Alternate Alternator Selection

[GeneralDisorder]

Keep the manual disconnect - it's very convenient for working on the truck. And keep the NATO slave receptacle. And for that matter keep the front glad hands. Everyone likes to delete this stuff but it makes jump starting and recovery a PITA for the rest of our community. It's pretty often that guys will have some sort of malfunction and need help from this forum or the Facebook groups and without those items it just make the job harder. Being able to hook up a tow-bar and have working brakes and not have to cage the parking brakes, etc is very handy. Sure you can (and might have to) call a commercial class 8 wrecker but it will cost you 4 digits and potentially 5 and they are VERY likely to break your truck. They have no idea what they are doing with our trucks. You are much better off if the community can rescue you.

 

[hike]

Yes on the 12v battery. It seems prudent to have backup in case there's a failure of the victrons while driving.

No, I removed the relay so there's no aux contacts to run the dash light. I was just thinking there could be a test connection for the switch outside by connecting 1008 to 1855. It's of no use really, just Xmas lights. It'll just be open circuited as shown now.

Only the manual disco remains. I'm on the fence about that as well for the reasons you gave, but it is possible to lock it closed. It's a nice safety device when working in the engine comp. If it fails, contacts failure, then I'd have a possible issue but that seems low probability. Idk
View attachment 918072

We dropped the 12v backfeed, though will have 2-banks of 2-31's separated by a battery combiner which will allow the second bank to start assist, if need.

We removed the LBCD and battery relay disconnects as you did, though brought the 24v alternator to the battery side of the manual disconnect. Batteries and alternator always connected—

 

[MatthewWBailey]

Keep the manual disconnect - it's very convenient for working on the truck. And keep the NATO slave receptacle. And for that matter keep the front glad hands. Everyone likes to delete this stuff but it makes jump starting and recovery a PITA for the rest of our community. It's pretty often that guys will have some sort of malfunction and need help from this forum or the Facebook groups and without those items it just make the job harder. Being able to hook up a tow-bar and have working brakes and not have to cage the parking brakes, etc is very handy. Sure you can (and might have to) call a commercial class 8 wrecker but it will cost you 4 digits and potentially 5 and they are VERY likely to break your truck. They have no idea what they are doing with our trucks. You are much better off if the community can rescue you.

Yeah I'm not deleting anything that makes my life easier. I've used that front gladhand a few dozen times already just to release the brakes. Pretty convenient! Plus I have the gladhand adapter and hose for airing up tires manually (if needed) since my CTIS is out of order. I have 2 sets of nato slave receptacle hookups, one big honking set for nato-to-nato connection, 20' 4/0 cable that was a used find on eBay, if I ever need a jump from another lmtv. The other is just a nato plug with 1' long cable and bare battery connections I use for jumping with my jump-and-carry unit, or for external charging on demand.

 

[MatthewWBailey]

We dropped the 12v backfeed, though will have 2-banks of 2-31's separated by a battery combiner which will allow the second bank to start assist, if need.

We removed the LBCD and battery relay disconnects as you did, though brought the 24v alternator to the battery side of the manual disconnect. Batteries and alternator always connected—

Yes I like that arrangement too. The separate 12v battery isn't really necessary with 2 victrons powering up the 12v side. I'm always thinking about what happens when stuff breaks, while driving. The wires are already there and it's no extra cost to leave the battery there.

 

[Ronmar]

the manual disconnect is handy for maintenance. i havn't added one, but I will when I get my final configuration sorted out. As for backup, that is what the house battery cross tie will be for

 

[MatthewWBailey]

I got tired of typing my dreams and just started it up. The "charging system" light works as expected. Tested it firsts and it's good. See pics of diode assembly. I appreciate you guys making this happen🫡

Alt produced 99amps with the AIH on and batteries a little drained(only 2). Then with AIH off it went to 20A and 28.02v. Not much movement in voltage. Batts were tracking 0.1v less than at the alt terminal.

new serpentine was fine but was close to short. My old belt was 80" and I mistakenly used the parts spreadsheet to measure from and that says 78.25". The one on there now is 68-5/8". I've got 1/4" of gap on the top tensioner limit. Close.

now onto the PDP board. Mine doesn't look like the manual but I was going to use the radio CB20 as a power feed for the victrons.

New alt install first run. Post start, AIH on. No lbcd, No battery disc relay.

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New alt install first run. Post start, AIH off. High idle

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[MatthewWBailey]

Finally wired up my 12v victrons. I already had 2 of these 24/12-20 units with Bluetooth, for another project. I couldn't really find a good breaker to hook them to so I just added a 30a fuse off of X3 and paralleled the 2 outputs onto X2. The Bluetooth setup allows for monitoring and changing settings.

set the low input cutout for both to 22v and the reset to 27.5v. That way, these won't turn on until the starter's done and then AIH finishes, then a delay for voltage to return to 28. Should act like a reactive timer function.

There's no room for these inside so they're attached to the center console. I'm making a stainless cover for the center console foot area to house these and some other things later so these will be open for now. Helps with Bluetooth anyway.

With everything 12v I could turn on at once, I was only pulling 14.8 amps. So 2 units is definitely overkill.

 

[MatthewWBailey]

Update. I'm posting here on the alt driven tach signal bc I've no clue where else to post. There's a lot of various tach threads. I hooked up this IssPro tach, using pulses per rev. Works except the PPR numbers didn't calibrate at all. Assuming my idle/fast idle is 700/1350, something is off. I measure the pulleys at 3" and 7.5" which is 2.5 ratio. Alt manual says 10pulses per rev. That's 25 ppr on the guage setting. At that setting, idle reads at 400 fast idle 800. So I lowered to 16ppr. Now I'm at 650/1250. I assume those are supposed to be 700/1350 per ECM program? So, Either the alt is only 6 pulses per rev or my tape measure is metric. I guess I need to dig out my strobe GDI .

 

[reb87]

I really appreciate the info in this thread. I picked up this 24v alternator https://www.amazon.com/gp/aw/d/B0BFT4416K?psc=1&ref=ppx_pop_mob_b_asin_title
Used one of the 100 amp bussmann equalizers
P/N 21100E00
And dumped the dual voltage junk on my 2004 m1088a1 I just drilled out the top mounting bracket hole and made a bottom arm to hook to the new alternator. So far it’s working great.

 

[MatthewWBailey]

I really appreciate the info in this thread. I picked up this 24v alternator https://www.amazon.com/gp/aw/d/B0BFT4416K?psc=1&ref=ppx_pop_mob_b_asin_title
Used one of the 100 amp bussmann equalizers
P/N 21100E00
And dumped the dual voltage junk on my 2004 m1088a1 I just drilled out the top mounting bracket hole and made a bottom arm to hook to the new alternator. So far it’s working great.

So that is the exact same 28SI Delco alternator as mine, only yours is J180 mount. Your number below in red. Nice it's only $130!!

 

[MatthewWBailey]

Update. I'm posting here on the alt driven tach signal bc I've no clue where else to post. There's a lot of various tach threads. I hooked up this IssPro tach, using pulses per rev. Works except the PPR numbers didn't calibrate at all. Assuming my idle/fast idle is 700/1350, something is off. I measure the pulleys at 3" and 7.5" which is 2.5 ratio. Alt manual says 10pulses per rev. That's 25 ppr on the guage setting. At that setting, idle reads at 400 fast idle 800. So I lowered to 16ppr. Now I'm at 650/1250. I assume those are supposed to be 700/1350 per ECM program? So, Either the alt is only 6 pulses per rev or my tape measure is metric. I guess I need to dig out my strobe GDI .View attachment 922116

Final update on this. I got this unit recalibrated using the strobe. I'm dead on 700 at idle and 1350 at fast idle, matching the strobe. The tach settings had to be massaged to 14ppr. Eventually I'll add that Blue Fire thing to read all that ECM info but this works great for now as a tach off the Alt "R" terminal.

 

[reb87]

So that is the exact same 28SI Delco alternator as mine, only yours is J180 mount. Your number below in red. Nice it's only $130!!View attachment 934083

It was very easy to mount and I was able to use the original belt

 

[MatthewWBailey]

More possibilities emerge! After researching the Denso alts, I was unable to verify pad mount dimensions. Typical since auto parts are almost exclusively about make and model of vehicle. ( I put the Delco on there in March).

I had identified a cat part number for an Alt that fits a 3126 as 272-1889. That led me to a Denso unit with interchange # of 101210-9010. But no one advertises the pad dimensions fully & The pad on a 3126 A1 truck is 4.25" x 7.5" for the inner set of holes. (7.45") I took a chance on the Delco Remy Alt and it fit perfectly. So, why not try again? I need a spare anyway. So, The 101210-9010 alt I found is a 150Amp, 24v and $437 on eBay free shipping. Received it today and it fits. Holes are 4.25 x 7.5 just like the Delco.

Definite upgrade from 110 to 150 but still padmount!

now this Denso only has B+ and R terminals whereas the smaller Delco has S, I, R and B+. Minor impact since R can be used to drive the "charge system" light if desired.

this particular unit is a replacement on a slew of Cat machines including a C7.1 engine, which is why I took the chance.

Anyway, another option for padmount if desired

 

[aw113sgte]

It's been a while so take with a grain of salt, but I thought there were two standards for pad mounts and we have the mounting holes for both.

 

[Keith Knight]

So how does that one attach to the 3126? Do yo remove our adapter plate and that mounts directly to the block?

 

[hike]

So how does that one attach to the 3126? Do yo remove our adapter plate and that mounts directly to the block?

Right—

 

[MatthewWBailey]

It's been a while so take with a grain of salt, but I thought there were two standards for pad mounts and we have the mounting holes for both.

Yes, There's an extra set of holes on the left side that are 5.25" I believe, that's what the J180 plate attaches too. However, I've found no pad mounts, SO FAR, that fit to that set of holes.

 

[MatthewWBailey]

So how does that one attach to the 3126? Do yo remove our adapter plate and that mounts directly to the block?

Yes this adapter plate comes off



This base plate is part of the base 3126 engine. I believe it has its own Cat part #. It's curved for a reason

 

[Keith Knight]

So the belt would be shorter as well.

 

[MatthewWBailey]

So the belt would be shorter as well.

Yes the new belt is now a NAPA 80708 71-5/16" . That puts the tensioner right in the middle of its range. (The one from the parts spreadsheet is 80774 77-3/4" when using the J180 mount). So it's now ~6-1/4" shorter