Need Help: Delayed Start on '21 ORP

2021 ORP - 85k miles

The other day I experienced a strange phenomenon when trying to start the vehicle. I hit the ignition button and typically, the engine turns over within ~1 second. The other day it took 3 or 4 seconds to start and sounded like a weak start. On the drive home, I had low voltage. Radio reset a few times (presumably from voltage dropping below a certain threshold).

I have multiple voltage readings (one from the Genesis dual battery set-up which I have had for several years) and one that is from a USB plug in the dash (which I have had for several years). The dash voltmeter typically reads a bit higher than the Genesis display (.2 volts). During the drive, the dash voltmeter showed 14.4 volts, the Genesis was in the 12's. Strange to see that disparity. The Genesis is direct from the battery.

When I got home, I popped the hood, looked at everything. Jiggled the positive and negative cables thinking they might be loose at the terminals but all seemed fine. No corrosion on the terminals. Afterwards, vehicle started just fine. Ran fine for several days with no issue.

Batteries are around 3 years old now, so that could be an issue. Or could it be the alternator? I have also read that it could be a loose ground wire.

I am also using the Voltage Booster Pro for several years to assist as I have the dual AGM batteries.

Planning to take the 4Runner on a long road trip next week and trying to get this issue resolved in advance. Pregnant wife does not want to be stranded on the side of the road (me either if we are being honest)!

 

You can have good voltage at the batteries, but have low amperage. Cold Cranking Amps (CCA) is what gets the engine turning. I would get those batteries load tested and replace if necessary before I started throwing parts at it.

 

Yes - plan to pull them tonight and test them. 2 batteries will run about the same as an alternator, which I would likely do myself.