Voltometer Dipped -Troubleshoot?

[prossett]

What exactly does the voltometer measure? It's the 12V flow of which circuit: battery - alternator - battery?

My 83 Jimmy, after a man-made MudFest (had to excavate and pour water tankers since we live in the friggin desert!) voltometer has dipped from its usual full 13 down to around 11, and my horns quit. Other than that all checks out fine.

Where would you start troubleshooting a lower-than usual Voltometer reading?

 

[Roz]

it measure what is in the circt. if the battry is diconected then just batt (V). if it is running and batt is connected, it is the output of the alt. i would say mess with the wires. check resistance to ground to see if u shorted any +leads to ground.
my main leads off the starter to fuse block shorted to engine so i had that same issue.
could be the alt though, if u diconnect it while runnin u can get a (V) reading. if it is 14-18v u should be good

 

[2Dogs]

What exactly does the voltometer measure? It's the 12V flow of which circuit: battery - alternator - battery?

My 83 Jimmy, after a man-made MudFest (had to excavate and pour water tankers since we live in the friggin desert!) voltometer has dipped from its usual full 13 down to around 11, and my horns quit. Other than that all checks out fine.

Where would you start troubleshooting a lower-than usual Voltometer reading?

Mine did that when 1 of the 3 diodes (???) in the alternator died - showing low voltage that gave a weak charge.

Maybe your horns are co-inky-dink. Check the fuses...?

 

[prossett]

Just to give some closure - a buddy said that one way to check the alternator is to disconnect the battery while the engine is running: if it dies, the alternator's gone.

I tried that and the engine died, so I'll be taking it in to test the alternator, and then I guess replace it.

 

[diesel4me]

No!!..

That WILL tell you if its charging--it'll stall if it isn't, when you pull the cable off the battery...however,it CAN also pop the diode trio in the alternator,or do other damage, by running it in an "open circut" with no battery to charge!..its a crude "test" at best...use a voltmeter next time,it might save a good alternator from an early grave...