Alternator problem?


#1

So earlier today when I tried to start my car it wouldn’t start! I tried cranking her over twice and I got nothing. The battery gage needle didn’t move when I tried starting her up the few times. What’s weird is that I took my other car (parents) out to run the errands I needed to run and when I got back I thought to myself “well maybe the battery is dead and needs to be jumped” that makes sense right? So as I pull up next to my car I decided to try starting her one last time and when I put the key in and cranked her over she started right up! Not a stutter or anything! So I’m left with the feeling that maybe it could be a failing alternator ? Or possibly a loose cable or something ?

Btw the car is a '98 Mercury Grand Marquis.


#2

I’m gonna guess a corroded battery cable connection or loose battery post (internally) or something of the sort, but it’ll need to be looked at to truly diagnose it. Other possibilities include a worn out key cylinder.


#3

@“the same mountainbike” hmm do you think that’s something I could have my local Autozone look at? Or is it better to just take it to a trusted mechanic ?


#4

To get a diagnosis *


#5

Take it to a trusted mechanic. AZ guys can mount a tire or change a battery, but you’re better off with someone with true diagnostic skills.


#6

Use the web to find a video on cleaning battery connections. It is not difficult at all. Cheaper than a $100.00 diagnostic fee you might not need.


#7

Alright will do… Would something like a corroded battery cable or loose post make it not work in colder weather? It was around 55 degrees this morning when I tried starting her., Just wondering because it was warmer around 1 today when she fired right up


#8

@“VOLVO V70” will definitely try that first!


#9

Idk if the posts look dirty or what not… But this is what they look like. Will try cleaning them tomorrow and post back results.


#10

Here we go.


#11

Those don’t look particularly corroded, but it is the part not visible – the surfaces between the connector and the post – you need to clean. You’ll need a special and inexpensive battery post tool gadget to do that.

A couple of other common reasons for this symptom are a faulty neutral safety switch (for an automatic), or faulty clutch safety switch (for a manual transmission). But before going down that path, make sure the battery connections are tight and clean. If the battery is over 4 years old, 3 if you live in a hot climate, that should be high on the list of suspicions too.


#12

@GeorgeSanJose that’s what I thought but I’ll clean 'em anyways and see what happens… Any idea what an estimate would be on what you mentioned in your comment above ? Cars an automatic btw.


#13

Replacing a neutral safety switch isn’t usually very expensive. But a good mechanic wouldn’t replace one just b/c this symptom is occurring. They’d find out why the symptom is occurring first, the replace or adjust the part that is not working. There’s a least a half dozen common reasons for the “fails to crank” symptom.


#14

Hmm alrighty then :slight_smile: I’ll try and start her tomorrow morning and see what happens. And also give it a clean down.


#15

Given the age I might suspect the neutral safety switch (allows it to start only in park and neutral) may be failing. This is referred to in more technical terms as a range selector switch.

If it acts up again try shifting into neutral to see if it starts. If so, it’s likely the switch is bad. The switch is not a major repair at all; if needed.


#16

You could search this forum for “cranking” problems and see what kinds of solutions others have found for this symptom.


#17

Saw a couple of different posts on cranking problems… I guess it could be possible a fuel pump relay is shorting and could need replacing ?


#18

Oh also the fuel pump itself was replaced just two years ago so I don’t think it would be that


#19

A fuel pump relay wouldn’t be the usual explanation for a fails to crank. That would likely be in the cranking system, so a battery, safety switch, ignition switch, starter motor, etc.


#20

Gotcha :slight_smile: just wasn’t sure.