TheSamba.com :: View topic - 110 amp alternator upgrade for your Subaru conversion CHEAP

Thu Feb 29, 2024 1:14 am

Just did this mod using a 23700AA521 (seems to be the same as 23700AA520). It seemed to be working great until I turned on my headlights tonight. At idle, with the headlights on, the alt light flickers. The belt is tight and the alt voltage output is around 14.2-14.5. I have the GoWesty high-output headlight kit which has a large draw. I love the alternator as it’s charging my lithium house battery and starter battery much better than the old alternator (OE ‘94 Legacy). Not sure what to make of the flicker though.

Thu Feb 29, 2024 8:54 am

Where are you measuring the alternator voltage? If reading it on your Scangauge it should be accurate. If reading it at the alternator itself you may be losing voltage somewhere due to poor connections.

Thu Feb 29, 2024 9:31 am

hansh wrote: Just did this mod using a 23700AA521 (seems to be the same as 23700AA520). It seemed to be working great until I turned on my headlights tonight. At idle, with the headlights on, the alt light flickers. The belt is tight and the alt voltage output is around 14.2-14.5. I have the GoWesty high-output headlight kit which has a large draw. I love the alternator as it’s charging my lithium house battery and starter battery much better than the old alternator (OE ‘94 Legacy). Not sure what to make of the flicker though.

Do you have a headlight relay kit installed? This is probably a must do install for all Vanagons.

Thu Feb 29, 2024 10:43 am

harvgwen wrote: Where are you measuring the alternator voltage? If reading it on your Scangauge it should be accurate. If reading it at the alternator itself you may be losing voltage somewhere due to poor connections.

I’m just using an LED volt meter on the dash where the cigarette lighter used to be. The wires are small, so I see a drop with each additional electrical load, but the background output remains the same when loads are turned off. The volt meter read out shows 13.6-13.8 with just the headlights on, and returns to 14.2-14.6 when lights are turned off (this is fine with me, and the way the old alt displayed too. It’s just the alt light flicker that is new).

mtnhome wrote: Do you have a headlight relay kit installed?

Oh, yes :) The whole kit including relays.

Thu Feb 29, 2024 11:29 am

That should be a good place to take your voltage. The voltage drop with lights on seems a bit much to me (I’m not a professional auto mechanic). Does it go back up when you increase the RPM a little? Some on this forum have been suggesting installing a good ground strap directly from the alternator case to the chassis. I haven’t read about anyone suggesting a larger positive cable from the alternator when upgrading, so presumably the original wire is sufficiently large to take the extra amperage.

Sat Mar 02, 2024 8:13 pm

Because I didn’t have this flickering light with my old, and lower output alternator, I don’t think that the wire gauge should be an issue with this particular problem. Also, I was not seeing low output at the alternator, the dc-dc charger app, or at the voltmeter in the dash (and they all agreed). YET :) I decided to replace the brushes just in case, and we’ll see if it helped. They were well below half worn. It seems to have helped a bit initially, but I think that the brushes need to wear-in before they are at there most efficient. I’ve replaced brushes before, but only on something that had an easily serviceable regulator. This was not quite so easy! I followed this video and it was nearly identical to my Mitsubishi alt. The only real exception was the B+ terminal. Mine had a cap with a nut under it and then the terminal needed to be gently pried off.

Sun Mar 03, 2024 3:17 pm

Victron has a new and improved Dc Dc XS 50 unit avaiable which is 1/3 the size and produces much less heat.

From what I read the stock Subaru Alternator is 90 amp output and from what I read with Victron they want you to have at least twice the alternator than the charger, Is there enough margin to run this or would it cook my Alternator?

Wondering if I need to update my Alternator or use a different Dc Dc charger.

Stacy

Sun Mar 03, 2024 3:28 pm

16CVs wrote: Victron has a new and improved Dc Dc XS 50 unit avaiable which is 1/3 the size and produces much less heat.

From what I read the stock Subaru Alternator is 90 amp output and from what I read with Victron they want you to have at least twice the alternator than the charger, Is there enough margin to run this or would it cook my Alternator?

Wondering if I need to update my Alternator or use a different Dc Dc charger.

Stacy
My EJ22 alternator was 90A. Useless for charging my LFP batteries. I thought the 110A alternator would cope fine - no, not good enough even for the Renogy DCDC50 with the solar on (so only taking a max of 25A). The 130A Tribeca alternator works just fine though, happily giving 45A over and above the normal running current requirements of the van.

Mon Mar 04, 2024 7:25 am

16CVs wrote: Victron has a new and improved Dc Dc XS 50 unit avaiable which is 1/3 the size and produces much less heat.

Oh that is super interesting new product!

I am having to relocate my Redarc 50amp charger externally to my rear vent because it is overheating and throttling.

Mon Mar 04, 2024 9:42 am

1990-94 legacy alternator is 70 amps. Late model vanagon alternator is 90 amps.

Mon Mar 04, 2024 10:36 am

I'm running the 110 A direct swap on a 1990 EJ22. The alternator came from OReily's, and one has already failed which got replaced free with their "lifetime warranty".

I'm looking for a higher quality replacement than FLAPS parts or eBay used units. Has anyone tried these guys?

https://www.qualitypowerauto.com/catalog.php?item=291

Fri Jul 18, 2025 6:39 pm

Any need to consider upgrading alternator to starter wiring when installing a Tribeca alternator with a Subaru harness?

Fri Jul 18, 2025 6:45 pm

I did that because it was cleaner install for my DC-DC charger. If you’re not pulling any extra power from the starter stud then I don’t think there is any reason to upgrade the wiring.

Fri Jul 18, 2025 7:14 pm

WillRB wrote: Any need to consider upgrading alternator to starter wiring when installing a Tribeca alternator with a Subaru harness?
I did. New, larger gauge wire with no resistance from decades of use seemed like a no brainer.
The main lead from the battery terminates at the starter so you are directly improving conductivity to the battery for charging.

Sun Aug 03, 2025 2:05 pm

Changed out my alternator to starter wiring this weekend. I didn’t realize how undersized my Subaru alternator wiring was. I had mistakenly assumed the two terminals (8 awg?) at the alternator were both to my starter. Turns out only one was.

I had a lot of two wire 4 awg harness left over from my dometic rtx install. Because I had it sitting around i ended up bundling the two wires together to create a 2 x 4awg feed. Noticed a significant improvement in voltage (0.6-0.7 V) both at the starter battery and my ancillary battery.

Moral of the story upgrading your alternator to starter wiring is a very good idea.

Sat Sep 13, 2025 7:10 pm

Hello friends with a swap!

I've been reading through the thread and I cannot find a definite answer...

I'm looking for the Subaru part number for the 130A alternator that fits an EJ22 phase 1 (Legacy 1992). Easiest cleanest physical drop-in unit. I have AC compressor if that matters.

Looks like the Tribeca H6 alternator fits from 2008-09, but listings are confusing online showing some fitting 2008-2014.

Looks like 23700AA620 is 130A 2010-2014
23700AA580 is also 130A, 2008-2009

To avoid mistakes, I'm looking for the part number only that YOU used in this case.

Thank you!

Alika

Sat Sep 13, 2025 7:36 pm

Aloha!

I can finally help you for once! I will try to find the part number tomorrow. I looked at eBay listing 5 years ago and the title only says 08-09. I took a photo when I got it but it’s only shows 601-50199 on the vendors tag attached to alternator.

I’m also a phase 1 EJ22e. Physically I don’t think there was any difference besides the wiring connector.

Sat Sep 13, 2025 8:37 pm

The one that I documented was from '10+. It was installed on a phase 1 ej22.

Sat Sep 13, 2025 10:59 pm

shagginwagon83 wrote: Aloha!

I can finally help you for once! I will try to find the part number tomorrow. I looked at eBay listing 5 years ago and the title only says 08-09. I took a photo when I got it but it’s only shows 601-50199 on the vendors tag attached to alternator.

I’m also a phase 1 EJ22e. Physically I don’t think there was any difference besides the wiring connector.

Aloha my friend!

I'd love the part number if you can find it :)

syncrodoka wrote: The one that I documented was from '10+. It was installed on a phase 1 ej22.

And which part number was that please?

Sun Sep 14, 2025 6:29 am

This is the 130A alternator part number I purchased and installed on my EJ25 from a 2000 Outback. Alternator 400-48261 (AR102244 ) for Subaru Legacy 10-11. Hope this helps you.