Truck cranks slow after sitting.
- Thread starter thx997303
- Start date
FarmerFrank
Full Access Member
Sounds like a draw somewhere. Alternators are good for that. You could either spend the tin and money tracking it down and replacing parts or put a master disconnect switch on it to shut off current flow from the batteries to the truck.
icanfixall
Official GMM hand model
Feel for heat in the alternator after it has sat a few days. Could also remove the heavy wire off the alternator too but be careful. that wire is constantly a hot wire. It goes from the batteries directly to the alternator so its looking for any ground to show you its hot. When a diode fails it stays closed when the ignition is switched off. When its closed the battery drains thru it to ground so the battery will die.
jada64
Boost Junky
How old are the batteries and the starter?
I had this same problem, looked at my batteries and they were 4 years old. But a nice set of interstate megatrons from my local interstate distributor for $124 out the door and now the only time I have trouble is when its below 0 for a few days. My block heater cord needs to be replaced and its too crappy out. I am trying to make it to spring.
I had this same problem, looked at my batteries and they were 4 years old. But a nice set of interstate megatrons from my local interstate distributor for $124 out the door and now the only time I have trouble is when its below 0 for a few days. My block heater cord needs to be replaced and its too crappy out. I am trying to make it to spring.
My truck does the same thing, but my batteries are 2 years old. I don't know where my draw is because I've been busy with other repairs, but it exists to a substantial degree. Maybe when the weather warms up and I am not on my back in wet I can spend the time.
On a side note, you won't lose your radio's presets if you run a hot wire directly from the memory wire to a positive battery post if you put a switch on your electrical system to deter losing current when sitting to something drawing. But if your batteries are bad, which we know they can be when brand new, that's not going to "fix" the problem.
On a side note, you won't lose your radio's presets if you run a hot wire directly from the memory wire to a positive battery post if you put a switch on your electrical system to deter losing current when sitting to something drawing. But if your batteries are bad, which we know they can be when brand new, that's not going to "fix" the problem.
Wyreth
Certifiable Noob
Almost certianly a drain.
Most parts places can simply test your alt, and tell you if the diodes are bad in it. I would be willing to bet money, it's your radio. Every single time I've encountered a drain, it's the radio has gone bad.
The simple quick fix. Go to harbor freight, and spend the $5 (it was $15 for me, as I have AGM batteries) for a float charger, then install it in your truck. Then simply plug your truck in if you're not going to drive it tomorrow.
My truck sits for weeks at a time, so this was worth every penny for me. Now the shedevil starts quick, the first time, every time, because of this.
Most parts places can simply test your alt, and tell you if the diodes are bad in it. I would be willing to bet money, it's your radio. Every single time I've encountered a drain, it's the radio has gone bad.
The simple quick fix. Go to harbor freight, and spend the $5 (it was $15 for me, as I have AGM batteries) for a float charger, then install it in your truck. Then simply plug your truck in if you're not going to drive it tomorrow.
My truck sits for weeks at a time, so this was worth every penny for me. Now the shedevil starts quick, the first time, every time, because of this.
Why not just make a quick check on the battery voltage after it sets like you say. If it's 12VDC or below, then you have a battery drain, if it's 12.5 VDC or above, then it's the starter probably.
http://www.batterystuff.com/kb/articles/battery-articles/battery-basics.html#3
http://www.batterystuff.com/kb/articles/battery-articles/battery-basics.html#3
bbjordan
Snow Monkey
Could be alternator or voltage regulator.
Do what OLDBULL8 says. Also, what is the charging voltage?
The diodes in the alternator could be failing. This will cause low charging voltage and battery drain. Double whammie.
The voltage regulator can cause poor charging too. You can check the connections and grounds to the VR.
I ran into a similar problem and upgraded to the 3G alternator. One of the best upgrades I ever did.
Do what OLDBULL8 says. Also, what is the charging voltage?
The diodes in the alternator could be failing. This will cause low charging voltage and battery drain. Double whammie.
The voltage regulator can cause poor charging too. You can check the connections and grounds to the VR.
I ran into a similar problem and upgraded to the 3G alternator. One of the best upgrades I ever did.
The alternator tested good. Batteries read 12.56 v and 12.6 v respectively on my meter, 12.9 on their tester. The batteries showed to have fairly equal CCA, about 1300 when they are rated at 1700 CCA. Less then I would like, but should crank fine.
Battery connections are clean and tight now. But the issue remains.
Battery connections are clean and tight now. But the issue remains.
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