New bad alternator

[wilkusmcrecon]

Well I was able to get a alternator here in Alaska only to find out its from Spider Marine, and the seller tells me I must deal directly with SPIDER MARINE customer service.

Had my batteries checked (OKAY), everything ran fine before the Belt Tennsioner went tits up and ate the alternator belt. While it was running with the new alternator everything was fine until I watched the volt meter slowly drop from green to yellow even at 1900rpms it showed no charge, by the time I got it home I was almost to red. Tried to restart and my volt meter was in the red.

I was able to charge up my MIL batteries and they are fine but they were ran down.

I was lucky in install that I figured the increase in pulley size would make up the difference in alternator size and it did. I was able to keep the original belt to beat. I took the time to make it look like it was meant to be there then I had to take it all apart. JUST CAN'T GET A BREAK

 

[Tinstar]

The larger the alternator pulley size, the slower it turns.
I assume you went with a modern alternator instead of the original design.
They have to turn a certain minimum rpm to charge. That's the way I understand it anyway.

 

[Suprman]

If its a military alternator and the excite wire is not properly connected it will just spin and not make any power. This does not usually apply to civilian alternator though.

 

[wilkusmcrecon]

The larger the alternator pulley size, the slower it turns.
I assume you went with a modern alternator instead of the original design.
They have to turn a certain minimum rpm to charge. That's the way I understand it anyway.

Yep, I went to a 24 Volt Delco clone 23Si 70 amp. I kept the original Mil alternator as a backup still looking for a pulley that will work. I had the new alternator checked it was fine.

Seems I have a battery problem with the four large white military batteries with date of service 2011. When I picked up the truck I was unaware that only two where setup, one of the other pairs were no good according to Those Military guys.

Not sure if these can be saved or I need to replace them. I hope they can be saved. If not I was told all I need is two good 12 volt batteries and she will run fine. Need to find out what works if I need to replace them?

Chris W

 

[Suprman]

If you have Hawkers and they are weak, you can try to give them a charge. In a well vented area, you can charge them individually. They need at least a 20 amp charger. They are AGM batteries. If you start smelling rotten eggs then take it off charge its venting.

 

[Tinstar]

Their at their life limit with a 2011 date.
Definitely try a brute charge and see if they come back.

Two batteries will be fine in summer, but may not be enough in the dead of winter.
Quite a number of threads about it.

Contact SS member 74M35A2.
He might be able to help you with the pulley.

 

[gimpyrobb]

Get a pair of 8d batteries and never look back.

 

[simp5782]

Get a pair of 8d batteries and never look back.

Don't say that. Cause between Clint's little cheerleader for the alternator swaps. I actually got an alternator that wasn't up to the task and kept killing 8D's while I was in North Carolina. but then again, I could screw up an Abrams in a few minutes I am sure.

 

[74M35A2]

You were running 5 electric fans and the alternator reached its temp limit. The temp limit is set by Delco, not me. Not really on board with "I got a bad alternator from Clint". I believe a path of fresh air that you gave it improved the situation. Cracked fan too I believe, I will refund the $ you paid for a local fan, apology, likely happened during shipping. MSRP on that alternator is $865, you got a great deal.

I only supply pulleys to folks who buy alts from me, otherwise I don't know who has what and may get blamed for their setup, bad batts, belt lengths, etc. Nobody wants to face the music of updating their batteries. As long as they start the truck, they say they are good. Not true. I basically won't even talk to anybody unless their batteries are less than 5 years old, after that they become an anchor around the alternators neck and choke out any idle output it may have, even if voltage shows OK, the batteries are still sucking the amperage continuously. A healthy battery recovers after start very quickly, and current to the battery from the alternator drops to zero, leaving all alternator current available to support the vehicle, even at idle. Everybody always blames alternators. Let me know the actual test CCA result of each battery vs it's label rating and we'll talk. "Tested good" means nothing at all. Battery life is chemistry inside, which is accelerated every time a battery is allowed to fully discharge. Trickle charging during off times can help extend to 5 years by minimizing the reaction inside, but not forever. Time kills everything, bar none.

Pulley diameter is a difficult balance. Of course, a smaller one will spin faster for more idle output, but you reach a limit where there is not enough belt wrap diameter and the belt will slip under full alternator load, especially when wet or fully loaded. This is why you will not see a high output alternator with a tiny pulley on it. It requires more belt wrap to transfer the 5100kW of energy into the rotor shaft. That is a real number for a 130A rated 24v alternator at full cold output (177A x 28.8v). Nearly 10hp once you factor in an additional factor of 60% efficiency. The 400A unit on some MRAP ISL motors is a 12 groove belt. Not 8, not 10, 12 grooves. That pulley is also not the diameter of a film container.

Lots of complaints of Spider Marine. Sorry to hear that. All one should need is two new group 31's, and a Delco clone alt, no battery chargers required. $400 or less refreshes the entire system.

Everything is just math. Emotions are in a separate box.

 

[simp5782]

You were running 5 electric fans and the alternator reached its temp limit. The temp limit is set by Delco, not me. Not really on board with "I got a bad alternator from Clint". I believe a path of fresh air that you gave it improved the situation. Cracked fan too I believe, I will refund the $ you paid for a local fan, apology, likely happened during shipping. MSRP on that alternator is $865, you got a great deal.

I only supply pulleys to folks who buy alts from me, otherwise I don't know who has what and may get blamed for their setup, bad batts, belt lengths, etc. Nobody wants to face the music of updating their batteries. As long as they start the truck, they say they are good. Not true. I basically won't even talk to anybody unless their batteries are less than 5 years old, after that they become an anchor around the alternators neck and choke out any idle output it may have, even if voltage shows OK, the batteries are still sucking the amperage continuously. A healthy battery recovers after start very quickly, and current to the battery from the alternator drops to zero, leaving all alternator current available to support the vehicle, even at idle. Everybody always blames alternators. Let me know the actual test CCA result of each battery vs it's label rating and we'll talk. "Tested good" means nothing at all. Battery life is chemistry inside, which is accelerated every time a battery is allowed to fully discharge. Trickle charging during off times can help extend to 5 years by minimizing the reaction inside, but not forever. Time kills everything, bar none.

Pulley diameter is a difficult balance. Of course, a smaller one will spin faster for more idle output, but you reach a limit where there is not enough belt wrap diameter and the belt will slip under full alternator load, especially when wet or fully loaded. This is why you will not see a high output alternator with a tiny pulley on it. It requires more belt wrap to transfer the 5100kW of energy into the rotor shaft. That is a real number for a 130A rated 24v alternator at full cold output (177A x 28.8v). Nearly 10hp once you factor in an additional factor of 60% efficiency. The 400A unit on some MRAP ISL motors is a 12 groove belt. Not 8, not 10, 12 grooves. That pulley is also not the diameter of a film container.

Lots of complaints of Spider Marine. Sorry to hear that. All one should need is two new group 31's, and a Delco clone alt, no battery chargers required. $400 or less refreshes the entire system.

Everything is just math. Emotions are in a separate box.

Calm down cousin eddy. Never said it was bad. Just not up to the task. I dont agree with a 200 degree alternator though on an engine. Underhood temps can see 220 or more while shutoff. Not to mention 8 inches from an exhaust manifold. Noone has ever put that kind of load on one. And 5 fans only draw 30 amps. Ac blower and compressor draws 21.

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[74M35A2]

You're fine. You did not say it was me directly, I bent those words a little. Probably why Delco Remy is closing it's doors. Borg Warner bought them and moved all the starter/alternator people to electric vehicle traction motor group, envisioning vehicles to not require starter/alternators soon.