Starter & Alternator?

What are the chances of a Starter & Alternator going out at the exact same time? Does the answer involve a double integral?

I have a 06’ Honda Element w/ 64K miles. Stopped at Stop N Shop for something real quick and it does’nt even try to start. Got power just starter will not even try. Send it over to trusty mech and he put in rebuilt starter. Then on first trip w/ the car to Home Depot lights on dash start coming on like a Xmas tree. Everything begins to fade and I just barely make it home. The alternator is out. Take it back to see if it was just the connections and he says “nope it is the alternator.” This mech never steered me wrong before. Is this just fresh out of warrenty blues or what? Was it most likely a short? Will something else go out immediately? Can they be linked?

Stuff does happen.

But there’s no real way to tell in your case without knowing what the mechanic did to determine a starter problem, whether the battery & charging system were checked etc. E.g. the first thing I would have done is put a meter on the battery and if I found it fully charged I would have ignored the battery & alternator & gone on to the starting circuit & starter. We don’t know what your shop did so there’s not much of a way to say.

I can at least say that a bad starter won’t take out an alternator - or vice versa. A bad battery can take out an alternator, and vice versa. But the starter isn’t involved in that interaction.

I’m wondering if the battery might be borderline failing and taking out both the starter and alternator.

I’m with Rod Knox on this one.
I frequently hear people brag about how many years they were able to use a battery, without considering the reality that a weak battery can wreak havoc on the much more expensive alternator and–in some instances–can also lead to starter failure.

Personally, after the first 3 years, I do at least an annual load test on my battery, and the first sign of weakness leads to battery replacement. And–even if a load test produces decent results, after 5 years, I just replace my battery anyway.

No-maintenance batteries can fail without warning, unlike the older designs that required regular replenishment of the distilled water. I can clearly recall an experience (after about 5 1/2 years) with my '86 Taurus, where the load test was “normal”, but 2 weeks later, the no-maintenance battery was totally dead, leaving me stranded on a cold winter night. Rather than be in another situation like that, for $65 or so, I just replace the battery after 5 years. I call that cheap insurance.

All things considered, your pre-emptive replacement of the battery is likely very cost effective, VDCdriver. That last 12 months of life in a battery might cost the nit picking driver a break down at an un-handy location along with a service call and a premium priced battery.

Rod Knox and VDCdriver,

I agree with both of you. I also wonder about the quality of the modern maintenance-free battery. I’ve had 2 batteries in two separate cars fail prematurely in the last couple of years. Both times, they simply refused to hold a charge out of the blue. One was just inside the 2-year free replacement warranty period, the other was not even 6 months old. Luckily, neither time stranded us somewhere on a dark, rainy night.

I’m one of those people who keep their batteries for many years. Average 7+. The LAST time I had to replace an alternator or starter on any vehicle was my 84 S-15. Since then…never had to replace one…even after over 300k miles. Battery life is really dependent on the climate you live in. The more heat the shorter life.