first. Check the battery connections and get a $15.00 automotive volt meter and install. Good luck

[FrankR]

I would strongly recommend an after market volt meter that costs at least $35. For a little more money.......about $60 ya can get a digital voltmeter. Many solar products have the digital meters for sale.
A properly adjusted voltage regulator will compensate and adjust for any induced amps load. This is true for internal and external regulators. Lites should not dim at nite. Some serious sound or lite systems can drag down a large altenator..

[PeterH-350LE]

There is only one thing better than a voltmeter:
that is two; one for the motor and one for the coach batteries.
For 12V fridge drivers like me, a coach battery voltmeter is a must to have.

[FrankR]

It is great to be able to monitor several battery banks, but 2 meters are not necessary with a motor home. With the big bus rigs, it is common to have just a single volt meter that is connected to a rotary switch that is connected to start batteries, coach [house], and solar-inverter bank. While cruising down the hiway, the status is observed of any bank. Many good changing systems are connected so as to afford the opportunity to pump power to any battery bank being used. Many rigs use the rood airconditioning powered by a large inverter thru a battery bank. It is silent and some what free. Hi amp solenoids wired creatively can be made to control the complete charge system. It is a great help in some cases to be able to turn off the alternator going up a long steep hill.
Usually the best time to observe battery conditions is as they are exercised. Oh, OK I do some times place volt meters near the battery banks for a quick test. These meters are connected with a rotary switch and a push button switch. Yep, our temp gage is also wired thru a rotary. Same gage can reflect the temps of engine water, oil, auto trans, engine compartment and outside ambient. Of course it is a digital gage....

[ALANSD]

thanks for the input as usual guys. My voltmeter does dip a bit as the flashers flash, and I guess it is working ok. I checked the battery connections before this trip i am on, as a routine. The terminlas are clean, as that is part of my maintenance as well. I do the deal with baking soda and all on all my vehicles.
I expect that the alternator may be a problem, but as I am on the "road" I will watch it and see what happens, The batteries are all "up" with no loss of charge at this point. I thought maybe when running the generator the alternator just did not charge at the level it would otherwise.

[thenewkid64]

Alan,

One more piece of food for thought is that the standard Chevy P30/454 alternator is a 63 AMP model. This may not meet your charging needs if you have depleted battries etc, or even a minor loss of output could affect you as it is so low to start with. I do not know if AS installed a HO atlernator, but I doubt it.

[winner]

with reference to my l987 Airstream 345, the alternator was faulty on this motorhome when I purchased it - I recently had it re-built. It is the original 105 amp alternator installed by Airstream. It is now working fine, It is putting out 15 V at the shaft, but my dash meter is only showing 13+. So it is reasonable to assume that dash voltmeters are inaccurate to some degree.

[ALANSD]

Well, we are now in our 6th state on our trip Nor th and back. All has been fine, other than the alternator business. The voltmeter got progressively lower, and the coach runs fine, but the battery is pretty well dead. I start it off the coach batteries. I will take it to a chevrolet dealer here in VA, my sister is an administrator there.....check the battery and alternator, before I install a new one of either or both.
The trip has been fabulous so far-----although a bit warm in the drivers seat with only the roof air on and outside temp of 95+.
Other than that we are having a blast!!
Oh- we have not seen one other Airstream Classic since we left home 12 days ago.Did see two trailers and one newer AS coach.

[ALANSD]

new info on the above---my battery isolator was shorted out. I replaced the alternator, and still got no reading at the battery. I checked voltage at the alternator it was putting out 28volts...sum of the batteries still alive at the rear. I replaced the isolator with a new one from Pep Boys, same brand as what was on mine, and all is fine. Reading 14+ volts and gauge in the green. Now we drive on towards the south again......