dlister70

I can't seem to keep my truck battery charged. I bought a new battery because the old one was 5 years old, although it was still testing at the low end of acceptable.

The new battery didn't fix the problem.

When I turn the key, I sometimes get a click, and sometimes it will try to start. If it tries to start, it usually will start up because it doesn't need to turn over much in order to fire up. If I pull the battery off the truck and charge it manually, it will work fine until the battery runs down again.

I figured it might be the alternator, but when I get the truck started and pull the battery cables off, it stays running on the alternator. Once it's running, I can drive it however long I want to.

Is there another component I should be checking?

scope103

You haven't checked anything yet.

Use your multimeter (don't have one? No excuse for that: http://www.harborfreight.com/7-funct...ter-90899.html) to check the voltage at the battery when running. ~12.6v: just the battery. < 12.3v: discharged battery. ~14.1v: battery being charged. You should have about 14.1v at all times with the engine running.

Pulling the battery cables off is likely to damage the electric/electronic components on any vehicle built since about 1980. I guess (I hope) you were lucky.

If the alternator is producing anything more than about 10volts it might be able to keep the engine running, but it won't charge the battery.

MudHippy

Clean, or replace if necessary, the battery cable ends/connectors/post terminal clamps. Learn a valuable lesson about battery maintenance and solve the problem all in one quick swipe.

dlister70

After I posted this, I thought to myself: "Someone is going to tell me to hook up a volt meter and get a reading.. so I better go buy a volt meter."

I ended up buying the same cheap Harbor Freight one that you linked to before I even saw your post.

The battery read at 11.97v but in fairness, I had left the headlights on for about 30 minutes the last time I parked it. It took about 20 or so attempts, but I finally got it to turn over instead of click and it started up. I drove around for about a half hour to let the battery charge up a bit.

Now the battery is reading 12.94v, and it's 14.15v while the engine is running.

It sounds like the alternator is doing it's job.

The battery terminal connections are new within the last year or so, and I put those little felt circles on the terminals to help keep corrosion down. I had a corrosion problem with the previous connections, and decided to just replace them. The new ones don't look corroded at all.

Perhaps it's not a charging issue at all.. that's just what I thought it was from having intermittent problems getting the engine to turn over.

I'm not sure what to test next. It started right up after the 30 minute drive, so I guess I'll have to wait until the next time it just "clicks" and test the battery again to see if it's low when that happens.

wyoming9

iTrader: (1)

Have a battery charger ??

Charge the battery that way.

Back in the days of the Dinosaurs you could pull cables off a running vehicle now your asking for problems

Take pictures of your battery terminals

If your using those cheap emergency terminals that could be your problem

dlister70

It happened again today where I turned the key and got a "click" instead of trying to start. It happened a couple times, then it seemed hesitant to start, but I did get it started.

The battery read 12.6v when off, and 14.14v when started, so it didn't seem to be run down.

I apparently have something other than a battery issue, but there's a picture of the terminals just the same.

scope103

Carry your multimeter with you. Next time you get a "click," measure the voltage right at the battery terminals. If the voltage drops below 12.3 or so, your battery doesn't have enough charge to turn the starter. If it stays about 12.3v, your connection to the starter (cables, relay, solenoid) has enough resistance to keep that 12.3v from GETTING TO the starter.

While you're at it, you can move the multimeter probes off the battery terminals to the exposed copper of the wires. Your problem could be anywhere, but those terminals don't look too well-made to me.

Odin

You don't have to wait for it to happen again.
Since it's been a month I'm betting you already found it however here's some information to help you out next time. It's fairly easy to find if you're willing to learn how to do voltage drop testing, which is actually pretty easy.
Voltage drop testing can easily show you exactly where you are losing voltage.

You will be isolating and testing the POS and NEG side of the circuit one at a time to pinpoint the side with the problem. Then when you find the side that doesn't allow enough voltage to get to the area/part in question you start testing connection points. That will lead you to the exact connection point or cable with the problem.

This is a long video but please watch it with an open mind and then put it into practice. If you go about it one step at a time like what's described more than likely you will find your problem. It's often a touch of corrosion or just a loose connection that you haven't spotted yet. Many times people don't give the engine or body grounds enough credit and tend to overlook them. Being half of the circuit the grounds are just as important as the power wires. The grounds are the backbone of every circuit and I will always opt for a bigger cable than what came on the vehicle when stock. I'll also give the vehicle an extra grounding point or two. To overlook grounding points is a big mistake and has made many people spend a lot more money then they needed to on batteries, alternators and starters.

Just remember that the part you are testing needs to be under a load for you to find the problem during this test. Since the starter has a problem cranking it needs to be attempting to crank the engine or at least someone holding the key in the cranking position while you are testing. A helper to crank the engine and a couple of clamps for the ends of the meter leads/probes makes it a lot easier.


A couple of simpler examples






He's right, that type of connector should only be used as a Temporary Fix, not as a permanent solution. However many use those clamps as a standard fix only to have problems with corroded wires further on down the road.
Ultimately you do not want any bare wire exposed to the elements or corrosion WILL eventually start.

dlister70

Update to this old thread:

I ended up replacing the starter, and the problem went away. It was the original 1992 starter that I removed, so it had a nice, long life!

I'm not sure if one of the wires I removed and put back while replacing the starter actually fixed the problem, or if somehow it was the starter itself that was causing issues and it wasn't really a dead battery, just that the starter wouldn't turn over and made clicking sounds like it does when the battery is dead.

I suspect it was probably a solenoid issue, and replacing the starter fixed that. But who knows? I wish I could have been more scientific in solving the issue than just swapping parts and hoping for the best, but in the end, that's what worked!

thefishguy77

iTrader: (1)

Keep your starter and rebuild it or have it rebuilt. A lot of the ones fail quickly from the parts house. They bench test the cores before they rebuild them and if they pass it's not unheard of for them to just clean it and box it up.