Alt over charging...

[jroddsm]

So my alt. is charging at 15.5v. I took it off and had it checked at two different places and it was good. Charging at 14.2v steady. So why would it be so high in my car which is a 95 gsx?

 

[RocCitySlayer]

So my alt. is charging at 15.5v. I took it off and had it checked at two different places and it was good. Charging at 14.2v steady. So why would it be so high in my car which is a 95 gsx?

Mine charges at 13.5, Id rather have one that charges like yours

 

[LiquidX]

Over charging can damage electronics. I'm not sure if that's too high but that's a possible failing voltage regulator.

Just FYI I've had bad alternators pass the tests since they only failed when hot.

If it's an Autozone alt, I'd get it replaced and have the one off the shelf tested as well as I've had some fail off the shelf.

 

[RamenPride]

Yeah sounds like a bad/dying voltage regulator. Time for a new alternator.

 

[DSMnoobsause]

also have your battery tested to make sure the alt isnt trying to charge a half dead battery.

 

[1gslotsi]

Definitely leaning torwards bad regulator as mentioned before when it gets hot it will cause Tue problem rather than cold the bad battery would cause it to charge at maximum voltage like 14.2 or 14.5 the regulator is what would explain the increase in maximum voltage

 

[DSMnoobsause]

it would be careless to not check the battery.

 

[dsmboost84]

I had the same problem last summer. Turned out to be the voltage regulator, so I replaced the alt and it was back to normal. Hope this helps

 

[Lou98GSX]

if the battery is weak the alternator is going to try to bring the voltage to where it belongs so you will see a higher reading . try hooking the meter back on and rev the motor to see if the voltage goes higher than 15.5v it shouldn't .

 

[NeMiZiS]

Probably a bad alternator.
My alt when out on my 420A and bought a new one from the auto part store.
It was charging at 19.00+ volts, right out of the box.
Swapped in another alternator and it was all good.
Damn thing is I couldn't return it as "bad", because when they test it at the store it tested "good".
Only wish I would have figured it out before I replaced the ECU!
(The voltage regulator is inside the ECU on a 420A.)

 

[jukebois]

check for corroded electrical connectors.check for oil or power steering fluid dripping inside your alternator.

 

[mattasi]

All good answers so far. The regulator is going out. I had an overcharging problem once, I noticed it in ECM link my voltage would range from 12.8V up to 17.1V, and just keep doing that cycle. OK well my turbo timer that shows voltage just said like 14V and never changed to much, not like ECM link was. So I took my overcharging rebuild alternator back to the starter/alternator shop I had rebuild it and they confermed the overcharging problem. If I didn't have ECM link I would have never known I had an overcharging problem. Well untill I fried something... Anyways mine was a voltage regulator, cost 60 bucks for them to change out, voltage stays perfect now.

 

[red1993gsallmt]

I blew my headlights out due to a bad regulator years ago, I rememeber ripping it at night and seeing my headlights get real bright then pop! Out went the lights, looked at my logger and voltage spiked to 17+ volts. It was a bad reg in the alternator.

 

[Anubis_4_99]

I blew my headlights out due to a bad regulator years ago, I rememeber ripping it at night and seeing my headlights get real bright then pop! Out went the lights, looked at my logger and voltage spiked to 17+ volts. It was a bad reg in the alternator.

That's exactly what happened to mine, but my problem was actually inside my wiring harness. I could get it to overcharge by wiggling the wires between the intake and the valve cover .

I agree with most the other posts here, get both your battery and your alt checked, and also make sure to check all your connections and grounds. I've had some funky issues from a bad ground.

 

[jroddsm]

Ok thanks guys! All good stuff!!! I did find it. The plug that goes into the alt had a broken lock so it would come loose and wasn't able to regulate the voltage. Now I have to figure out where to get a plug or how to keep it plugged in . Thanks again.

 

[Anubis_4_99]

Ok thanks guys! All good stuff!!! I did find it. The plug that goes into the alt had a broken lock so it would come loose and wasn't able to regulate the voltage. Now I have to figure out where to get a plug or how to keep it plugged in . Thanks again.

some parts stores carry misc plugs/pigtails. Worth a shot just incase.

Otherwise your probably looking at a part out or junkyard, or something online like e-bay or rockauto would likely have it.

 

[mattasi]

Nice, glad you figured it out. Yea I agree if you look for a part out ad from someone on here, or a yard will have that no doubt. Ta.ke your old plug with you.

 

[LiquidX]

You can also contact GaryMitsu or Stangmurdera for the plug.