Gonna go out on a limb and assume... (1 Viewer)

[LandLocked93]

...that I'm looking at new voltage reg on the alt?
I'm seeing a regular 14.1V to 14.6V while running.
The last time it dipped into the 13's (13.96) was on a long haul to Black Bear or somewhere similar.
Also seeing minor weeping from the caps on both engine bay deep cycle batts.
2 years ago 13.3 to 13.8 was a regular measure.

What's the forum consensus?

 

[LongDuck]

Could be batteries not holding a charge, therefore alternator is working overtime to get them charged up again. I've noticed this when first starting out after the LandCruiser has been sitting dormant for awhile. After about 10-15min of driving, the charge rate drops down to 13.8v, where it belongs.

 

[93yotasr5]

How old are the batteries? Pretty easy to take them in and have em tested before removing the alternator and getting it tested.

 

[BreezyF]

No expert here but it could be the capacity of the batteries depending how old they are. Idk if you’ve have or have the need to invest in one but I have a Advance Auto Parts - Down for Maintenance - https://shop.advanceautoparts.com/p/schumacher-200a-6v-12v-automatic-wheel-charger-and-engine-starter-40a-boost-battery-and-alternator-tester-sc1309/11824392-p?product_channel=local&store=4460&adtype=pla&product_channel=local&store_code=4460&gbraid=0AAAAAD05GhXSLYBI_SQnHBlXDGO1zUbkb&gbraid=0AAAAAD05GhXSLYBI_SQnHBlXDGO1zUbkb&gclid=Cj0KCQjwla-hBhD7ARIsAM9tQKsU5q6uYY3Ske0k7BYU99KenFFhTF-tfNa8O7fKGn-tsecCM1EisdAaAvqyEALw_wcB&gclsrc=aw.ds
Which will show the health and percentage of the battery as well as be able to test if the alternator is good. As well as jump start, charge, and trickle charge standard and AGM batteries. I love mine and might be something to look into to diagnose your specific problem as well as have it for the future. Just my .02

 

[LandLocked93]

Could be batteries not holding a charge, therefore alternator is working overtime to get them charged up again. I've noticed this when first starting out after the LandCruiser has been sitting dormant for awhile. After about 10-15min of driving, the charge rate drops down to 13.8v, where it belongs.

Their resting voltage is about 12.5V each. They are Interstate 34s, maybe 2 years old or so. The profile is nominal - high charge rate at first, then it drops to <1A after a little while. As the charge rate dropped, so too would the voltage output. This not happening now tho. My concern is that the alt still registers over 14v output when they are fully charged.

 

[LandLocked93]

How old are the batteries? Pretty easy to take them in and have em tested before removing the alternator and getting it tested.

About 2 yrs old, from new. The rest voltage is 12.5V so I don't think they are going out. Even after 2 weeks of the rig sitting, they still show about 12.3 to 12.4V at rest. Only parasitic draw is the alarm when armed.

 

[LandLocked93]

No expert here but it could be the capacity of the batteries depending how old they are. Idk if you’ve have or have the need to invest in one but I have a Advance Auto Parts - Down for Maintenance - https://shop.advanceautoparts.com/p/schumacher-200a-6v-12v-automatic-wheel-charger-and-engine-starter-40a-boost-battery-and-alternator-tester-sc1309/11824392-p?product_channel=local&store=4460&adtype=pla&product_channel=local&store_code=4460&gbraid=0AAAAAD05GhXSLYBI_SQnHBlXDGO1zUbkb&gbraid=0AAAAAD05GhXSLYBI_SQnHBlXDGO1zUbkb&gclid=Cj0KCQjwla-hBhD7ARIsAM9tQKsU5q6uYY3Ske0k7BYU99KenFFhTF-tfNa8O7fKGn-tsecCM1EisdAaAvqyEALw_wcB&gclsrc=aw.ds
Which will show the health and percentage of the battery as well as be able to test if the alternator is good. As well as jump start, charge, and trickle charge standard and AGM batteries. I love mine and might be something to look into to diagnose your specific problem as well as have it for the future. Just my .02

If I lived in a house and had a garage I'd have something like that.

 

[mudgudgeon]

About 2 yrs old, from new. The rest voltage is 12.5V so I don't think they are going out. Even after 2 weeks of the rig sitting, they still show about 12.3 to 12.4V at rest. Only parasitic draw is the alarm when armed.

What's the voltage read while starting?
Under load, the voltage shouldn't drop below 12 volts.
I've had batteries that held a charge, showed 12 volts plus, but during starting were down to 10.5 or less. Dead cell in the battery.

 

[BILT4ME]

I recently had a similar issue. My alternator was a O'Reilly's reman that was in there for 8 years. It got to the point it was charging well over 14 100% of the time.
Finally, on a trip home of about 300 miles, the alternator light came on while driving. I shut it down, restarted and the light was off. It came on again during the same trip, so I replaced it with a Toyota reman an it's back in range.

I had times before I replaced it that the alternator light would come on right after starting and I would have to rev it over 4000 RPM to excite the stator again and it would be good for a few days.

I have a UltraGauge specifically to monitor my voltages and it allowed me to watch what's happening.

Replace your alternator, as the regulator is dying.

 

[LandLocked93]

What's the voltage read while starting?
Under load, the voltage shouldn't drop below 12 volts.
I've had batteries that held a charge, showed 12 volts plus, but during starting were down to 10.5 or less. Dead cell in the battery.

Ok, I'll look at that this weekend. I've watched for that before tho. The crank time is less than 2 seconds. My monitors might get 2, significantly disparate readings during that time. Haven't really trusted the values displayed but will admit that 11's are displayed most times. 11.80 is lowest I saw.
Tho one caveat to this is that the measurements I bothered to take were on first crank after the rig's been sitting for 10days+.
I'll check it on a trail run instead and see what's what.

 

[LandLocked93]

How old are the batteries? Pretty easy to take them in and have em tested before removing the alternator and getting it tested.

You just reminded me of a bracket and alt residing in the parts pile somewhere.
Wouldn't hurt to swap that in and see if anything changes/improves, yeah?

 

[93yotasr5]

Definitely not going to hurt to try it out