I recently posted about a weird problem with my 99 Mustang. It was shutting off while driving, and I could hear a 'boom' or 'thump' through the speakers when this happened. All the gauges would dive, as if all power was disconnected. But then it would either keep running, or I could start it up again. This was an intermittent problem, no pattern, so it was hard to reproduce for the mechanic.

The dealership put the car on the diagnostics twice, and said they couldn't find the problem. Then the third time they said "It's the alternator" and replaced it. That wasn't the problem. Last week I took it back with a dead battery (the third new battery in two years) and said I wasn't paying for the alternator being replaced because that wasn't the problem. They kept the car for a week, and the battery kept losing voltage every night. Now they're saying it's the 'motor harness' and it won't stay connected, and that caused the battery to go dead and the alternator to go bad.

Wouldn't the diagnostics show a bad alternator? Wouldn't a bad alternator just stop working? Did the wiring harness cause the alternator to 'go bad'?? And how much will it cost to replace the wiring harness??

I just don't trust these guys. I really dont think the alternator was bad, and they were just guessing. Any thoughts?? I appreciate any advice.

Both the alternator and the battery can be bench tested off the vehicle.  Also, the alternator can be tested on the vehicle, but doing so also tests the wiring in the charging system as well.  It sounds as though you obviously have a power drain somewhere, and a competent technician can easily track down one no matter how complicated it is.  Power drains typically come from bad parts or a wiring problems.  Sounds as though you either need an electrical device replaced or the faulty wire/plug/ or harness replaced.  Before you go changing all the harnesses in the car, find the problem first.

Just a question, have you recently or have ever had an aftermarket stereo system or alarm installed?  Those are the usual culprits.  Good luck, and if all else fails take it to a different dealership, your warrantly should cover (check to be sure) work at any Ford dealer.

Thank you so much for your advice! I'm pretty sure the stereo is factory. We are the second owners. I suspected the stereo as well since I could hear it through the speakers (like a power surge) but the first year I had the car it was fine.

This whole mess started a year ago. I'm concerned that the alternator didn't really need replacing. I spent $375 for that repair. How can I be sure it was actually bad?? They ran the diagnostics twice and it didn't show up. The third time I think they 'guessed'. Is there a way to get proof that the alternator was bad?

I don't really like these guys working on my car, but when I called customer service at Ford to complain they said I had to take the car back to the dealer who started the repairs because they know the car's history. So I'm stuck with them. And the warranty is expired...no extended warranty.

I'm making the mechanic put the cost of the alternator towards this wiring harness repair. They insist it was 'bad', but as far as I can tell it never stopped working. They said it was the 'bearings' and I don't know what that means, I understand the regulator and diodes and rotor, etc. Maybe they're talking about slip rings, not sure, but the car was starting just fine and running just fine when they said the alternator was bad. It was just shutting off, which was an electrical problem. I'm not giving in, those fools are not going to rip me off again.

Just cuz I'm a girl doesn't mean I don't know my alternator from a hole in the ground *grrr*

girls almost always get taken andvantage of, their usually easy pray... hey dont shoot me! Im just the messenger :)

Go get em girl, show em your not gullable (sh!t I cant spell that word)

*blushing* Nope, not gullible, not this time. I took automotive shop classes in high school with the guys, no home ecomonics for me!

Now they keep changing the price of the repair, Im sure to make up for the alternator job. First they said $295 for the wiring harness, and around $390 for the labor. From what I understand, Ford charges a set price for repairs, not by the hour. Is this right? Initially it was looking like the repair would cost $685, but now they're saying it costs closer to $900 or $1000 for this job. God damn parts monkeys...

Most dealership shops have set-rate for hourly jobs.  Jobs that fall under hourly charges are uncommen repairs, i.e. motor harness replacement.  Set rates for other jobs are for the more common and that are done all the time.

If you got a written quote, and it must be written, from the dealer they are only allowed to deviate 10% up or down from the quote.  If they say that they run into other problems while changing the harness.  Have them prove the problem.  Really show you.  Make sure you tell them that if the run into any issues that could raise the price they are to stop working until you see and tell them to continue.  This usually prevents tampering inorder to raise cost.  Inspect anything you look at and ask a lot of questions.  Things should be dirty not all nice and shiney if it has been a problem and one that has just been made .

Both the alternator and the battery can be bench tested off the vehicle.  Also, the alternator can be tested on the vehicle, but doing so also tests the wiring in the charging system as well.  It sounds as though you obviously have a power drain somewhere, and a competent technician can easily track down one no matter how complicated it is.  Power drains typically come from bad parts or a wiring problems.  Sounds as though you either need an electrical device replaced or the faulty wire/plug/ or harness replaced.  Before you go changing all the harnesses in the car, find the problem first.

Just a question, have you recently or have ever had an aftermarket stereo system or alarm installed?  Those are the usual culprits.  Good luck, and if all else fails take it to a different dealership, your warrantly should cover (check to be sure) work at any Ford dealer.