Diagnose La Llorona's car troubles!

Come on, you know you want to. :wink:

For circumstances that are not relevant to the matter at hand, a friend occasionally allows me to drive her car. Today was one of those days. I hopped in the car (a Buick–not sure of the exact date it was made, but probably '95-'98). I drove about four miles, shut off the car, left for about ten minutes, started the car again, and drove about half a mile down the road–no sign of car trouble.

I stayed there for about an hour, during which time the car was sitting out in a very hot sun. The temperature was somewhere between eighty and ninety degrees (Fahrenheit! :slight_smile: ). When I got back in the car to drive home, I noticed that the turn-signal indicator on the dashboard wouldn’t blink or make clicky noises (that’s the technical term for it, don’t you know), and that the Anti-Lock Brake System light on the dashboard was on. I really ought to have let the car be, but I did have one more errand to run, so I went out again immediately after I’d driven back home (three miles).

I drove to another place that I would estimate to be about three miles away. During the drive, I noticed that the turn-signal lights still wouldn’t work (I’m somewhat doubtful as to whether the outside lights were working), that the ABS light was still on, and that the Brake light (which I have always understood to mean that the emergency brake is engaged) was on. I checked the emergency brake, but I hadn’t accidentally engaged it.

I hurried up to run my errand, and came back within about five or ten minutes. When I went to restart the car, the engine sputtered several times before I could get it to start. The situation was still the same with the turn-signal lights and the brake lights.

I drove home with fear and trepidation and immediately telephoned a fellow who is somewhat vaguely knowledgeable about cars. This fellow came over about twenty minutes to half an hour later; he popped the hood and drove it around the block, and said that no Scary Indicator Lights had gone on for him.

“Maybe it’s just all this heat?” I asked.

“Maybe,” he said doubtfully. “When’s the last time this car had its oil changed?”

Of course, I hadn’t any idea, as the car doesn’t actually belong to me, and I’m afraid to say that my friend was equally ignorant when I asked her.

This fellow said that the car was most likely safe to drive, and I telephoned my friend to let her know about all this business, whereupon she said that I was still free to drive the car for the rest of the day.

Several hours later (it was evening, and considerably cooler), I drove to a friend’s house (I would estimate it’s about five to six miles away) and drove her back to my place for a visit. No noticeable car troubles. She stayed for about two hours; I drove her back home, not noticing any problems with the car. Then I decided to go for some late-night fast food, and we all know how late-night fast-food drive-throughs are.

Everybody shout it out: CROWDED!

I was probably there for twenty minutes or half an hour with the car on (I was downright terrified to turn it off), and during that time, the ABS light came on again, and the turn signals started not clicking/blinking again (although they did work later on in the drive).

All in all, I would estimate that I had the car on for a good hour during that last trip, and when I came back, the ABS light was on, but not the brake light, and the dashboard indicators for the turn signal were failing to blink/click.

When I told this story to my friend, she cast upon me the kind of cold and speculative look that just screams, “La Llorona, dear, you were driving it at the time, so don’t you think it would be only fair…?” I’m positive I’ll end up paying at least half of whatever the repairs cost.

Yes, I realize that I do not know you and that you are not my mechanic and that this is not a legally-binding car trouble diagnosis, etc. But what, based on that information, do you consider would be likely to be wrong with this car? What repairs would need to be made for a car with that type of problem, and roughly how expensive are they?

(P.S. Oh, and I should also mention that I have lately noticed a very faint, high-pitched whirring noise upon pressing the accelerator.)

(P.P.S. And if anyone shouts “It’s obviously the ABS, dumbass!”… :stuck_out_tongue: )


Hey now, I toldja it was a Buick, not a Gremlin! :wink:

I’m just a backyard hack mechanic but I’ll take a shot.

I’m leaning towards one of two possible problems.

Problem 1: Loose ground wire or corroded or otherwise bad ground path

If you’ve got a loose or corroded or bad ground somewhere, everything on that circuit is going to act screwy. It may get better or worse as the car moves around, and may completely go away at times. Most cars ground through the frame, so it’s quite common for rust on the frame to interfere with the ground system.

Problem 2: The alternator is about to die a horrible death

If your car isn’t charging right, it’s going to slowly drain the battery. As the battery voltage gets low, the electrical system will start doing really weird things like having lights come on for no reason or having relays (like the turn signal relay) not have enough power to turn on. If the car sits for a bit the battery might recover a little (it’s one of the weird things batteries do). An easy way to test for this one is to turn the lights on. If the lights get dimmer and dimmer then the car isn’t charging properly. Warning - do this somewhere where you can get a jump start, because if the lights get dim enough then the battery will be drained to the point where the car won’t start either.

I’m with brother engineer_comp_geek on defective ground being the problem. When I did auto body work and would occasionally move/drive partially disassembled vehicles where body/chassis grounds were missing, dash displays were totally whacko.

i was thinking “alternator” while reading your post… i would be hesitent to pay 1/2 the price to fix a bad alternator as it may just be (bad) luck of the draw being the one driving it when it went…

An easy way to test an alternator:

Start the car and then remove one of the cables from the battery. If the car continues to run, then the alternator should be ok. If the car stops, then the alternator is not working properly.

We’ve been down this road several times over the last year, and permanent damage will be done to the electrical system by disconnecting the battery with the engine running. Please don’t tell people to do this!

Disconnecting the battery with the engine running is an absolutely WRONG thing to do. Do not do it, do not suggest it, do not defend it.

I agree that the prime suspect is a poor connection. With its being intermittent, it may be the devil to find and fix.

This: “La Llorona, dear, you were driving it at the time, so don’t you think it would be only fair…?”

…is not justification for this: I’m positive I’ll end up paying at least half of whatever the repairs cost. The fact that you happened to be driving it when the symptoms appeared does not mean that you in any way caused or contributed to the problem – other than in the most general sense of providing a tiny percentage of the overall wear and tear on the vehicle. If you want to pay something on the basis of acknowledging the favor of being lent the car, fine. If you are asked to pay on the basis of being responsible since you chanced to be driving it at the time, that’s horsecrap. You didn’t break it.

I know! Oh, do I ever know. But…eh. Friends. “Friends.” Can’t live with 'em, can’t live without 'em, no? :frowning:

At any rate, tomorrow’s Monday, so I’ll know the bad news soon enough…thanks for all the help, folks.

Add me to the Don’t even think about this group. Disconnecting the alternator can cause a huge voltage spike which might kill a control unit or three. Control unit can very very spendy.
[Dirty Harry]
So do you feel lucky punk, well do ya?
[/Dirty Harry]
I’m in with the bad connection/ bad ground/alternator crowd.
I also agree that it is not your fault, just your turn in the barrell bunch.

…Really? wow. Ok, I guess I won’t try that ever again! Sorry, guys!

I’ll agree that it’s either a bad ground or a charging problem, possibly a bad control unit. My money’s on it being a bad ground somewhere, especially since it sounds like the car may be intermittently used. I don’t think that it’s something that anyone could troubleshoot without looking at the car.

You friend may get off with only paying an hour or two for diagnosis, or the job may require several hundred dollars in parts and labor. I hope that she has a mechanic that she trusts or has either deep pockets or friends with a soft touch.

Ouch! You wanna come over here and say that where I can hear you? :wink:

It turned out, says the auto mechanic, to be the battery–one hundred and eighty-one dollars exactly for parts and labor. We shall see who ends up paying for it…(cue ominous music)