Emergency issue: Charging and warning lights

NoKittenMKIII

40mm BOOM
Mar 22, 2009
38
0
0
Sands of Iraq
Alright, I just had this issue pop up tonite, less than two hours ago. My voltmeter reads 9-11v, my oil pressure is at 20psi, and my brake and bulb warning lights won't go out (service brakes, ebrake, and taillights still function normally). Alternator belt is fine. No visible oil leaks, but it's hard to tell at night with a Surefire. Battery seems to be fine, no corrosion. I'm leaning toward the Alternator (either the internal voltage regulator or the rectifier). No squeal, so it's not the bearing. I saw no smoking wires, so I think the fusable link is fine. I'll check more in the morning, but I've only got two days to fix this.

Baselines: 14-15v, approx 40psi oil press. No issues with the ebrake, service brakes, or the taillights.

Am I looking in the right direction? Any other places to check?
 

toyotanos

What will we break today?
Staff member
Super Moderator
Nov 29, 2008
2,842
2
38
Coon Rapids, MN
Is the brake warning light still on? You might be low on fluid, or the switch in the reservoir may have failed. As for the tail warning light, check your brake lights too.
 

NoKittenMKIII

40mm BOOM
Mar 22, 2009
38
0
0
Sands of Iraq
toyotanos;1415790 said:
Is the brake warning light still on? You might be low on fluid, or the switch in the reservoir may have failed. As for the tail warning light, check your brake lights too.

These just came on with the charge light. I've checked the taillights, and they're fine (operational) and the brakes are fine. These just come on at startup and stay on.
 

NoKittenMKIII

40mm BOOM
Mar 22, 2009
38
0
0
Sands of Iraq
Update. Changed out the alternator ($105) and now I got belt squeal... Nothing major, just gotta mess with the belt tension. Should I loosen or tighten it?

Also, anyone know why the brake and light warning lights came on with a low charge condition?
 

Poodles

I play with fire
Jul 22, 2006
16,757
0
0
43
Fort Worth, TX
Brake,light, and check engine light will all come on if you get a low charge condition.

Belt squeal is usually a loose/old belt.
 

Angry7M

Formerly redmaro
Sep 6, 2007
733
0
0
36
AZ
Before you replace your alternator, I would check the fueses on the drivers side, under the dash.

It happend to me once ;)
 

shaeff

Kurt is FTMFW x2!!!!
Staff member
Super Moderator
Mar 30, 2005
10,591
11
38
Around
And to anyone searching that comes up with the same symptoms, before replacing the alternator, check the brushes. They ARE replaceable in the MKIII's alternator. And, they're super cheap, about $6 for the set!
 

89supra7mgte

New Member
Sep 20, 2009
797
0
0
colorado
I have a similar issue, Alt not charging (charge light not on but does work with key on) replaced with known good one (free) Test with voltmeter car running 14.2 volts, car revved up idled fine, then all of a sudden BAM alternator not charging except off idle? belt tight, all fuses appear to be good, only charges at 1k rpm or more at 14 volts. Let off throttle and it dies. I have been having an issue with an afm code as well (replaced) can they be connected? With the alt charging at idle i could snap throttle and it would not die now its back to doing that again. Help
 

mattman

New Member
Oct 8, 2007
96
0
0
Michigan
this post was just in time. my car too has this problem. But my goes form the normal 14v then will randomly drop to 12v then back up. i will see if i can get my hands on some new bushing so see if that will fix it. Thanks for the post. and thanks for all the info