RPM just dropped

[rfkjustin]

I was cruise controlled at 75 and playing music at about 65% and my car suddenly just lost power on and off for like 25 seconds. RPM would drop to 0 or a rapid jolt. After i turned off my radio, it stopped. I have 2 amps prime 750.1 and xtr 800.4 stock alt and xs s3400. Im leaning towards my alternator being the culprit. Just wanting to get some opinions. Thanks in advance.

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[BOOMINGRANDPA 5,000+ posts]

yep sounds like it.. just make sure it don' do it when stereo is off at all.. just let advance test it, tell guy u wanta test it with stereo on for "load" test..

 

[los33 10+ year member]

I was cruise controlled at 75 and playing music at about 65% and my car suddenly just lost power on and off for like 25 seconds. RPM would drop to 0 or a rapid jolt. After i turned off my radio, it stopped. I have 2 amps prime 750.1 and xtr 800.4 stock alt and xs s3400. Im leaning towards my alternator being the culprit. Just wanting to get some opinions. Thanks in advance.

Sudden rpm drop is caused by the serpentine belt snagging the block cause it to not drive any more.
Could be a alternator getting stuck or other components getting stuck like water pump, ac compressor, power steering pump.

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[rfkjustin]

Does lack of power of the alternator part of the problem also or no?

 

[Boomin_tahoe 5,000+ posts]

Could be. Once alt fails, everything will follow....

Need to find out if alt is indeed starting to fail, then another is due. Why is it struggling?

Btw...you got audio I see you listed. Is the big 3 done yet? Is there any electrical upgrades?

 

[rfkjustin]

Could be. Once alt fails, everything will follow....
Need to find out if alt is indeed starting to fail, then another is due. Why is it struggling?

Btw...you got audio I see you listed. Is the big 3 done yet? Is there any electrical upgrades?

Ill check the voltage tomorrow and no electrical upgrades. Any reputable alternator makers? I heard ohioalts and singers are good. Thanks in advanced

 

[ChaseinBass]

Ill check the voltage tomorrow and no electrical upgrades. Any reputable alternator makers? I heard ohioalts and singers are good. Thanks in advanced

Is battery dead now ? I doubt its the alt, If it was, the battery would be dead and battery would have to have dropped voltage all the way down to where the car wont run anymore and wont charge back up again. More likely a loose battery conection maybe. I killed all three of my alts and truck ran fine but only till battery's died. I would check battery connections first and and then have it load tested. Also if its your alt you will know tomorow when you go out to start it lol !

 

[los33 10+ year member]

Does lack of power of the alternator part of the problem also or no?

Ill check the voltage tomorrow and no electrical upgrades. Any reputable alternator makers? I heard ohioalts and singers are good. Thanks in advanced

An alternator can go bad in two ways, either the regulator goes bad causing fluctuations in voltage or not charge at all.
Or it the alternator pulley section can go bad all together causing it to get stuck.

This problem can also happen from a regulator going bad in a way that's caused by clipping a amp to much or even the belt is going bad it's self.

If the regulator goes bad you will know by a dead battery.

If the pulley section is going bad you will know by removing the belt and turning the pulley by hand listening for grinding or hard to turn feeling.

A bad belt can be fixed by tensioning it more, but if it makes the tensioner max out or even get close then it's time to replace.

High rpm's with strechy belt will cause the pulley system to miss which causes loss of power also.

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[Boomin_tahoe 5,000+ posts]

So your running extra audio equipment off stock electrical? Not good man not good.

 

[ChaseinBass]

An alternator can go bad in two ways, either the regulator goes bad causing fluctuations in voltage or not charge at all.
Or it the alternator pulley section can go bad all together causing it to get stuck.

This problem can also happen from a regulator going bad in a way that's caused by clipping a amp to much or even the belt is going bad it's self.

If the regulator goes bad you will know by a dead battery.

If the pulley section is going bad you will know by removing the belt and turning the pulley by hand listening for grinding or hard to turn feeling.

A bad belt can be fixed by tensioning it more, but if it makes the tensioner max out or even get close then it's time to replace.

High rpm's with strechy belt will cause the pulley system to miss which causes loss of power also.

Sent from my N9560 using Tapatalk

Whats a pulley section that gets stuck? Or do you mean the bearings freezing up in the alt ? But either way if at is not turning its not making power so battery will be dead. not really an intermittent problem with power of vehicle going off and on ? right ? But I will agree with voltage reg sometimes causing fluxuations and such but usually they just stop turning on.

 

[los33 10+ year member]

Whats a pulley section that gets stuck? Or do you mean the bearings freezing up in the alt ? But either way if at is not turning its not making power so battery will be dead. not really an intermittent problem with power of vehicle going off and on ? right ? But I will agree with voltage reg sometimes causing fluxuations and such but usually they just stop turning on.

Lol I get tired of putting detail terms, but yes the bearing that turns to spark the stator.
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[ChaseinBass]

Lol I get tired of putting detail terms, but yes the bearing that turns to spark the stator.
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LOL just wanted to FUQ with you tonight lol !

 

[Boomin_tahoe 5,000+ posts]

I'm wondering how the gains are set on the amp....

 

[rfkjustin]

The battery is not dead. its at 13v and cranks. I measured voltage yesterday full tilt and it held 13v . Then today the fiasco of RPM just disappearing happened.

 

[ChaseinBass]

I'm wondering how the gains are set on the amp....

True but again unless alt is bad or and battery current is totally used up car should not quit. I am guessing little homie dont have any kind of voltage meter ? I am always amazed at all the peeps that have stereos with no voltage meter ? Like having a race motor with no tach ? You have no idea whats going on with it till its to late.