Aftermarket alternator?

[THAW]

Correct. It’s plugged into the OBD port. I don’t know where it pulls it’s data from, but the analytical process takes quite a while. Since I don’t understand how automotive computers work, I’m skeptical. On the other hand, the new batteries need to be plugged in most of the time, even when the jeep is driven 30 to 40 minutes three or four days per week, although there is very little parasitic drain (mostly from the Genesis relay, I think).

The Innova 5610 has to be set up to read each vehicle. If it’s set up for, say, a Ford truck, then plugged into the Jeep OBD port, it won’t be able to connect, because it's speaking a different language or looking for different readings. When you properly enter year, make, and model, it asks which engine you have — so it “knew“ it was connected to a 2019 Wrangler with the 3.6, and it cycled through all the vehicle system checks. Maybe it’s just a light show?

I think I’ll give the guys at Genesis a call. I had hoped to upgrade to their new top plate, as the new system has almost zero parasitic drain, but it’s $500, bringing the total genesis and battery cost to about $2100… There is no discount for folks who have been suffering with the original Genesis system for years. (I was hoping there might be a $200 or $250 rebate for returning the old top. They’d still probably be making $150 or $200 on the sale. No such luck, so I’m reluctant to bend over and grab my ankles.)

I assume the Innova 5610 does meaningful testing on some systems, but based on what I've seen of it I'm highly skeptical it is properly assessing your alternator. I believe it doesn't work well with smart alternators, and could have given you a false positive for failure.

JScan is the best DIY way to properly assess the alternator.

A possible option for Genesis gen2 hub replacement: https://www.renogy.com/products/renogy-12v-24v-ip67-50a-dc-dc-battery-charger-with-mppt. It would take some wiring and app configuration.

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[wcjeep]

Could go with Premier Power Welder. Their alternators are Hot rated. Most alternators are cold rated. As Alternators heat up their power output goes down. Meaning Premier Power Welder alternators are very powerful. Have a Premier on my YJ.

https://premierpowerwelder.com/shop...-power-welder/?searchid=30548&search_query=Jl

 

[mwilk012]

Correct. It’s plugged into the OBD port. I don’t know where it pulls it’s data from, but the analytical process takes quite a while. Since I don’t understand how automotive computers work, I’m skeptical. On the other hand, the new batteries need to be plugged in most of the time, even when the jeep is driven 30 to 40 minutes three or four days per week, although there is very little parasitic drain (mostly from the Genesis relay, I think).

The Innova 5610 has to be set up to read each vehicle. If it’s set up for, say, a Ford truck, then plugged into the Jeep OBD port, it won’t be able to connect, because it's speaking a different language or looking for different readings. When you properly enter year, make, and model, it asks which engine you have — so it “knew“ it was connected to a 2019 Wrangler with the 3.6, and it cycled through all the vehicle system checks. Maybe it’s just a light show?

I think I’ll give the guys at Genesis a call. I had hoped to upgrade to their new top plate, as the new system has almost zero parasitic drain, but it’s $500, bringing the total genesis and battery cost to about $2100… There is no discount for folks who have been suffering with the original Genesis system for years. (I was hoping there might be a $200 or $250 rebate for returning the old top. They’d still probably be making $150 or $200 on the sale. No such luck, so I’m reluctant to bend over and grab my ankles.)

How are you measuring parasitic drain?

 

[Whaler27]

How are you measuring parasitic drain?

I took the jeep to a local auto-electric shop. He connected a meter, shut the hood, and waited for the brain (ECU?) to shut down, then read the current draw. I can’t recall the the number, but it was only slightly higher than expected, which he seemed to think was consistent with the drain he’d expect from the Genesis relay. It was a ten minute exercise about two years ago, so I’m fuzzy on the details.

 

[mwilk012]

I took the jeep to a local auto-electric shop. He connected a meter, shut the hood, and waited for the brain (ECU?) to shut down, then read the current draw. I can’t recall the the number, but it was only slightly higher than expected, which he seemed to think was consistent with the drain he’d expect from the Genesis relay. It was a ten minute exercise about two years ago, so I’m fuzzy on the details.

That number is very important, also that was 2 years ago.

 

[Whaler27]

That number is very important, also that was 2 years ago.

Yes on both counts. I’ve done nothing more to the jeep, and I don’t see evidence that the condition has worsened, so I assume I’m in the same boat I was in then. I’m just driving the jeep more without seeing improvement in the rate of battery drain.

If I have the jeep disconnected from the charger for a week because I’m using it every day or every other to run 15-20 mile errand loops, it will charge for almost a full day on a 10 amp Noco charger before transitioning into float status.

Here’s a stupid question: with all the tricky charging/programming parameters, how do you test the alternator function?

 

[Mguy]

Yes on both counts. I’ve done nothing more to the jeep, and I don’t see evidence that the condition has worsened, so I assume I’m in the same boat I was in then. I’m just driving the jeep more without seeing improvement in the rate of battery drain.

If I have the jeep disconnected from the charger for a week because I’m using it every day or every other to run 15-20 mile errand loops, it will charge for almost a full day on a 10 amp Noco charger before transitioning into float status.

Here’s a stupid question: with all the tricky charging/programming parameters, how do you test the alternator function?

Your question isn’t stupid, but the rest of your post . . . .

 

[THAW]

Your question isn’t stupid, but the rest of your post . . . .

This post doesn't even have a good question...

 

[mwilk012]

Why do you think there is a problem with anything other than your old batteries that are constantly being charged? What problem do you even have?

To properly test a PCM regulated alternator you would need access to a scan tool to read alternator field command % and an oscilloscope to check that the commanded signal is present at the alternator. For internally regulated LIN bus communicating alternators, check the command %, check the output, and if that fails verify the wiring continuity from pcm to alternator.

 

[Jeep Wick]

My 2019 JLUR with the 3.6 just killed it’s second pair of batteries since I installed the Genesis dual battery system less than 10,000 miles ago. The jeep has less than 15,000 miles on it, so it’s spent most of its life in my shop on a Noco smart charger.

Last week the check engine light came on, so I connected a diagnostic tool to the OBD port to read and clear the code. The code was insignificant and unrelated to the electrical system, but I decided to do a full diagnostic run while I was hooked up. One of the diagnostic routines is an alternator check. The code reader tracks the jeep at idle for a while, then it instructs you to bring the RPMs between 2000 and 3500 rpms for about 30 seconds, than back to idle. The report said my alternator is in bad shape.

The OEM alternators are stupid expensive. Anybody had good luck with Napa alternatives? They have worked great in other vehicles, but some say Wranglers are too finicky. Thoughts?

Not a fan of NAPA myself. Have you looked at Rockauto? They typically have a few options and reputable brands. You have such low miles!

 

[jaymz]

In my experience, alternator failures aren't terribly common anymore. It wouldn't be my first suspect.

 

[mwilk012]

In my experience, alternator failures aren't terribly common anymore. It wouldn't be my first suspect.

On these alternators we usually see them fail when the “clutch” goes bad and the pulley is just freewheeling. I’ve seen new Mopar alternators last less than 5000 miles before doing the same thing. It’s rough out there for parts.

 

[Whaler27]

Why do you think there is a problem with anything other than your old batteries that are constantly being charged? What problem do you even have?

To properly test a PCM regulated alternator you would need access to a scan tool to read alternator field command % and an oscilloscope to check that the commanded signal is present at the alternator. For internally regulated LIN bus communicating alternators, check the command %, check the output, and if that fails verify the wiring continuity from pcm to alternator.

This set of batteries is brand new. (About two weeks old). They’re healthy Optima Red Tops. (I know… Optima isn’t what it was before the move to mexico, but they're not tired.

 

[mwilk012]

This set of batteries is brand new. (About two weeks old). They’re healthy Optima Red Tops. (I know… Optima isn’t what it was before the move to mexico, but they're not tired.

But what actual problem are you having?

 

[Whaler27]

As I said above,
1) the jeep has killed two sets of batteries in 10,000 miles. That’s an undesirable feature, because batteries are expensive, and

2) Driving the jeep 20 or 30 miles 2 or three days per week is insufficient to keep the batteries anywhere close to fully charged, and

3) Taken together, these challenges, together with the results on the diagnostic tool, suggest there may be something wrong with battery charging.

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