91 Foxbody 5.0 - 36K miles - mostly stock, no electrical upgrades etc...
Jrichker has posted several times a step-by-step checklist:
http://www.stangnet.com/mustang-forums/threads/91-alternator-not-charging-tested-alt-good.881078/
Before I start this list, is there anything else that I should check?
It started this yesterday when my battery light came on. I used a DMM and measured 12v at the battery while running. The next time I started it, it wouldn't start (not surprisingly).
I started by taking off the alternator and taking it to to a local auto parts store (AAP). They ran a test twice, and both times it said my alternator was "good".
I went home, put the alternator back on and took my battery for an exchange (was last replaced 4 years ago). I put the new battery in, and same thing - won't hold a charge. The guy ran a test with the car running, surging etc (I've uploaded the readout).
Next thing I did was go to the local parts store and bought an alternator and voltage regulator harness. I was told these harnesses can get bad over time. I replaced the alternator even though mine checked out fine - you never know.. Still no luck. So I boxed that up and put my OEM alternator back on. I cut the OEM wiring harness and soldered on a new one. Still no luck.
So the problem is not:
Voltage regulator wiring harness
Alternator
Voltage regulator (a new one comes attached to the new alternator)
Battery
I need to look up an all inclusive list where all the grounds on the car is and check that they are clean and tight.
I don't have a light meter, so I will have to get one tomorrow to follow Jrichker's step-by-steps.
Any other ideas before I start? My battery light functions fine. A while ago I did change out my OEM bulbs in the cluster to LED - somehow the cluster seems to be tied to malfunctioning electrical, but I don't think this has anything to do with it.
Earlier I checked the Green/Red wire on the voltage regulator harness, and I think it was reading 12.5v with the key on.
Maybe the stator harness is bad? Can't seem to find a local parts store in Northern VA, so may have to order this. Trying to get this fixed by Tuesday, but not sure how this is all going to pan out.
Any help is appreciated--
--Shawn
Jrichker has posted several times a step-by-step checklist:
http://www.stangnet.com/mustang-forums/threads/91-alternator-not-charging-tested-alt-good.881078/
Before I start this list, is there anything else that I should check?
It started this yesterday when my battery light came on. I used a DMM and measured 12v at the battery while running. The next time I started it, it wouldn't start (not surprisingly).
I started by taking off the alternator and taking it to to a local auto parts store (AAP). They ran a test twice, and both times it said my alternator was "good".
I went home, put the alternator back on and took my battery for an exchange (was last replaced 4 years ago). I put the new battery in, and same thing - won't hold a charge. The guy ran a test with the car running, surging etc (I've uploaded the readout).
Next thing I did was go to the local parts store and bought an alternator and voltage regulator harness. I was told these harnesses can get bad over time. I replaced the alternator even though mine checked out fine - you never know.. Still no luck. So I boxed that up and put my OEM alternator back on. I cut the OEM wiring harness and soldered on a new one. Still no luck.
So the problem is not:
Voltage regulator wiring harness
Alternator
Voltage regulator (a new one comes attached to the new alternator)
Battery
I need to look up an all inclusive list where all the grounds on the car is and check that they are clean and tight.
I don't have a light meter, so I will have to get one tomorrow to follow Jrichker's step-by-steps.
Any other ideas before I start? My battery light functions fine. A while ago I did change out my OEM bulbs in the cluster to LED - somehow the cluster seems to be tied to malfunctioning electrical, but I don't think this has anything to do with it.
Earlier I checked the Green/Red wire on the voltage regulator harness, and I think it was reading 12.5v with the key on.
Maybe the stator harness is bad? Can't seem to find a local parts store in Northern VA, so may have to order this. Trying to get this fixed by Tuesday, but not sure how this is all going to pan out.
Any help is appreciated--
--Shawn