Yet another alternator charging issue.

Greek

Greek

New Member
May 20, 2010
513
0
0
Ohio
'89 turbo is the car. The brake, battery, and bulb indicators on the dash are on. So I read up and it's the alternator not charging. I just did a fresh BHG fix, and the alternator wasn't charging. So I bought a brand new alternator and belt which fixed the problem. Then recently the lights came on. While running, the battery will read 12.3-12.8 volts with the lights on, constantly fluttering in between. I thought it was caused by the fuse, which was corroded green. Replaced the fuse Saturday and the lights stayed on for a few minutes, went away for the rest of the day. Yesterday at start up the lights were on, after a short period of time they shut off and didn't return.

This morning when I tried to start it up, it did some weird shit. It was as if the CPS wires were cracked again (which I just fixed). But after the third try of cranking it the car started. Lights stayed on halfway to school, then went off. Lights came back halfway back from school.

The lights would randomly come on while on bumpy road and on smooth road, so I don't know if that helps at all. The wires at the battery terminals are good, so are the ones on the alternator. Could it still be shorting out somewhere along the way? Or could the alternator still be defective?
 
TomFraser

TomFraser

New Member
Jun 6, 2008
418
0
0
Lakeville, Massachusetts, United States
What is the voltage reading when the lights are not on?

Where did you buy the alternator? I have gotten 3 DOAs in a row from autozone in the past, then 2 from pepboys, then finally a good one from toyota.

Since bumps seem to affect the problem have you checked simple things like cleaning the battery terminals, and ensuring they are tight, and making sure grounds are solid?
 
Greek

Greek

New Member
May 20, 2010
513
0
0
Ohio
TomFraser;1698376 said:
What is the voltage reading when the lights are not on?

Where did you buy the alternator? I have gotten 3 DOAs in a row from autozone in the past, then 2 from pepboys, then finally a good one from toyota.

Since bumps seem to affect the problem have you checked simple things like cleaning the battery terminals, and ensuring they are tight, and making sure grounds are solid?
Click to expand...
Voltage without the indicators is around 13 volts +. The alternator is from O'Reilly, and the battery is brand new as well so the terminals are good. Grounds are all good. Like I said, I'm not sure if bumps affected it. One time they did flicker on from hitting a bump, and other times I can get huge bumps and no effect. They also came on while driving on smooth road.
Kevin;1698388 said:
also check the wires connected to the alternator for corrosion and loose connections
Click to expand...

The plugs on the wiring seem to be in very good condition.
 
Nick M

Nick M

Black Rifles Matter
Sep 9, 2005
8,873
37
48
U.S.
www.ebay.com
Either the alternator is defective, or the belt is loose. That is assuming your wiring is kosher as you have declared. If the belt was a little loose, the lights would come on when acclerating.
 
Greek

Greek

New Member
May 20, 2010
513
0
0
Ohio
First thought was the belt being loose, but after making sure it was tight I still have the problems. Just started it up this morning, no problems. The lights came on then went away quickly. Faulty alternator? But why would it only do this at startup and then randomly while driving?
 
Greek

Greek

New Member
May 20, 2010
513
0
0
Ohio
I went and got the alternator tested and it is fine.

Jetjock, how would I go about doing it correctly? The three lights came on today, and while using a voltmeter they would keep coming on and off. When off, the battery would charge just fine. With them on, the voltage was around 12.3 and revving it raised it only .2 volts.
 
Nick M

Nick M

Black Rifles Matter
Sep 9, 2005
8,873
37
48
U.S.
www.ebay.com
On mine, the stud for the rectifier bridge was corroded. So it would intermintently not charge. I could wiggle the cable and voltage would waver from B+ to 14.1. I bought a new ND rectifier and brushes. And your light doesn't come on randomly. It comes on purposefully, you have to figure out why.
 
Greek

Greek

New Member
May 20, 2010
513
0
0
Ohio
Do you guys know which wire tells the alternator to charge? Would it be the yellow-green coming from ignition to the caution light? I was stranded at work today and had to get a jump.
 
hvyman

hvyman

Dang Dude! No Way Man.
Staff member
Apr 17, 2007
12,568
1
0
Fullerton,CA
Alternator is always charging. The battery is useless once the engine is started.

Are you getting 14v out put from the alt? Doesnt sound like it.

Again, Even new alts can be bad and it happens more often than you think.
 
Greek

Greek

New Member
May 20, 2010
513
0
0
Ohio
hvyman;1700161 said:
Alternator is always charging. The battery is useless once the engine is started.

Are you getting 14v out put from the alt? Doesnt sound like it.

Again, Even new alts can be bad and it happens more often than you think.
Click to expand...

When tested it maxed like 15 point something. It's putting out fine, just getting lost somewhere along the way.

I just jumped it and it read 12.3, revved it up and it charged up to 13.4. Let off the throttle and it went back down. Stowed away the jumper cables, got inside and noticed the lights turned off. This is a pretty weird problem. With my limited understanding of electronics, wouldn't a faulty fuse or wire either work or not work in this case?


edit-Triple post, lulz. Sorry, but this is so confusing.
 
You must log in or register to reply here.
Top Bottom