O/T Daughters Mustang

[wildcard]

My daughter has a 2000 Mustang. With electrical problems.
This is what she says the problems are:
Her "charge gauge" is showing on the high side. ( I assume she's talking about the battery gauge )
The battery light flashes.
Her lights brightness goes in and out. (Probably getting dimmer and brighter.)
The higher the RPMs, the higher the voltage meter keeps going.
I told her to have it hooked to a machine that can troubleshoot it or give her a code. She said they told her there was nothing wrong with the car. She even had the alternator checked and they said it was good also.
She's afraid to drive it anymore for fear she may do more damage.
Can someone shed a light on what the problem could be ?
I'm probably going down there this weekend and would like to have some idea where to start looking and what tools I might need.

Thanks, Benny

[91Bear]

Voltage regulator?

[tsherry]

Internally regulated alternator, which is probably hosed. See if you can pull the alternator, have it bench tested, and if bad, replace.

(99% sure that's the problem, though).

Or, pick up a used alternator and install that.

[crazyhorse]

My 07 GT Mustang had some of the same problems.
I put a new battery in it and problem solved.

Do you have a new battery in another one that you can put in to see if that is the problem?

[wildcard]

I keep telling her to get another alternator and she says it's been checked. I was thinking the voltage reg. was built inside it.
She took a another battery from a different car and put on it but said it didn't make a difference. Maybe she has 2 bad batteries.
I appreciate the replies and advice.

Benny

[wildcard]

Ok, I went down there last Sat. and first checked the battery. It showed bad. Alternator tested good. It was putting out 14.6 volts.
Took the battery she took off and the one she had on it to get them both checked at a parts store. The one she had taken off first was 100%. Other one was bad. Went back and put the good one back on. Everything checked out good then.
BUT... she called that night and was having the same problems again after driving it around for about 30 minutes. So, daddy heads back down there Sun. morning. Everything is showing good again.
I decide to put the new alt. on. We drove it for a little while without any problem.
So, she heads out from Longview, Tx. to Bartlesville, Ok. (near the Kansas line I'm told) in it that night.
Now that's trusting daddys work
Apparently that solved the problem.
I was thinking it would be a nightmare to install but it went easier and faster than putting an alt. on my old I6.
Thanks again for the replies and advice.

[tsherry]

Ok, I went down there last Sat. and first checked the battery. It showed bad. Alternator tested good. It was putting out 14.6 volts.
Took the battery she took off and the one she had on it to get them both checked at a parts store. The one she had taken off first was 100%. Other one was bad. Went back and put the good one back on. Everything checked out good then.
BUT... she called that night and was having the same problems again after driving it around for about 30 minutes. So, daddy heads back down there Sun. morning. Everything is showing good again.
I decide to put the new alt. on. We drove it for a little while without any problem.
So, she heads out from Longview, Tx. to Bartlesville, Ok. (near the Kansas line I'm told) in it that night.
Now that's trusting daddys work
Apparently that solved the problem.
I was thinking it would be a nightmare to install but it went easier and faster than putting an alt. on my old I6.
Thanks again for the replies and advice.

Sweet. Love it when solutions are found. Tricksey stuff, 'lectricity!

[crazyhorse]

Mr Wildcard, congratulations on fixing the problem

[68RGR]

But, wait . . . You didn't tell us who said the original alternator was OK??

It might be good to know so others can avoid them!

[Craigerf100]

Yep that had voltage regulator all over it. Are those integrated into the alternator now a days, I assume?

[wildcard]

You got that right ,tsherry. Hard to figure out the problem when it shows there isn't a problem.

Thanks crazyhorse.

68RGR, I believe she went to O'Reillys. BUT..... I also tested it when I first went down and it showed good to me also. So I can't hold that against them.

Craigerf100, that's the way I understand it. It's cheaper to buy a new alt. than have the regulator inside them fixed or replaced. So I've been told.

My thinking is the voltage reg. was bad/weak and started breaking down when it got warm.

[tsherry]

Failures on those can be intermittent. We had one on a later F-150. Fortunately, the first part I threw at the problem was the alternator.