CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Alternator and/or battery issues... truck not starting; temporarily resolved, but

My truck (92 Ford Ranger, 140,000 miles) wouldn’t start. Had it towed to service center–apparently would have been able to drive it there had the tow truck op. jumped my battery (he didn’t because he was late arriving and I was ‘indisposed’ when he arrived and he had it part way on the truck when I got outside; I figured I’d still need to go to the service center–Ford dealer I’ve used happily for past 5 or more years–so I didn’t stop him.) Anyway, I could hear the starter attempt to engage then immediately begin the loud clicking which I assumed to be the solenoid, but no ignition or startup.

Ford dealer observed same symptoms on first attempt, so jumped it and it started right up. They ran their tests and determined the alternator was only putting out 13v and should be putting out around 14v. Also said after jumping it that the battery tested out just fine. They recommended a “new” (remanufactured) alternator AND a new battery. Reading some relevant posts in here shows that to be a reasonable suggestion. So why am I writing?

The battery is a DieHard, just over 4 years old, still covered under the “prorated 64 month warranty”, purchased at Sears. I didn’t want Ford to install a new battery for $109 plus labor if I might get my DieHard warranty’s value by going to Sears and save maybe $25-30. Hey, times are tough… But, there’s still an issue with the Alternator. And I left the truck at the Ford dealer overnight so they could do a full charge on the battery and see if the problem occurred again this morning. Which means it could be days (or longer?) before the battery is run down enough for Sears to see if there’s a bad cell or something else wrong with the battery. (I really don’t know, but the service mgr at Ford said this was a possibility… and I have been a satisfied service customer at that dealer/service center for years).

Part two: this “re-man” Alternator (it’s a Ford Ranger, so apparently “new” isn’t an option any more) will be the 3rd replacement in 7 years. The first two were at an independent shop affiliated with AC Delco, and the original equipment basically fell off the engine prompting the first replacement. That replacement did exactly the same thing just about a week after that shop’s 90-day parts/labor warranty expired… yes, fell off. That shop refused to replace the replacement, giving me only one option, $30 off the labor for a new full-price replacement. After that, I stopped going to their shop. That’ll learn 'em!

To shorten this increasingly boring story, I paid $90 to get my truck back from Ford today, but still have an alternator that they say will likely fail if I drive any long distances (I had a trip planned for this coming weekend), and still have a battery that may or may not have a bad cell, which may or may not be the reason the alternator is failing. The Ford folks, wanting to keep my business, will still perform the work for the original estimate less the $90 I paid today. But that is still a whole bunch more money than I feel I can afford to pay right now (I’m retired…)

So, is there a way for me to determine which came first (the chicken/egg issue): is the alternator failing because the battery is bad? is the battery bad because the alternator has failed for some other reason? If the battery is bad, could that be the only problem–even though the alternator test indicated inadequate voltage? In other words, do I really need to replace BOTH the battery and the alternator, and if so, is it foolish to replace one before the other, and/or at two different service shops? I mean, if Sears gives me the warranty value on a replacement battery, do I then pop right on over to the Ford dealer and have them install the alternator? And what if Sears says that the warranty is void because it’s the alternator that is bad?

I don’t have any idea which way to go on this, and I don’t know how to know what I should do?

This alternator did not kill the battery. Sears can test just the battery to see if it qualifies for replacement. Do not fall for the bs “we have to check the charging system”. That is not actually in the warranty. Your alternator is working and the regulator is not dead “it works”. The only thing that would kill the battery is a dead short on the charging system side. The batteries do have a habit of having weak plates to save on lead. These deform and kill a battery within the normal service life.

Start simple, check all the connections, Yes in the olden days this was SOP, but now it seems hook it up to the computer and scratch your head as to what it really means.

I suggest you take the car to Sears and have them check the charging system and battery. If the battery does have an issue they can determine that very quickly and easily. Idealy, it is a good thing to replace a fairly old battery when the alternator is replaced since they work together. If the battery checks ok though you still may get a couple or years out of it and not hurt the alternator.

The problem you had was due to a drained battery but how that happened doesn’t seem to be known at this point, unless you left something turned on in the car. The trouble could be due to a parasitic drain and something in the car is turning on when it shouldn’t be. There are ways to find the source of that kind of problem. The trouble also could have been due to dirty battery connections. Tell the shop exactly what happened and any details you can think of which can help them determine the real cause of the problem if the charging system checks out ok. Since the charging voltage was a little low there may be some bad diodes inside the alternator. A load test on the charging system will tell the story.

Thanks for the comments and advice. I took it to Sears and they ran their tests and said the battery was “fine” and the alternator wasn’t a problem. I explained the problem in as much detail as above, yet the response was that alternators produce variable output because they are not always running full-bore (my words, not theirs). They said they could beat the price Ford quoted for an Alternator and battery, but then after the test said I didn’t need either (also said it would be a new alternator, not a “re-man”… using Mazda parts since Mazda still makes essentially the same truck).

I have to decide where to place trust… Sears could have sold me an expensive repair and I wouldn’t have known better because another shop (Ford) told me the same thing… but Sears didn’t, and I assume they value their reputation so wouldn’t tell me everything was okay if it wasn’t. They also said I should be able to get another 2-3 years out of that battery (the “normal” Die Hard expectation of 6-7 years total). The “only” thing Sears noticed was a “crack” in the serpentine belt. (I gave the belt a cursory look in my garage before I went to Sears, but didn’t rotate it or really ‘dig into’ it… so I can’t argue with that diagnosis.)

Has anyone bothered to check the battery cables?
If the truck was jump started correctly the negative terminal from the charge source would have been hooked directly to a ground/ likely directly to a bracket on the engine.

In effect bypassing the possible failing main ground cable.

Also have a technician check the voltages and amp draw through out the start circuit this includes the signal from the ignition switch to the starter relay, both of these components are common failures on Fords.

This entire diagnosis should take about 1/2 @ most.

Good Luck