battery or alternator failing?

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diymirage

diymirage

HP@idle > hondaHP@redline
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this is on my plow truck
it has a volt meter which used to stay pretty steady at 13-14

today i was out plowing and it looked liked the voltage on the gauge dropped way more then usual when i run the hydraulics, down to 8

what really caught my attention is that it takes longer and longer to get back up to 13-14 and by the time i went home it was only at 10, very slowly creeping up to 11

i tried measuring it with my little harbor freight volt meter and im not sure what to make of the readings
it climbed real slow from 0 to 16 to pop, and my wires started smoking

so, that test is out of the question

so, what are you guys's thoughts?
 
This is where an ammeter is useful. But you don't have, nor a carbon pile, so lets move on.
My first guess is the alternator. here's why
The voltmeter, wherever it is wired should show system voltage.
The alternator is regulated to provide 14 Volts (or so) to the system.
Even if the alternator could not keep up with the power demands of the plow work and started using battery, when done with the plow, the voltage should come right back up to 14 volts.

If you have a handheld voltmeter you can check the voltage at the alternator output and at the battery. it should be the same at bpoth if the engine is running or if it is off. That will show if there are voltage drops (loose connections) that might make the inside gage readings misleading
 
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Curious,... what drives your pump for the hydraulics? Electric? Could it be that is drawing a lot more power than before?
 
Mattax said:
Even if the alternator could not keep up with the power demands of the plow work and started using battery, when done with the plow, the voltage should come right back up to 14 volts.
Click to expand...
Jump the regulator to be sure that's not failed. if the alternator has a ground regulated side - then ground that terminal or wire from the tieminal/
Regardless, recharge the battery using a slow charger. Otherise there's a good chance of cooking something when you do get the alternator going again.
 
diymirage said:
this is on my plow truck
it has a volt meter which used to stay pretty steady at 13-14

today i was out plowing and it looked liked the voltage on the gauge dropped way more then usual when i run the hydraulics, down to 8

what really caught my attention is that it takes longer and longer to get back up to 13-14 and by the time i went home it was only at 10, very slowly creeping up to 11

i tried measuring it with my little harbor freight volt meter and im not sure what to make of the readings
it climbed real slow from 0 to 16 to pop, and my wires started smoking

so, that test is out of the question

so, what are you guys's thoughts?
Click to expand...
Loose belt.
 
ok, i remembered i had a digital oil pressure gauge that defaults to volts when there is no signal to the wire, so i used that as a gauge

the battery shows 12.0 with the engine off
12.6 with it idling, and 12.8 with it revving

i tightened the belt and that didnt seem to do much, it did not change the readings

just to be sure, i hooked it up to a trickle charger
 
diymirage said:
ok, i remembered i had a digital oil pressure gauge that defaults to volts when there is no signal to the wire, so i used that as a gauge

the battery shows 12.0 with the engine off
12.6 with it idling, and 12.8 with it revving

i tightened the belt and that didnt seem to do much, it did not change the readings

just to be sure, i hooked it up to a trickle charger
Click to expand...
Do you have any test equipment or a multimeter?
 
toolmanmike said:
Do you have any test equipment or a multimeter?
Click to expand...
i had a multimeter but that one gave a weird readout, and then fried the wires
not sure if it was no good to begin with, if i wired it up wrong, or if it still might be operational
 
diymirage said:
just to be sure, i hooked it up to a trickle charger
Click to expand...

After the battery has charged, try working the plow with the truck running.

Do you get the same symptoms immediately?

IF you don't, the alternator may not be big enough to compensate for the plow draw.

Did you notice the plow working slower when the volts dropped?

One other thing you might check is the power/controller connections on the plow unit. Be sure they are all clean and tight.

How old is the battery?
 
Bad Sport said:
After the battery has charged, try working the plow with the truck running.

Do you get the same symptoms immediately?

IF you don't, the alternator may not be big enough to compensate for the plow draw.

Did you notice the plow working slower when the volts dropped?

One other thing you might check is the power/controller connections on the plow unit. Be sure they are all clean and tight.

How old is the battery?
Click to expand...


ill check for a date when i got unplug it in a few hours, the battery came with the truck, so i'd say at least 2 years

i did not notice the plow operating slower, BUT i did notice that the lift solenoid seemed to stick a few times
(it would not lift untill after i tapped the solenoid a few times)
 
A Old school trick my Dad taught me is after charging battery if it is vented, take the covers off and watch the cells as someone cranks the engine over (You might need to ground out your coil wire so it doesn't start) If any cell starts to boil immediately the cell is going bad and battery is on the way out .
 
I'm going alternator.

I've jumped a dead battery and once the car starts it will read charging on the gauge
 
Bad Sport said:
Go through all of the connections while the battery is charging.

What plow are you running, and don't tell me a yellow one, lol. :lol:
Click to expand...

i actually painted it red last summer
its a meier 7 1/5 foot with a monarch pump (the kind that mounts under the hood, not on the plow frame)
 
roccodart440 said:
I'm going alternator.

I've jumped a dead battery and once the car starts it will read charging on the gauge
Click to expand...
Except in this case there's no ammeter so its harder to know if its charging or not.
It does seem like its alternator or wiring. If its 12.6 to 12.8 measured at the battery, 10-11 Volts on the gage, the question remaining is what's the voltage at the alternator output.
 
diymirage said:
yes, the hydraulics are ran by an electrical pump
i dont see why they would draw more, nothing else changed
Click to expand...

You've never had a starter going bad and draws excessive amps to run it? Electric motors can develop issues that cause them to draw huge amounts of amps. Just a thought. Might be worth disconnecting the hydraulic pump motor and see if it still happens.
 
Old school trick here when it is running disconnect the ground wire from the battery if it dies the charging circuit is bad if it stays running its the battery.
 
Alternator.
I had one that charged,barely.
With the plow it wouldnt keep up.
Threw in another alt and it was fine. Mind you, i have a pile of spare alterntors.
 
I suspect you had your meter connection in the amp test socket, and thats why the wires melted.
Ohms and volts on one socket, amps on the other.
 
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