Drunner97
New member
It's at 12.5, I put the tender on it. Gonna give this a try shortly.
Alternator not charging at idle
- Thread starter Drunner97
- Start date
It's at 12.5, I put the tender on it. Gonna give this a try shortly.
Drunner97
New member
Cleaned MAF, throttle body, coil pack connectors while it was opened up, charged the battery up to 12.9, started her up. Held 690-710 rpms for about 10 mins, with 13.7v charging. RPMs dropped down to 490-500 after 10-12 mins, showing 13.48v but holding. Going to let it idle a little longer and see if it drops down to the 400-450 it was doing earlier.
CrazyNorwegian
New member
Sounds promising. I'm not sure what the correct idle speed on the 4th gen v6 is, but that still sounds low to me. I don't think my 5th gen ever drops below 800.
Drunner97
New member
We must have posted at the same time. Jumped back up to 700 and held steady.
Drunner97
New member
So far so good. Running idle is just under 600. Almost didn't want to start when I left for the store, but I'm attributing that to sitting in the driveway idling. Started right up leaving the store. Shall see what it does in the morning, for now I'm cracking a beer and calling it a night. [MENTION=66389]BlackWorksInc[/MENTION] thank you much, for now you've saved me a major headache and throwing money at parts.
SoSoRunner
New member
Glad you got it figured out Danny! Now I should prolly do all these checks also, first things first when I get home today is to check to see if I'm getting over 12v at idle.
Drunner97
New member
Not quite out of the woods yet. Click, delay, start this morning. Took the kid to school, went to the gas station, got gas, started right up with no delay. Didn't really get a great charge yesterday running around so the battery was probably just low from all the testing. I'll see what happens when I go to lunch after my 45 min commute this morning.
SoSoRunner
New member
You still may have a problem with the starter...did you replace that yet? I'm going to change my plunger/ contacts inside my starter this weekend, this is the kit I got http://www.amazon.com/gp/product/B0031HMS7C got it from this thread http://www.toyota-4runner.org/4th-gen-t4rs/209957-replace-starter-contacts-plunger.html
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Drunner97
New member
Not yet, spent the weekend troubleshooting the alternator. It's almost acting like it's a bad battery, but unless the Tacoma battery was bad too it's not that. I may just take both batteries to autozone and get them load tested to rule that out at least.
SoSoRunner
New member
Yeah it may be the batteries, but also check out my post above I just inserted some links. The symptoms mentioned in the thread are exactly what we're experiencing. It's only a $14 part and a few hours labor so I'm going to give that a try before buying a new battery or starter.
Drunner97
New member
Cool, I'll give it a read when I get a spare minute today.
blackoutt
New member
Did you ever resolve this? I see you did a bigger alternator and big 3 after this but didn't know if you did any starter work or starting issue ever resolved? I crossed some deep water with my v8 and now have low charging voltage at idle 12.something and an intermittent no crank no start but always starts within another try.
Drunner97
New member
For the most part. First get your battery load tested, make sure it's good. Then get it charged fully, at least 12.6-12.7, clean the maf and throttle body while charging the battery. Once the battery is charged, hook it up and let it idle with all accessories/ac etc turned off. It'll take about 10 mins, but the idle should reset itself if everything else is good. Before doing all that you can try testing your alt but having someone watch the multimeter on the battery while you rev the engine. Should see voltage go up as the rpms rise.
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blackoutt
New member
Thanks for the quick reply. Batteries are newer AGM's and have been topped off, no indication that they are bad. Alternator does charge while cruising but just seems low at idle this is with lights and accessories running, comes up to 13.0 range with everything off so maybe it's not bad, might need an idle relearn. Maybe I'll try to do this in techstream.
The charging thing only partially concerns me, it's the no crank no start that I fear will leave me stranded. Did that just resolve itself?
Drunner97
New member
My no crank issue was likely related to my battery issues, which was related to charging. With the stock wiring and stock alternator I was finding that I could only charge at about 13.6v. With 4g wiring for the dual battery setup I was only sending 13.2v to the house battery. After I changed everything to 1/0g, big 3, and 240a alt (which may not have been necessary, but I never threw my stock alt in to check) I've been consistently getting 13.6-14.2 charging on both batteries depending on how low my house battery is. When they're both fully charged I'll see 14ish across them now.
I'm still having the low idle issue on occasion, especially in gear. The alternator won't start charging until 650rpms, anything lower than that and you don't charge. I'm chalking my issue up to the way I did my dual battery setup and that the ecu keeps trying to reset my idle based on load. I can reset my idle, it'll run correct, until I add the fridge. Once the fridge is running something changes and it thinks I'm under load all the time. I dunno, it's weird and I haven't cared enough to look into it. If techstream can set a hard idle at 650-675 without adjusting that may be the way to go.
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blackoutt
New member
Just weird that both our starting issues started after water crossing. I've had the fridge and dual battery setup in for almost a year now with no issues so I don't think it's related to those items. I did add solar last fall so maybe that's effing it up.
Sounds like I'm going to go through and clean all my connections and might solve my starting issue based on what you've done essentially touching everything that could have been corroded. I have 1/0 between the batteries but no big 3. My starter will be about impossible to get to down in the V unless I remove my intake manifold though so that one will be done last if I can't fix it with the easy ones.
Drunner97
New member
I've got solar too, but the solar charger doesn't run while the alternator is charging so I doubt it's that. Still on my original starter with 140k miles and I don't typically have issues anymore unless my starter battery is low from sitting or my connectors are loose.
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riceandpho
Elite Member
i dont know if you have upgraded to a higher amp alternator yet, but it do require a shorter belt.
GATES K070825HD
im using this belt now since my alternator has a smaller pulley. also my voltage dips to the low 12.5 when my rpm is at 500, so it dosent charge at that low, these alternator like to see 800.
i think there is a 3 to 1 ratio for rpm calculation they used.
