Dual Alternators

[motorbreath53]

Hello Gentlemen...

Forgive me if this is a question that has been asked, but i've used the search engine, and sniffed through the FAQ... notta.... so...

My 94 IDI truck serves as my desert tow rig/camper. I would like to add a onboard air compressor, bigger battery system for the slide in camper (fixed mounted), a gasoline fuel tank and filler station pump, and some other electrical goodies...

Since I was adding more batteries, and more draw I was considering adding a second alternator.


Anybody running dual alternators on their 7.3 IDI that has some pics and part numbers of what they did?

This site kicks ass so far... and thanks in advance for you guy's time...

 

[razorback]

most people on here upgrade to the 130 or 200 amp 3g alt.. do a search and there is plenty of info/write ups on how to do it.

 

[Andylad13]

its better to upgrade to a bigger alternator, and leave any potential space for a belt driven air compressor under the hood for your air needs.

 

[motorbreath53]

The compressor will most likely be a freestanding unit under the fenderwell in the back... but I will look into the 200amp... The idea of relying on one alternator still concerns me a bit... I don't wanna be stuck in BFE with a dead alternator that is tough to find either...

thanks for the replies guys... I appreciate the help.

 

[Andylad13]

there is really nothing to be worried about like that, i mean stuff happens and you can only be prepared for so much. what if your engine blew up, and didnt have a spare in the bed with all the tools to put it in right on the spot, youd be stuck anyways. alternators go bad eventually, if you buy new and it can handle what you want, you'll be fine for years to come.

a 200 amp alternator and a high rated power inverter will handle a 110v tool at 15 amps. if you are still concerned for handling big tools and what not, why not carry a generator, or have a gas powered air compressor?

please know im not trying to tell you that 2 alternaters is a bad idea, i just dont think that it would be as benificial as one might think.

 

[Papabear]

The compressor will most likely be a freestanding unit under the fenderwell in the back... but I will look into the 200amp... The idea of relying on one alternator still concerns me a bit... I don't wanna be stuck in BFE with a dead alternator that is tough to find either...

thanks for the replies guys... I appreciate the help.

So carry a spare alternator order 2 at the same time and carry one like a spare tire. I know that i carry quite the spare part kit whereas short of a "major meltdown" I have it with me or the ingenuity to get my truck to where I can deal with it. I also carry a weeks worth of survival gear for 4 people ie. tent, food, stove, axe, sleeping bags good to -40C, fishing gear also every family member has 3 changes of clothes including footwear (kids clothes are changed out every 6mos to make sure they fit). everything is packed in watertigh containers.
(MAYBE I'M A LITTLE OVER PREPARED) But where I live depending on direction of travel it can be up to 4-10hrs before civilization and I have driven for 3 hrs. on the hwy before seeing another vehicle. And I have to carry so much food because canadians aren't allowed to carry firearms unless we have a specific purpose for them we may not have them just for emergencies.

 

[dakotajeep]

So carry a spare alternator order 2 at the same time and carry one like a spare tire. I know that i carry quite the spare part kit whereas short of a "major meltdown" I have it with me or the ingenuity to get my truck to where I can deal with it. I also carry a weeks worth of survival gear for 4 people ie. tent, food, stove, axe, sleeping bags good to -40C, fishing gear also every family member has 3 changes of clothes including footwear (kids clothes are changed out every 6mos to make sure they fit). everything is packed in watertigh containers.
(MAYBE I'M A LITTLE OVER PREPARED) But where I live depending on direction of travel it can be up to 4-10hrs before civilization and I have driven for 3 hrs. on the hwy before seeing another vehicle. And I have to carry so much food because canadians aren't allowed to carry firearms unless we have a specific purpose for them we may not have them just for emergencies.

A man after my own heart....I carried a multitude of stuff when I traversed the northland.....now I just carry a cell phone and a coat. People are never far away in Alabama.....unfortunately....

 

[Dsl_Dog_Treat]

I'm for 1 alternator and carrying a spare.
The nice thing with these motors is the fact that little voltage is required to actually run them.

 

[motorbreath53]

spares are never a bad idea....

but, if i'm carrying the alternator anyway, it might as well be earning its ride.... right?

I didn't figure i'd be finding a direct bolt-in solution....

anyway, if I end up building the brackets an' all, i'll be sure to post pics...

Thanks guys.

 

[icanfixall]

Dual alternaters are a direct boltin option but only found in an ambulance type vehicle. You can find them but sometimes they are harder to find in wrecking yards. I have seen some on Evilbay too...

 

[jperecko]

I had considered this as well... My vehicle, like yours, has to be somewhat dependable in the middle of nowhere. I basically concluded that the hood space would be better used for a spare AC compressor for onboard air. If my alternator goes, I should be able to run on the batteries for at least a few starts... seeing as I will have 2 sets. I might also carry a spare alternator along with some other spares.

By all means post up pics if you get something setup. I would be very interested in seeing results.

 

[subway]

i would like to see how this works to, another problem you might run in to is belt length. the serp. belt on a 7.3 idi is the longest on carried at my local parts store. i managed to get a longer on to play with adding an accessory but it was a 8 rib one for a newer hemi. i cut two of the ribs off to work but it is not an optimal solution.

 

[snoredog]

Motobreath I was thinking the same thing as you. I have a thing for auxillary lighting as you can see in my avatar. They came in handy after a concert on the front lawn of my college campus one night about 1 AM. Me and a bunch of guys from the baptist student union were breaking all the equipment to help the guys get back home that day. First thing to come down was the stage lighting, and there are no lights anywhere on the front lawn. The handful of flashlights between 40 of us didn't too much good. So finally I got the campus police to let me pull the truck up on the grass so we could shed some light on the situation. So overjoyed to finally use them for something constructive I flipped on lows, highs, and the roughly 720 watts of lights on the rollbar and went back to work. After a few minutes the lights started getting dim so i checked just in time to see the voltmeter hit the red zone. Finally balanced it so only the rollbar lights were on and it idled for almost 2 hours with no problem. So my question is this. Considering most of the time those lights are burning, the engine is around idle. Would a single high output alt handle all this? Call me nuts but I have 4 more spotlights in the garage that will go on whenever i get the bumper finished. Then a few floods. Then the 2500 watt inverter that may power a tv and xbox when we get bored on the long camping trips. I know a generator would be the best option but i cant really afford to buy and carry one around all the time. The truck when I am finished would be set up a lot like motobreath was talking about, only with a much heavier electrical capacity. Any chance of having a clutch setup like is on an ac compressor? Or is there any downside to running both alts all the time? If it helps any I was going to have 4 of the heavy diesel batteries wired up along with a 1 or 2 farad capacitor to absorb the shock of all the lights coming on at once. Let me know what you smarter guys think.

 

[Agnem]

A dual alternator setup will add a lot of complexity and difficulty in troubleshooting. I'd definitely agree that a single with a spare is a better option. The electrical gear needed to isolate one alternator from the other would be expensive as well.

 

[snoredog]

so you have to isolate each alternator from each other? I dont really know how all the charging and regulator stuff works so if anyone wants to explain or knows a link on here it would be great. I thought dual 12 volt alts running together would just double the amperage. But I am only 20 and have no training except what my dad taught me and what I learned from tearing stuff up myself.