2005 Mustang V6 Vehicle Electrical System Problems

MUSTANG7 · 10-21-2007

Hi Mustang (Fan)Community, I'm a new Member and this is a try to solve my following Problem: since last February I own a 2005 V6 Mustang, from the first Day I determined a more or less strong Fluctuation in Brightness of the entire Vehicle Electrical System. Everything in the E-System, Head-, Rear-, Interior Lights, Instrument Cluster,etc is affected. All Components getting darker and brighter all the Time. This Phenomenon appears all the Time, no matter if I'm on the Higway or in Idle Condition. In Addition, if this Phenomenon occurs, I have a light bucking when I'm going to Stop or parking the Car at very slow Speed. I bought a Diagnostic Tool, but it says: Test passed. With no Fault Codes. I checked the Battery: it shows Green. I've learned that the Alternator is under Control of the PCM, may be there is the Reason. So, in the Moment I'm at a loss with this LIGHTSHOW.
If there is somebody who knows, please let me know.
By the Way: I have the same Problem with refueling the Car like one of the Members mentioned in the Forum. I'll try the advice to wait a Moment until starting to refuel. That Thing with remaining Air Pressure inside makes Sence.
So far.
Thanks a lot in advance,
Lightshow

**stlwagon** · 10-21-2007

Welcome to AFM... Have you had any problems with water leaking into the car?

MUSTANG7 · 10-21-2007

Hi,as far as I can see, my car has no Problems with leaking Water from outside. My Interior is absolutely dry. Normally the first Sign for Water in the Car is having lots of Fog/Humidity on Windows and Windshield from inside. But I have to mention that I got a new Windshield, because the old one was cracked in the mid lower Part. I think it happened during Transportation from LA to my Homecountry.

Martinez1708 · 10-22-2007

well from my experience with my Hyundai (yeah i know). But, i was getting the same thing. It was the Alternator. I think Autozone will test the alternator for free, you might want to find out and get it checked out. It sounds like that might be the problem to me

MUSTANG7 · 10-22-2007

Hi Martinez1708, thanks for the Input. I have suspected especially the Voltage Regulator inside (thats bad) of the Alternator. I'll see my Ford Dealer next Fri to check the Charging System. But today, I can't believe it, no Lightshow! Absolut normal Behavior. What the Hell is goin'on? May be the System likes Temperatures around the Freezing Point?! I don't know. But the good Thing: with or without the Phenomenon, the Car is runnin'. It's just annoying and I would like to have it fixed. I'll keep an Eye at the Alternator, I think you're right.
Again, thanks a lot.

**stlwagon** · 10-22-2007

The alternators on these cars aren't the best.

MUSTANG7 · 10-22-2007

Are you having any Recommendations for an Alternator Brand / Manufacturer?

MUSTANG7 · 11-22-2007

update for this thread: it was the alternator (voltage regulator)! I went deep into the wiring manuals to see how's the charging system working and what kinda job does the pcm to the electrical system. just when I found out, the alternator went to the fritz completely(3 weeks ago). so this alternator failure shows up 8 months ago with the described symptoms. so next time these things going to show up, I can start kissing the alternator good bye.
see "electrical issues" in the GT forum also.
Thanks for helping!

jh1s · 11-24-2007

I have a 2005 v6. Have replaced 3 alternators, a battery, and now the entire dash wiring harness. Whew, thank god for the extended warrantee I purchased

**stlwagon** · 11-24-2007

Quote:

Originally Posted by jh1s

I have a 2005 v6. Have replaced 3 alternators, a battery, and now the entire dash wiring harness. Whew, thank god for the extended warrantee I purchased

You're not having much luck with alternators are you?

Tinman62 · 11-24-2007

Try disconnecting the battery for 30-60 minutes. Computers often retain "computer faults" that the will never show up on the fault communicator. Its the nature of a microprocessors. Draining the power for longer then 30 minutes allows the capacitors that hold the temporary power to discharge and the faults drop to their nature "factory new" state.

Its an issue with most car computers that applied the OBD2 design.