Truck Randomly Won't Start

[balladbeach24]

It seems like my truck doesn't like weekends. I have to jump start it every Monday, it will run the rest of the week, but if I use my girlfriends' car on weekends, I'm back to needing to jump it on Monday. This just started within the last month or so. It's an 06 with 187k miles on it. I'm kind of at a loss here anymore. Anyone have any ideas? Thanks in advance!

 

[therealmattryun]

It seems like my truck doesn't like to weekends. I have to jump start it every Monday, it will run the rest of the week, but if I use my girlfriends' car on weekends, I'm back to needing to jump it on Monday. This just started within the last month or so. It's an 06 with 187k miles on it. I'm kind of at a loss here anymore. Anyone have any ideas? Thanks in advance!

When's the last time you replaced your battery? It could just be time for a new one. This was happening to me intermittently for a little bit a month or two ago and a new battery solved the issue. Not to say it couldn't be a draw on the battery from something else, a battery would just a good place to start I think.

 

[balladbeach24]

When's the last time you replaced your battery? It could just be time for a new one. This was happening to me intermittently for a little bit a month or two ago and a new battery solved the issue. Not to say it couldn't be a draw on the battery from something else, a battery would just a good place to start I think.

I replaced the battery about a month ago, when I first noticed this happening. The battery tested as bad, so it got replaced then. I'm wondering if I got a defective one? I haven't installed anything new that could/would cause a vampire draw, but don't know of a way to verify if one is happening or not.

 

[Bumbo]

I replaced the battery about a month ago, when I first noticed this happening. The battery tested as bad, so it got replaced then. I'm wondering if I got a defective one? I haven't installed anything new that could/would cause a vampire draw, but don't know of a way to verify if one is happening or not.

My first guess would have been the battery as well.

Very easy to test...

You can use a DC clamp meter around the battery cable to see what type of current is moving in a resting state. This method is easiest but also not as accurate.

The other option is to remove one of the battery terminals, and connect a digital multimeter inline. More accurate, but requires more work.

Also, don't key on or try to start the car with the meter in line... chances are you will end up blowing a fuse. Most meters are rated at 10A max.

Eric The Car Guy
https://www.youtube.com/watch?v=KF1gijj03_0

 

[therealmattryun]

I replaced the battery about a month ago, when I first noticed this happening. The battery tested as bad, so it got replaced then. I'm wondering if I got a defective one? I haven't installed anything new that could/would cause a vampire draw, but don't know of a way to verify if one is happening or not.

If you started noticing the issue after you replaced the battery, I'd be leaning more towards that being the cause of your issue than a coincidence. I don't have a ton of knowledge on how to test your battery though, I've never had to deal with that much outside of just troubleshooting whether I had an issue with the alternator or the battery. I'm not sure where you got your new battery from, but I know the one I got from autozone has a pretty good warranty, maybe they could check to see if your battery is faulty?

 

[Bumbo]

If you started noticing the issue after you replaced the battery, I'd be leaning more towards that being the cause of your issue than a coincidence. I don't have a ton of knowledge on how to test your battery though, I've never had to deal with that much outside of just troubleshooting whether I had an issue with the alternator or the battery. I'm not sure where you got your new battery from, but I know the one I got from autozone has a pretty good warranty, maybe they could check to see if your battery is faulty?

While its possible for the new battery to be bad, its highly unlikely.

If the battery tests OK, and it's not parasitic draw, I would

a) measure the voltage with the car running to check the charging system (I could consider anything 13.5-14.9v good)
b) use a multimeter to check the resistance of the battery connections, and ground.
c) inspect for any corrosion or fouling that could be causing intermittent/bad connection/areas of high resistance.

Clean or replace damaged as needed.

 

[DMX512]

Could be the rectifier circuit(diodes) in the alternator. If alternators still have rectifier circuits in them...been a long time since I have torn one apart.

 

[BlackWorksInc]

[MENTION=144483]Bumbo[/MENTION]

Follow what he says, parasitic draw is most likely. Any recent mods you've thrown on in the last month or two? Even something as stupidly simple as the back cargo light being left on?

Could be the rectifier circuit(diodes) in the alternator. If alternators still have rectifier circuits in them...been a long time since I have torn one apart.

Unlikely if the vehicle is sitting and draining the battery without being driven. But anything is possible.

 

[Atlanta_man]

What's the acceptable/normal parasitic draw ? One that will allow a restart after say 10 days of sitting unstarted, given a good battery.

I've got some parasitic load items I want to add but trying to find how much load is too much.

Safest bet is probably to use a separate (small gel-cell) battery that recharges from the main.