Car randomly shuts off

I'll be driving down the road, and just like that, my car will shut down on me. It can happen at any particular time (coasting, stopped, accelrating, breaking) including immediately after I turn it on. What will happen is that the entire electrical system will shut off for a second and the engine will completely shut off. I know the electrical system shuts down because the headlights will cut off, the backlights will cut off, the displays and the radio also cut off. If I'm driving, I can (luckily) just put it in neutral, turn the car right back on, tap the gas and put it back in drive and it'll run just fine.

Recently, I had it in the shop, and after a mass amount of diagnostics time, the only thing that they could conclude was I might need new spark plugs and wires. So I had them put in a whole new set for me (cost a pretty penny). The problem's worse now; it cuts off with more frequency. Just as a side note, before I had the spark plugs replaced, he noticed that the alternator was putting out a constant 100 amps and the battery leads were measuring in at 250+ degrees. As to my knowledge, an alternator should be capable of 100 amps, not constantly at. And I know 250 is waaaay too hot. I don't know about the alternator's output now, though.

If I think of anything else to add, I'll either reply or edit this message.

Oh, side note: after getting the spark plugs replaced, my transmission no longer skips. I thought that a transmission skip would be a new clutch or flywheel though? lol

I'd suspect the battery. Try getting it load tested at an auto parts store, it should be free.

Have BOTH the battery AND the alternator tested. Depending on your milage. you MAY need both. If you have near 100k miles.....sorry, but you are probly due.

I actually got a new battery about a month and a half ago, after which, it ran just fine for a few days (I'm suspecting while the battery had a full or near-full charge). After it started cutting off again, I had the alternator tested, and it's charging. Like I said above, though, it's charging at a constant 100 amps.

budpytco: Actually, I'm at about 99,6xx right now. haha But like I said, the battery's practically brand new, and the alternator, well... lol

Your battery won't last long with 100 amp charge going into it all the time.....

Haha, that's a good point. So I should just go ahead and have a new alternator and another new battery installed and hope for the best? Because I've had it three places for diagnostics, and all anyone can tell me is "wow, I've never heard of anything like this before."

I would start checking the grounds...off the engine and the alt, make sure nothing broke off and is now making intermittent connection

You don't mention the year or model of the Lincoln you have.

From my own personal experience with my 1998 Mark VIII, two things have caused this sudden shutting off of engine problem:

1. Worn front wheel bearing. The slight vibration confuses the traction control program, and it shuts the engine off. Replacing the wheel bearing fixed this. A warped rotor may also cause this.
2. Vacuum hose leak. One of the thin vacuum hoses on my manifold had a tear. After replacing this hose for a dollar, the sudden shutting off problem was solved.

Oh! Haha, I completely forgot about that. Don't I feel stupid. lol I've got a 1996 Lincoln Mark VIII.

BigBoyBoelts: I've checked all the grounds, and they're all fine.

Alexander: You know, it's interesting that you should mention that. I had my car in the shop about three months ago to get new brakes, and I also mentioned that my car had been squeaking a lot. The guy said that that was due to a worn down wheel bearing, but said that it shouldn't cause any problems, so I just set it aside for the time being.

Any idea how much this would cost to have replaced? What about a warped rotor? Because apparently that's another one of the problems with my car.

Edit: I'll go ahead and check/possibly replace the vacuum hose(s) on my manifold. What size are they?

mine does that too mainly on stopping, I probably have the same brake problem

When I had this happen, it was just a lose battery connection - but I bet you looked at those a hundred times already.

Well, I started thinking about it, would it really be the wheel bearings causing issues with the traction control? The only thing that's making me skeptical is the fact that sometimes (like an hour ago, for instance) the car will shut off about 20 seconds after I turn it on, while the air bags are still inflating.*

Also, like I mentioned previously, the only thing that the most recent mechanic could figure out is that it might've been the spark plugs. So he replaced all of them (and the wires). It cuts off even more often now. I (think that I) completely forgot to mention this in the original post, but it mainly happens at night, when there's an added load on the battery from the headlights, and even more often when it's raining and the wipers are on. Would this further suggest that it's the alternator? (considering that it's also constantly putting out 100 amps) When the mechanic had it in, I'm not sure if he did anything to the alternator, so for all I know, it could still be messed up.

Edit: *Possibly a problem with the airbags?

Everything I'm reading points to the alternator being bad, expecially considering its original. I bet if you drive around the block with the alternator disconnected it wouldn't be an issue. The alt should NEVER charge that much that often and if the regulator is stuck open, it could overload the cars electrical system, causing the ECU(computer) to freak out and shut down because of a surge.

The fact that the battery connections are 250* is NOT good.....

I don't understand how a shop can't find out whats going on after hours of diag time....its hard to find a good place now-a-days.

Get a volt meter and check it the alt yourself...if its charging more than 14.0 volts at idle/2000rpms you need a new one.

The wheel bearing will NOT cause your issue(why would the traction control shut off the headlights and interior lights/radio?).

A vacuum leak will NOT cause your issue(same as above, plus the car wouldn't start right back up)

You're issue is obviously electrical...get that alternator replaced or checked out by someone who knows wtf they are doing. If you were at my shop, I wouldn't have let you drive home with battery cables that heated up to 250* because if that battery explodes, you're in for some trouble. And, if you're still driving it around, you're playing with a loaded gun and also making matters worse.

BTW....anyone else want to comment on wtf the mechanic recommended spark plugs for an intermittant issue like this? Seriously.....did you take the car to Jiffy Lube or was it WalMart?

I recommend finding another shop, they are just taking your money, EXPECIALLY if they charged you for something that didn't fix the problem.

Thank you for the reply, J. =) I'm taking it back to the same mechanic today, but mainly because I already made an appointment to do so. He did, however, say that since the plugs didn't fix it, he'd do some free work for me to try to balance it out. I've got a list of most everything you guys have said (along with some stuff from another forum) that I'm just going to casually run through with him and see what he thinks.

Thanks for all your help, guys! And even though I'm not all that good with cars myself, because of all the posts, I'm strongly thinking the alternator too, just because it all makes so much damnable sense. lol

Patrick said:

it all makes so much damnable sense. lol

Click to expand...

Exactly! Haha No problem man, even if the alternator isn't causing the issue, it should be performing like it is.

On the other hand, the alternators on these cars have done some CRAZY stuff when they fail! One of mine failed and pegged my Volt guage at 16 volts...luckily I noticed it because my battery wouldn't have lasted long at all, and I might have had an exploding battery issue.

Well, I took it back to the mechanic today. He was on his lunch break, so he and I were just talking about what might be causing the problem, etc. Now, I should add that I don't look like a guy who knows a lot about cars. I start mentioning what you guys have been saying about a bad alternator, AC current going into the computer, stuff like that. He thought that I was just blowing smoke out of my ass. Finally, he shuffled outside and brought the car around and into the garage, and hooked it up to another machine. Sure enough, five minutes later he comes back in, attitude done a complete 180 and says:
"Yupp, your alternators putting some AC current into your system. That's probably why it happens more often at night, you've got more electronics going, more drain on the battery, so the alternator's working harder and, adversely, putting more AC into the system."

He went ahead and ordered the alternator for me and said it'll be in tomorrow. So depending on when tomorrow it gets in, I'll be reporting back either late afternoon tomorrow, or sometime on Wednesday.

Thanks again for all of your help, everyone!

I hope you're getting a ford reman, because if you aren't you are going to have some serious problems later down the road....

Serious as in how bad? I wish I'd known that 4 hours earlier.

Well many many members reported never-ending failures of alternators. Some changed them 4x or more before finally ending up with a Ford Rebuilt unit.

woo. haha, you had me worried there for a second. The alternator that I opted for comes with a three year warranty, so if anything happens within those three years, I can get my money back and put it towards a Ford rebuilt one. Thanks much for the heads up, though!