Alternator light / Power steering whine / Belt noise

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

2004XLT

Full Access Members
Joined
Sep 26, 2014
Posts
324
Reaction score
19
Location
CT
I have a 2004 4.6 118,000 miles, battery light has been on for about 2,000 miles - P0620 generator conditions circuit. My headlights and interior dash lights flicker sometimes. I also have a noise coming from the front of the engine that sounds like a bad bearing in one of the pulleys. Most of the time when I turn the wheel I get a slight whining noise. I thought power steering pump, but I was watching a youtube video which explained that this noise could be caused by the idler pulley and tensioner going bad.

So the question is, could the alternator light and whining noise both be caused by the idler pulley and tensioner being shot?
 

GAINMOB

Supporting Member
Supporting Member
Joined
May 19, 2010
Posts
14,561
Reaction score
887
Location
Hampton, VA
possible but i would rule out the alt by getting it tested and if its the original...its due to go out...its 10 yrs old
 
OP
OP
2004XLT

2004XLT

Full Access Members
Joined
Sep 26, 2014
Posts
324
Reaction score
19
Location
CT
Alt has 'refurbished' stamped on it, gonna take to autozone for test, will they do it with installed or would I have to take it out?

Also is it possible the bearings for the fan are shot?
 

stamp11127

Full Access Members
Joined
Mar 10, 2012
Posts
6,218
Reaction score
1,250
Location
Temple, Georgia
When you take it in to be tested look and see if their tester indicates the output amperage of the alternator and if it checks for AC ripple current.
Taking it in to them is called a bench test, used to test max output amperage and voltage waveform.
In vehicle test can do the same thing but also tests the harness and connections.
The in vehicle test is usually done first, if a failure is suspected the bench test is used to verify the alternators condition.
 
Last edited:

1955moose

Full Access Members
Joined
Nov 23, 2014
Posts
5,981
Reaction score
1,336
I used to work for Kragen years back, we had a portable tester that could test alternator and starter as well as battery on car. If you suspect belt tens hoist or alternator bearing. Disconnect belt, spin both of them as well as power steering. If it sounds like a worn out dry roller skate replace it.
 
OP
OP
2004XLT

2004XLT

Full Access Members
Joined
Sep 26, 2014
Posts
324
Reaction score
19
Location
CT
Sounds good, I'll get the alternator tested and pull the belt off to check the bearings. Has anyone heard of bearings being so far gone that they cause symptoms of a bad alternator?
 

stamp11127

Full Access Members
Joined
Mar 10, 2012
Posts
6,218
Reaction score
1,250
Location
Temple, Georgia
If the bearings are that bad it will usually take out the rotor and/or stator windings. Once the serp belt is off you can spin the pulley. Anything other than a smooth spin is an issue.
 
Last edited:
OP
OP
2004XLT

2004XLT

Full Access Members
Joined
Sep 26, 2014
Posts
324
Reaction score
19
Location
CT
Autozone tested my alt and battery and both checked out, the guy who tested had no idea what the issue could be.

My battery has 3 different wires coming off the positive terminal, connecter is definitely not stock. One of the three wires splits off and both go to the alt. Is this a stock configuration and is it something I should look into?

Not sure if this could be related, but when I shift between park and drive or reverse the car jumps slightly and rps jump as well. First thing that comes to mind would be a bad shift motor. Would this be a possible cause of the generator conditions circuit issue or vice versa?

Also I should note that the battery light does not come on until I shift out of park.

Thanks
 

stamp11127

Full Access Members
Joined
Mar 10, 2012
Posts
6,218
Reaction score
1,250
Location
Temple, Georgia
Alternator 101
In simple terms the voltage regulator(VR) in the alternator monitors battery voltage. When the battery drops below a specific voltage point the VR will "turn on" the alternator by applying power to the rotor windings. When there is a problem here the battery light will come on and or flicker.

Let me know if you want a more technical razzle dazzle speech on what is really happening in there.

So in other words you have a connector and or harness issue.
Since you stated that the connector isn't original, are you able to post a pic of the splices that connect it to the wire harness for the alternator?

Factory wiring diagram shows 4 wires plus ground.
 
Last edited:
OP
OP
2004XLT

2004XLT

Full Access Members
Joined
Sep 26, 2014
Posts
324
Reaction score
19
Location
CT
That'd be great stamp I'd like to learn all about it. I'll get a picture up tonight or tomorrow.
 
Top