Voltage Irregularities HELP (1 Viewer)

[SETXCruiser]

I have been dealing with a peculiar issue with my 2006 LC. At random times the voltage while driving around won’t get above 12.9v and will drop all the way to 11.9v at idle for a split second. But what has me puzzled is I can hop in the car and drive all the way to work and the voltage never gets below 13.6v. Is this indicative of an alternator on its way out? I don’t think it’s a wiring issue because everything looks perfect on the battery terminals. Car has 131k on the clock.

When I got home last night:

The next day:

 

[smug01]

I had the same issue with my 2006 with 124k miles for some time. Finally, my alternator just refused to keep up on a long trip and my battery died due to lack of charge, even though I didn’t have an alternator warning light. Looks like you alternator is in its way out.

I replaced mine with a OEM rebuild and voltage is sold and seems to have fixed the issue.

 

[SETXCruiser]

I had the same issue with my 2006 with 124k miles for some time. Finally, my alternator just refused to keep up on a long trip and my battery died due to lack of charge, even though I didn’t have an alternator warning light. Looks like you alternator is in its way out.

I replaced mine with a OEM rebuild and voltage is sold and seems to have fixed the issue.

Thanks for the response. I am looking at doing the alternator myself so I can get the proper OEM one. Did you do it yourself?

 

[OEMGUY0720]

Maybe this can help: Alternator Voltage Booster - https://forum.ih8mud.com/threads/alternator-voltage-booster.503895/page-4#post-13744233

 

[BnvS]

Aaah I had this similar issue in my 2006 Tundra 4.7l. The voltage meter in dash was fluctuating a bit and in my case battery light in my did come on a few times. I just replaced the Alternator and the issue resolved itself. Got steady voltage in the middle of the voltage meter range.

Also if you are replacing your Alternator try going from the 125Amp (iirc) one I think most 100's have to a 150A version that Sequoia's and Tundra's have. There is some modifications you have to do but probably worth the effort.

 

[smug01]

Thanks for the response. I am looking at doing the alternator myself so I can get the proper OEM one. Did you do it yourself?

Yep, did it myself. Also replaced the serpentine belt while in there since it comes off pretty much anyways to get to the alternator. Not a terrible job but tight with the radiator in there. I left the radiator in, coolant hoses intact, but had to move the power steering pump to get access. Took me much of a day due to some stuck bolts, but overall wasnt too bad. Unlike earlier 100s, the 2006+ have a third stud that the alternator fastens to with a 12mm nut. That one was really stuck on mine and I ended up backing out the entire stud with the alternator to get it out.

 

[smug01]

Oh, and if you loosen the fan shroud and remove the skid plate under the engine, you can get the alternator out and replaced through the bottom of the engine compartment.

 

[BnvS]

Oh, and if you loosen the fan shroud and remove the skid plate under the engine, you can get the alternator out and replaced through the bottom of the engine compartment.

Yeah this is what I did as well.. its a little arm twisting to get the alternator from the bottom. But it can be done. IIRC you will still have to loosen the power steering pump though.