Is Something Wrong With Alt?

[Crownvicon28s 10+ year member]

My voltage starts out at 14.1 to 14.4, when I turn my lights on it goes down .3 volts. then as i drive it steadly goes down and sets around 13.5 with no music on. Is something wrong with my alternator? I was thinking a MLA module would solve my problem but Im not sure. Shoud I upgrade my Big 3 wires to 0 gauge. Would this make a difference in my voltage?

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[dman4486 5,000+ posts]

is it a factory alt? if yes, go have it load tested.

 

[BoxdGM 10+ year member]

does yours have the 90amp or 130amp? the police models have the bigger one. mine had the 90 but i bought a 130a one from checker auto parts for like 125.00

edit just saw it said 200amp nevermind

 

[Crownvicon28s 10+ year member]

is it a factory alt? if yes, go have it load tested.

Its a rewound stock alt. Figured you sacrafice voltage for amps but this voltage seems a little too low.

 

[dman4486 5,000+ posts]

Its a rewound stock alt. Figured you sacrafice voltage for amps but this voltage seems a little too low.

too low would be anything below what resting voltage is for your battery.

for me it would be 12

 

[Crownvicon28s 10+ year member]

too low would be anything below what resting voltage is for your battery.
for me it would be 12

So 13.5 resting volts is fine without any accessories on? Just thought my voltage should be a lil higher. When I only play my mid and high amp voltage drops to 13.2 on peaks. How do I get my amps to see 14.0 volts or higher? Don't know if clarification is needed but this is with the car on and driving.

 

[Crownvicon28s 10+ year member]

bump

 

[zack39648 10+ year member]

im haveing the same problem mine used to stay at 14.4-14.5 now it sits at arounf 13.5-13.9 with no music on when i turn it up im seeing voltage drops down to 12.8-13.1 ....

 

[Crownvicon28s 10+ year member]

im haveing the same problem mine used to stay at 14.4-14.5 now it sits at arounf 13.5-13.9 with no music on when i turn it up im seeing voltage drops down to 12.8-13.1 ....

Whats you setup? What kind of car? How do you plan on fixing this problem? I'm thinking about a MLA module if my alt is fine. Just want to make sure its fine first because if its not I know this module will probably burn it out.

 

[MECHMAN 10+ year member]

Most re-wound stock alternators just have a different stator swapped into them. This increases high RPM output, but DECREASES low RPM output from stock! Low voltage is simply a symptom of low amperage.

The alternator is just coming to temperature, and loosing all of it's output ability at idle. That's why the voltage comes up when you rev it up. If you had a well built alternator (a-hem) you would have MORE ouput at idle than stock. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif PM me if you need any more info.

 

[DBBOOM 10+ year member]

My voltage starts out at 14.1 to 14.4' date=' when I turn my lights on it goes down .3 volts. then as i drive it steadly goes down and sets around 13.5 with no music on. Is something wrong with my alternator? I was thinking a MLA module would solve my problem but Im not sure. Shoud I upgrade my Big 3 wires to 0 gauge. Would this make a difference in my voltage?[/quote']
What RPM is your engine at when cruising? With the tire/wheel combo you have i bet your not seeing alot of RPM at speed, that can also cause a lower output from the alternator. But it still doesnt explain your issue at idle.

 

[Crownvicon28s 10+ year member]

Most re-wound stock alternators just have a different stator swapped into them. This increases high RPM output, but DECREASES low RPM output from stock! Low voltage is simply a symptom of low amperage.
The alternator is just coming to temperature, and loosing all of it's output ability at idle. That's why the voltage comes up when you rev it up. If you had a well built alternator (a-hem) you would have MORE ouput at idle than stock. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif PM me if you need any more info.

Im not worried about output at idle. Im wondering why my voltage starts out high and trickles down as I drive and stay there when I park.

 

[frdfandc 10+ year member]

Im not worried about output at idle. Im wondering why my voltage starts out high and trickles down as I drive and stay there when I park.

Basically its normal operation of the voltage regulator. Upon first start up, the alternator needs to recharge the battery that just expended energy to start up your vehicle. Then the voltage regulator acts as an electrical traffic cop to control alternator output. It senses when the batteries need recharging, or when the vehicles electrical needs increase, and adjusts the alternators output accordingly.

 

[sexiewasd 10+ year member]

My alts put out 13.7 max in the summer after the car heats up, in the winter it starts at 14.5 and goes up to 14.7 after driving. It might be a heat related issue.

 

[Crownvicon28s 10+ year member]

So is there a way to make my amps see 14.4 volts on a consistent basis?