Car Voltage help!

[PlymouthScamp71 10+ year member]

Ok I replaced my head unit to a sony explode, added a sealed battery, and ran 4 awg power wire from the front to the beck and a foot long 4 awg ground for the second. I still have te problem of my amp going into protection mode. I bought a volt metter and my car off it reads around 12.30ish car on it reads 14.50ish (both batterys read the same). Now when the car is reved it jumps to 17+ volts.. my alt is a 75 amp 50% duty alternator I know I need a 100% duty one but is there anything else I could do? right now I have to run my lights and heater and over 25 mph it does to many volt and it shuts off my amp AND head unit...

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[mylows10 5,000+ posts]

re[place the alt ,or see if you can get a external voltage reg for it

 

[PlymouthScamp71 10+ year member]

re[place the alt ,or see if you can get a external voltage reg for it

Can you give me a more general perspective of what kind of external volt reg I'll need?

 

[mylows10 5,000+ posts]

Can you give me a more general perspective of what kind of external volt reg I'll need?

well you need to find out if your alt can use an external reg or not .the alt maybe bad if its a 12 volt alt tho .,but more than likely its a 16 volt alt.

 

[PlymouthScamp71 10+ year member]

what would a 16 volt alt read? I just replaced it this fall so I know its not that. and I checked my car and it has an external volt regulator on the firewall but my cars 42 years old and the regulator looks in bad shape.

 

[Phoenix Risen 10+ year member]

it could be an issue with the regulator, you shouldnt have that big of a spike when you start driving, what kind of car is it?

 

[PlymouthScamp71 10+ year member]

it could be an issue with the regulator, you shouldnt have that big of a spike when you start driving, what kind of car is it?

I have a 1971 Plymouth Scamp. Its the Chrysler A body the same Body style used for the Dodge dart.

 

[Phoenix Risen 10+ year member]

ok, especially with the age of it it could very well be that regulator. or if thats just how that car is supposed to work you could look into a voltage stepdown and run the audio off of that.

 

[bgowdy 5,000+ posts]

****.... when you drive it goes to 17+volts? wouldnt that blow all of the cars accessories and what not?

 

[WhyUmad 10+ year member]

Alternator is bad, needs to be replaced or repaired. The voltage regulator is blown it should never go higher than 14.x voltage. Fix it before it damages more electrical parts

 

[Phoenix Risen 10+ year member]

****.... when you drive it goes to 17+volts? wouldnt that blow all of the cars accessories and what not?

its a 71 it doesnt have accessories...

 

[bgowdy 5,000+ posts]

its a 71 it doesnt have accessories...

i was meaning like lights and stuff like that

 

[Phoenix Risen 10+ year member]

i was meaning like lights and stuff like that

i know, i was just being an a$$, but lights are typically pretty forgiving with stuff like that.

 

[bgowdy 5,000+ posts]

i know, i was just being an a$$, but lights are typically pretty forgiving with stuff like that.

sh1t.... i was charging my truck and wasnt paying attention to the setting turned on the charger to like 16.5v and shot the light under my hood lol....

 

[Phoenix Risen 10+ year member]

****, depends on the light i guess.