Voltage fluxuation

[Bigassfireman]

Ok, kind of a vehicle mechanical question but it is tied in with my lights and siren so here goes:


I noticed yesterday that my voltage meter in my pick up now jumps when anything is turned on. Today, it ticks with the turn signal. I'm getting about 15 maybe 16V with radio, heater, siren on not running and it drops to about 14 when the turn signal lights. No problems starting. Any ideas, suggestions. I'd hate to burn up any lights or my siren.

 

[Ben E.]

How old is your battery? I had a 7 year old battery in my Expedition that would start fine right up until about a week before it's very quick death. If you've got a battery going bad, the alternator and voltage regulator could have a hard time deciphering when to send power to your electrical accessories and when to send it to your battery. I'd have your battery tested before anything since that's the easiest thing to replace.

 

[WireKing]

Anything above 14.5 volts could damage everything! Ben is right. Have the electrical system checked out asap. If the battery is kaput, the alternator could start freaking out. Also, a bad alt will kill a battery too. If your running nearly 16v at idle, I'd say something is seriously wrong with your alt. Maybe a bad diode or rectifier.

 

[Jarred J.]

+1.0

 

[Bigassfireman]

Ok, thanks all! I will get it checked after Christmas, it can sit until then. My battery is only about 4 or 5 years old, I'll have to double check the date though. I replaced an alternator about 6 years ago.

 

[EVModules]

Before you go jumping off a cliff, check with a true voltmeter (vmm). Vehicle gauges are typically not accurate!


It is usually not uncommon on older vehicles for the vehicle gauge to fluctuate. If it's a newer vehicle, I'd check the battery connections (clean them while you're at it) and try it again.

 

[911tecnologies]

Before you go jumping off a cliff, check with a true voltmeter (vmm). Vehicle gauges are typically not accurate!

It is usually not uncommon on older vehicles for the vehicle gauge to fluctuate. If it's a newer vehicle, I'd check the battery connections (clean them while you're at it) and try it again.

I completly agree. Check the out put at the altenator charging post. Then Check to make sure that the battery is good. Chances are its probably the stepper motor in the clusters gauge, and the altenator is not truly putting out 16v at idle, and if the fluctuation is happing in conjunction with the turn signal it would further lead me to belive that it is the cluster.