i had to buy two from walmart at 75 eachl. on thrusday
battery problem
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New User
Joined: Sep 2009
Posts: 18
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battery problem
my 2001 truck that i bought 2 months ago has lost its battery charge. it proggressively got worse and now its dead. Batteries are interstate megatrons and only 7 months old. What may be the problem?
Elder User
Joined: Mar 2003
Posts: 699
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From: northern Michigan
First thing is to put a voltmeter on the batteries while the truck is running to see if they are charging. Second would be a load test, Crank it while watching each battery with the voltmeter, should remain above 9vdc if they are good and fully charged. If they pass this you have two options left, Something in the truck is drawing juice while it is off or an internal fault within the batteries. Internal fault normally shows up on the load test as they won't hold well. First suspect in the truck for a slow draw is you lost a diode in the alternator. These are the most common.
More Turbo
Joined: Mar 2007
Posts: 636
Likes: 7
From: La Mesa, Ca.
A simple test for a bad Diode in the alternator is to test for any heat coming from the frame of the alternator after the engine has cooled down overnite. The alternator should be at the temp as the motor block.
Nick
Nick
Posting Guru
Joined: Mar 2007
Posts: 1,905
Likes: 2
From: East Peoria, IL
should the OPs batteries actually be at fault, he will probably get a pretty good warranty deal through Interstate. Good thing, seeing as how the megatron plus are $125 a pop
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Senior User
Joined: Sep 2009
Posts: 341
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First things first. Remove the batteries and charge them. After they have cooled down. Load test them. Replace them if they won't load test at 1000 cca. If the batteries are good reinstall them, clean the battery cable ends. Then start the engine and check the voltage to see that your alternator is working. Also check your dash light and gauge to make sure they are working. Might as well perform a voltage drop check on the batteries, cables and alternator as well. Doing this should get you going forward. Good luck.
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Mountain Pass
Joined: Jun 2008
Posts: 238
Likes: 2
From: Central Mississippi
I Know i have an alternator problem already, i only get bout 13.1 from either battery at idle, maybe its more while running because it only gives sluggish start after sitting for 3 or more days.
Maybe diodes, should i take alternator to alternator repair shop or just buy a new one, remanufactured?? Last one i bought for my other truck was about 165?
More Turbo
Joined: Mar 2007
Posts: 636
Likes: 7
From: La Mesa, Ca.
You can check the alt temp now to see if it is hotter than the engine block. If you are only getting 13.1 you do indeed have a problem. Mine gets to 14.2 immediately after start-up. We have a lot of good sponsers on the site to help you get a good replacement.
Nick
Nick
Cargo Master
Joined: Jun 2003
Posts: 3,292
Likes: 6
From: Ardenvoir, Washington
If your engine is cold, the glow plugs will be active for about 2 or 3 minutes. Measuring the voltage at an idle when the glow plugs are on will usually drop your voltage down to around 12 volts..but will jump back up to over 14 after a couple of minutes of running..
Senior User
Joined: Oct 2008
Posts: 466
Likes: 0
From: Ontario, CAN
Also with sluggish starts--Load test says 13.55 each battery at idle. Alt housing warm to touch after 1 minute at idle will try again in the morning. Batteries are originals from '01. I have an Equus volt meter and I am not quite sure how to test alt output. Any help?
Mountain Pass
Joined: Jun 2008
Posts: 238
Likes: 2
From: Central Mississippi
Check another thread I started on this,"13.1 on alternator".
There's several answers there also.
Cargo Master
Joined: Jun 2003
Posts: 3,292
Likes: 6
From: Ardenvoir, Washington
Another good test for batteries is to use a battery hydrometer.. (similar to checking your anti-freeze).. Napa sells one for around $20. You can check each cell fluid of the battery.. I always replace the battery if any one cell is weak.. Note: the battery must be fully charged to do this test..