Moderator: volvite
So if the IPDM sees a lousy battery it will throttle down the alternator voltage? I was thinking belt/alternator largely because of the alternator voltage being 11.5V rather than the 14.3V or so it usually is.VStar650CL wrote: ↑Sun Sep 18, 2022 7:22 amOn vehicles which have the "smart" charging system controlled by the IPDM (as yours does), a very crappy battery can cause exactly the symptoms you describe without the alternator being bad.
You know, the battery is a four year old EverStart from Walmart (my go to). I discounted the battery as the culprit largely because last week, a 10 month old battery on my Minivan failed with a bad cell, which I only figured out after much hassle and an unnecessary starter swap.TooMuchControl wrote: ↑Sun Sep 18, 2022 9:03 pmjust to answer. The truck can drive without the belt on, I've done it around the block.
If battery is older that 5 years, I would suggest replacing it.
The car battery is the only thing people will let "die" rather than replace it at suggested intervals on cars.
Kirkland/Costco and Walmart is best (warranty/price)
I'm getting close to the magical 321868.8 km mark myself on my '05.
No, but with a crappy battery it doesn't need to throttle-down the alternator, just fail to properly throttle it up. Goofyware does goofy stuff when presented with goofy circumstances the programmer didn't account for.captngrif wrote: ↑Mon Sep 19, 2022 6:38 pmSo if the IPDM sees a lousy battery it will throttle down the alternator voltage? I was thinking belt/alternator largely because of the alternator voltage being 11.5V rather than the 14.3V or so it usually is.VStar650CL wrote: ↑Sun Sep 18, 2022 7:22 amOn vehicles which have the "smart" charging system controlled by the IPDM (as yours does), a very crappy battery can cause exactly the symptoms you describe without the alternator being bad.
Is 12v what you got while it was running? Did you try revving it to about 2/2.5k rpm and testing while reved? I would expect to see 14-14.5 volts. You may have a bad connection or alternator or battery.captngrif wrote: ↑Sun Oct 02, 2022 3:29 pmUpdate:
I charged the battery over a couple of days, measured about 12.33V once fully charged. Fired her up and the voltage across the battery dropped to about 11.99-12.00V.
Truck sat for a week, measured the battery this afternoon, 12.26V Went ahead with the belt, tensioner, and pully change. The pulley bearing was shot, and the belt was aged. Tensioner seemed ok.
Fired her up and same situation, voltage dropped to 12.00V.
I would think that charging the battery might trick the smart charging system into thinking the battery was ok. But who knows.
Guess I will try a new battery, 4 years old is ok I guess... If it was 5 years old I'd feel better about it. Kind of feel like I am throwing money at the problem.
The 12V or less, is what I am reading while its running, revving doesn't move the voltage at all.AS_The_Crow_Flys wrote: ↑Sun Oct 02, 2022 5:21 pmIs 12v what you got while it was running? Did you try revving it to about 2/2.5k rpm and testing while reved? I would expect to see 14-14.5 volts. You may have a bad connection or alternator or battery.captngrif wrote: ↑Sun Oct 02, 2022 3:29 pmUpdate:
I charged the battery over a couple of days, measured about 12.33V once fully charged. Fired her up and the voltage across the battery dropped to about 11.99-12.00V.
Truck sat for a week, measured the battery this afternoon, 12.26V Went ahead with the belt, tensioner, and pully change. The pulley bearing was shot, and the belt was aged. Tensioner seemed ok.
Fired her up and same situation, voltage dropped to 12.00V.
I would think that charging the battery might trick the smart charging system into thinking the battery was ok. But who knows.
Guess I will try a new battery, 4 years old is ok I guess... If it was 5 years old I'd feel better about it. Kind of feel like I am throwing money at the problem.
I would start by testing your battery with a battery tester to see if it’s any good. Voltage test alone is insufficient though it does look like it may be a bad battery, a voltage test alone is insufficient to make that determination at that voltage level.
Good info, I will take a look at the fuse tomorrow and report back.VStar650CL wrote: ↑Sun Oct 02, 2022 6:21 pmOne can kill the other, both ways. The battery is definitely trashed with a 12.3V float. Before you replace the alternator, check the field fuse. If it's blown, it's a telling clue that the alternator went bad and chronic undercharging probably depleted the battery. If it isn't, check your charge voltage after swapping alternators and make sure it isn't overcharging. That will also kill both. If the new one runs higher than about 14.5V then the culprit will be the battery current sensor, so either replace it or clip the smart wire.
The 13.3V is about right once the battery is topped up. Once it stops sucking charge and the current sensor reading drops, the smartwork will reduce the charge level. They shouldn't go under 13.0V or stay in the low 13's constantly even when loads are turned on, that's a sign of a bad current sensor.captngrif wrote: ↑Mon Oct 10, 2022 7:23 amGot the new alternator in, fired it up and voltage measured 14.40 at the battery everything looked good, let it idle for a while while I pumped up the tires and such.
Went for a drive, noticed the voltage reading on the dash wasn't as high as it was at first. Came home and voltage at battery measuring 13.33V at idle.