I just had a full build done, so there was alot of " putting things back together".

One thing i ahve noticed is that when i first start my car and for the first 10-15 minutes of driving, my cars interior gauge for voltage reads nice and high like it had for the last 104 k miles.
( yes its a super old alternator)

I hve a stereo system, but it uses a 10 farad cap, and the bass is very very low as my rearview mirror moves too easily at the moment to have it up very much at all.

I also notice that this issue doesnt seem dependant on the stereo even being on.


What happens is that the read out for voltage slowly gets lower and lower as i drive.

The battery connections are fairly solid..

but again, when i park it and start it up the next day, its all the way back up again..

Is this a common issue?
Does this mean a bad alternator, a bad voltage regulator? etc etc..

any help would be appreciated.. every time we have to replace something ,theres alot of FI stuff to pull off, and it just causes issues w exh leaks when we mess w it.

 

Alt or bad wiring , gets worse as it heats up

 

That's a start yes. And it does seem like a " when it heats up" thing.....just curious if anyone had similar issue and found a reason..

 

I've always wondered the same, My start up voltage is 14.4V when the car is cold, Then it starts to drop as the car warms up. Some times it gets down to 13.4 in hot days. and if i re-started the car, it will stay low.

From the FSM it should be between 14.1 to 14.7 volts.

 

Mine can get as low as 12v.

 

Only way to fix that is get a alt. made with higher amp output there are a few shops out there that go through and take them out replace diodes and stuff like that to make the higher output.

 

nah you can buy em straight up , 250 amp, those things take some serious draw off your engine tho.. i had one on my Suburban and they whine like a super charger.. the pulley ususally has a fan built in.. great.. lol.. more heat.

they are "cheap".. 220 bucks, plus about 150 to get it crammed back in there w all ym turbo stuff in the way..

i was really hoping someone would chime in and say " that happened to me after my built and it was just a crapy connection" etc etc..
lol.

Im just far past tired of spending $ on this car.
Such is life tho.

Apparently another local guy i shaving the same issue as me, they are putting in a 250 amp as well. Ill let him be the ginuea pig on whether or not ill go HOA or jsut oem/

 

sadly its a going bad alternator

 

yup, buying the 250 amp high output alternator in a week or so.

W the 0 gauge wiring and 10 farads of cap already in the car, i dont think ill ever be replacing another one in its life now. 103k on an OEM alternator is pretty damn good anyways.

 

Do a load test on your battery too. It may be getting too old to hold a good charge.

 

Nah..its brand new too.

 

Make sure you have solid grounds in the trunk and sand it down to bare metal. Also do the big 3 upgrade when you are installing the alternator. Ditch the cap and pick up a real solution like Kinetik hc600 or 800. They are also available as Stinger & Odyssey brand name .

 

I managed a 12v shop for 10 years when I was a young man..mecp certified etc.
My grounds and install are second to none and the " cap" I mentioned is.
imilar to what you posted..install is not an issue. Wiring is huge.. runs are short..etc..
My issue is not a common characteristic of an alternator w a blown diode, only reason I posted.
Since it " resets " itself when cold.. thot it needed a mention..
Lack pf previous performance wasnt a factor..s:mply the new behavior since the build

 

So, Do you think the alternator output voltage should be stable and never drops & what voltage do you guys see all the time ?