Altenator Issue?

[Roushinator]

Tell me what you think about this issue.

95 5.0 engine. Car starts and runs great. When I slow down and come to a stop the car idles around 1k or less but the volts go down to 8 (range is 8-18) and then it acts like it wants to die and sometimes it does. Even when i give it some gas or while driving the volts still stay around 8-10. BTW This was a problem before the heater core incident.

I am thinking my Altenator is dead. What do you think?

[360Rocket]

get a multimeter and check battery voltage not running, below 10 volts the battery is done.

Check voltage while engine is running, you need close to if not 14 volts no matter the load you add by turning on lights, stereo, a/c etc.

I just went thru this 2 weeks ago.

[Roushinator]

Originally Posted by 360Rocket

get a multimeter and check battery voltage not running, below 10 volts the battery is done.

Check voltage while engine is running, you need close to if not 14 volts no matter the load you add by turning on lights, stereo, a/c etc.

I just went thru this 2 weeks ago.

Yeah i remember. So while running i need around 14 volts? Do I check that on the battery terminals or on the altenator? If less then the altenator is bad?

[vista blue]

Sounds like it to me.How old is the battery? Could be voltage regulator.Well any ways hope you find problem.HAVE GOOD ONE.

[spindlecone]

Ck it at the alt, should be minimum 13.5 volts.at idle 8/9hun rpm

[360Rocket]

Originally Posted by Roushinator

Yeah i remember. So while running i need around 14 volts? Do I check that on the battery terminals or on the altenator? If less then the altenator is bad?

you can check it at the battery terminals, same volyage reading as the alternator output. Mine read 13.5 volts and was still bad, a sign that the diode is going bad. You can run it that way, but it will leave you stranded eventually.

[Roushinator]

I will check tommorrow and post the results. Thanks.

[Roushinator]

So i checked while it was not running at the battery 11.99 volts. While running at the battery 14.69v. Voltmeter (in car) in dead middle.

But it always idles great when i first start it. It is when i drive for a while it starts acting up. Could it be that the altenator starts to fail as it heats up. I guess i need to drive i t a bit tommorrow and check.

[360Rocket]

could be some type of fuel vapor lock, or a dirty air sensor, or MAF going bad too. I hate chasing this crap. Alt & battery sound good.

[vista blue]

Does it still run if you take positive cable off? I've tested my alternator before that way if it dies it's bad. HAVE GOOD ONE.

[Mariob01GT]

Easiest way to check the alternator is to fire up the car and disconnect the battery. It should stay running on the alternator only, if it doesn't then your alternator is a likely culprit. Also if it reads 14volts that means it's somewhat okay, doesn't necessarily rule it out but you might have to look elsewhere.


Usually with a bad alternator, your volt needle will be jumping all over the place. Eventually the alternator dies while your driving in the middle of nowhere, the car runs on the battery when your doing 55mph and a semi on your ass. You start noticing the lights and dash going dim cause it's 1am in the morning and your brain finally starts working again "damn..... i should have changed that alternator last week.. son of a bitch". So of course the lights get dim and dim and it's barely running and you end up coasting it off on the next exit only to find out your in the middle of nowhere and on a friday night at 1am the damn tow trucks are busy as heck. No not that it ever happenned to me.

[Roushinator]

Well the other day i ran it around for 30 minutes. When it first started it was around 14.69 after 30 minutes of driving it was around 13.8. I could not get it to replicate the problem from before (8v). My theory is a bad voltage regulator. But i will keep driving and when it acts up then take the measurements.

[wavgby]

I have been reading these, nd tonight on the way home my battery light came on, I made it from tampa to home and had no problems, I have a smell under the hood like melting plastic. My volt meter on the dash never waiverd any suggestions? Oh yeah 1 more question, is the alternator anything special or can I buy a gt one...why is it that everything seems to be breaking at the same time?

[JR'S STAGE2]

Originally Posted by wavgby

I have been reading these, nd tonight on the way home my battery light came on, I made it from tampa to home and had no problems, I have a smell under the hood like melting plastic. My volt meter on the dash never waiverd any suggestions? Oh yeah 1 more question, is the alternator anything special or can I buy a gt one...why is it that everything seems to be breaking at the same time?

If you have a stage 3 it is different than a Gt one. The housing is different and it is clocked different also.

[wavgby]

Originally Posted by JR'S STAGE2

If you have a stage 3 it is different than a Gt one. The housing is different and it is clocked different also.

ummm where do you get it?

[JR'S STAGE2]

See if Bill or Ethan at stage3 can get it. If they can't I know Hillbank Motorsports can.