alternator question

[chad8]

My 95 corolla that i let my kids drive around has an intermittent no start condition. With a jump it starts instantly. This happens at random and not always when it sits a long time ,but usually when it sits at the kids school all day.
The battery was a one year old kirkland that I replaced today. The old battery had 12.4 volts and the new one that had been sitting for a month had 12.6. The alternator which is a junk delco puts out between 13.4 and 13.6 volts.
I tried to have the battery tested at autozone after starting the car once today to move it. They said it needed charging to test it and I did a voltage reading at 11.96 when I got home.
My question is this. Do I have a bad battery, bad alternator, bad ground, starter, or ?

 

[Billbert]

Sounds like you have an intermittent no charge or intermittent draw, tough to diagnose intermittents. I would start by disassembling and cleaning (wire brush) every connection You can find between Battery, Alternator and ground. Use a dialectric grease on all the connections, you can get the stuff at AZ.

 

[toyota62]

BATTERY OPEN CIRCUIT VOLTAGE SHOULD BE AROUND 12.6V AND UNDER LOAD 10+.CURRENT DRAW MUST BE BELOW 30MA

 

[onion]

I suspect a bad connection somewhere. It can be between the alternator and the battery, preventing an adequate charge (sometimes). Or it can be between the battery and starter (or ground), which will cause slow cranking and/or poor charging.

Check for obvious signs of bad connections like corrosion and loose hardware... but what can be less obvious is that wires and cables can corrode INSIDE the crimp where the terminal attaches. That can be hard to find. But melted/black/crispy insulation isn't uncommon on battery cables or alternator wires with this condition.

Also the surface of battery terminals and the like can become corroded- so that they wont make good electrical contact even if tight.

 

[chad8]

I am an electrician and have dialectric grease here as well as a spare alternator. I might add a ground wire next weekend and change the alternator if it happens this week. I was hoping the battery would solve it. My last kirkland on my other 93 corolla only lasted 2.5 years. They replaced that one for free too.

 

[Drew99GT]

Older Corollas are notorious for alternators failing, and once you get into the loop of free replacements remans like I have, it becomes a once every few years job. I can replace the one in my 94 Corolla in under 10 minutes.

 

[dwendt44]

It could be a bad starter.
I had just that situation a few years back.
Battery was new, would start right off; bext morning not enough juice to fire it off.
Went through two new batteries before traising it to the starter. High draw.
Of course, batteries sometimes are bad from the git go.
Another possible is it's not being run/driven enough to charge the battery back to full.
Seen that in a couple of real 'short trip' situations.

 

[Seguino]

Next time it doesn't start check the voltage before jumping it. That will rule out the battery and alternator if it is OK. Then try bending the battery cables and see if it starts. I had that problem and the cables looked fine but were no good inside where the copper wire meets the lead battery clamp. Hope that's it as battery cables are cheap.

 

[chad8]

Usually my kids have the car when it does not start ,but all are good suggestions. there is no corrosion on the cables or ends because i use dielectric grease and spray them with permitex corosion spray , but I have not checked the inner cables or starter connections.
I have rebuilt several corolla starter contacts and solenoids before and this problem does not seem starter related. They usually just click once when the contacts are burnt. I am leaning toward alternator or cables and if it were the battery I just replaced it today.
I just went out and checked the battery voltage to see if it is higher than the exact battery I replaced.It was not. Both are 12.4 after sitting although the other battery went to 11.5 after starting the car one time.. This problem can disappear for weeks and once the car is started it will be fine for a few days to a month. It has taught them how to use jumper cables . Not all bad.

 

[labman]

Onion may be right about the bad connection. I think sometimes they develop inside the battery. Could be tough to get it to fail when Costco checks it.

 

[chad8]

I started the car this morning and shut it right off. I did the same thing yesterday with the old battery. The new battery went from 12.40 to 12.31. The old battery went from 12.41 to 11.96. I hope the whole ordeal is from a bad battery. Time will tell. These Costco Kirkland batteries are made by Johnson Controls .I thought they were good ones. My first one in my other corolla lasted only 2.5 years. This one 12 months. As long as they keep replacing them , I will keep buying them as long as I do not get stranded. The 3 year full free replacement warranty plus price protection if it goes up works for me. I also get a new 3 year warranty every time I replace one because they make me take the old battery back and buy a new one. Who else does that!

 

[doitmyself]

I chased a charging problem on a farm tractor two years ago. I went through all the diagnostic tests and everything seemed fine, even the alternator put out ample current.

I don't remember the details, but somewhere in the electrical system was a bad relay ($25) that prevented proper battery charging from the alternator. A concurrent symptom was an unlit, "unrelated" dashboard light that also was fixed with the new relay. It was one of those "shouldn't be" fixes that drove my loony.

I have also had battery cables corrode internally (of the insulation)that looked just fine.

Any chance your kids are somehow running the battery down?

Good luck.....you never know when someone's anecdote might lead to a clue for another's solution.

 

[SteveSRT8]

The battery/starter/alternator triumvirate is always tricky.

You got great advice already, but judging from that last post your battery is bad for sure.

Good luck troubleshooting.

 

[brianl703]

The battery voltage drops after the car is turned off?

That could be because the car is continuing to pull current from the battery after the engine is shut off.

Do you have an ammeter? Inductive clamp-on kind with the capability to measure DC current is best.

 

[chad8]

I do have a clamp on ammeter (at work of course) but I used the volt meter just after I started and ran the car for 2 seconds with 2 identical batteries only one was a year old. It tells me that the voltage drop immediately after starting the engine and turning it off is way steeper on the older battery. The kids have not had a problem in 3 days and the car has sat outside and started in temps about 20 degrees twice a day . Once in the am and once after school.
I hope the older battery was just a [censored] one and started to fail after 6-8 months. That is the last thing you would expect to happen. That is why I test the easy things first.

 

[chad8]

well , its been a week of cold temperatures and the car starts fine. I bet it got cooked in the summer and was failing after 6 months. lucky this time out. I will keep everyone posted if it fails.

 

[L_Sludger]

Originally Posted By: Drew99GT
Older Corollas are notorious for alternators failing, and once you get into the loop of free replacements remans like I have, it becomes a once every few years job. I can replace the one in my 94 Corolla in under 10 minutes.
Yeah, it's an easy job but a bad design. My sister had a '94 Corolla. It went through something like four alternators and a half dozen batteries for the six years that she owned it. I credit ACDelco for the failures - her car had the awful Delco failternator.

 

[chad8]

I get the alternators at my u-pick junkyard for under $20. I have a denso in mine. Never failed yet in 4 years. The 2 delco's i have had both failed. I have another denso in the parts closet in my garage.
If you can change them in 10 minutes , you are a much better mechanic than i. I can never seem to get the bottom bolt to line up. It takes me a half hour or more . I hate it because I waste my hand trying to get that funky lower assembly in.

 

[L_Sludger]

That lower is no fun. But if you have a Denso alternator, you generally don't have to worry. A factory build or reman Denso is good to at least 150,000 miles. I've got the original Denso alts in four Toyotas and Lexus vehicles, each with at least 230,000 miles, and they still charge as they should. Imagine how many Delcos it would have taken to get them each to that mileage - maybe three dozen! I'd need to hook up with a distributor to get a volume discount on that,

 

[Drew99GT]

That must be why mine failed - when I got my first reman Autolite, it was the Delco style used for the Geo Prizm. I can't find the Denso style - all the remans at auto parts stores are Delco Remy.

I've found the biggest time saver to changing the alternator is to use an air wrench or an electric drill with a u-joint extension for the belt tensioner. Cranking the jack bolt by hand takes 5 minutes.