dual alt wiring

anybody got wiring diagrams on there dual alt setup........................or pics

redneckstylin said:

anybody got wiring diagrams on there dual alt setup........................or pics

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dual alts!!!! what the f FOR?????

One heck of a CB set up? :dunno: Why not 4? :cheers:

i didnt ask for input .......................:dunno:


i asked for wiring diagrams and pics i know theres a few people o the board with this setup mine is mounted in place belts on no issues ready to do some wiring now............


but if your wondering whyyyyyyyyyyyyyyyyyyyyyy

simple operating a winch,headlights,stereo,6 6inch spotlites,cb,beer cooler,inverter,oba,and useing your cig lighter to spark a cigar,in a big ass water hole is not freindly on just 1 alt so i mounted another above it i like to be different :gee:

Fairly common on vehicles expecting high electrical loads - like late-model Ford ambulances (I think the primary is good for 160A, and the secondary for 140A or so...)

It's easy enough to do - just get a "one-wire" Delco CS-130 or CS-144 (whichever fits) for the second unit. The regulator pickup will be internal to the alternator - you literally have to hook up only one wire to make the thing work. Make sure you get at least 145* of belt wrap around the pully.

5-90 said:

Fairly common on vehicles expecting high electrical loads - like late-model Ford ambulances (I think the primary is good for 160A, and the secondary for 140A or so...)

It's easy enough to do - just get a "one-wire" Delco CS-130 or CS-144 (whichever fits) for the second unit. The regulator pickup will be internal to the alternator - you literally have to hook up only one wire to make the thing work. Make sure you get at least 145* of belt wrap around the pully.

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ok thank you for that info never new they existed ..........now could i just do the 2 wire application and have the battery wire and instead of ignition wire wire it to toggle? would that not work?

ill grab some pics of how my belt is routed with both alts in

my xj is a 88 so i do beleive it has the gm style alt on it looks pretty similar

1 more question 5-90 ...........how would you suggest running the 1 wire alt


a. dual batterys and dual alts with toggle switch so im not constantly chargeing that battery

b. single bat 2 alts where i have lots of charging happening on that 1 battery

c. go to beer store think through more

Please post pics!! Extremely interested in this!! But... i must ask.. why not a bigger alt? Is this cheaper? I have seen alts that can supply double the current of stock... Or dual battery set up... i guess that is best if you are running your electric loads less frequent?

Im running about 1200W peak stereo, air compressor, and anticipating 4 100w roof lights, 2 100W bumper lights... and of coarse the headlights and driving lights... So, im in need of some power too.

redneckstylin said:

ok thank you for that info never new they existed ..........now could i just do the 2 wire application and have the battery wire and instead of ignition wire wire it to toggle? would that not work?

ill grab some pics of how my belt is routed with both alts in

my xj is a 88 so i do beleive it has the gm style alt on it looks pretty similar

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Search a few RV forums, they will have a lot of info on dual alternator/dual battery setups.

As you already have the alternators mounted, I will not try and talk you out of doing it.

(If it was me, I would have mounted a single CS-144 200 amp.)

redneckstylin said:

1 more question 5-90 ...........how would you suggest running the 1 wire alt


a. dual batterys and dual alts with toggle switch so im not constantly chargeing that battery

b. single bat 2 alts where i have lots of charging happening on that 1 battery

c. go to beer store think through more

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Since it sounds like you're planning on a lot of electrical accessories, here's my spin:

1) Install a secondary deep cycle battery on an isolator. This will allow you to use the acessories with the vehicle turned OFF, without draining down your starting battery.

2) Wire the second alternator's output lead directly to the secondary battery - creating, in effect, a secondary electrical system (they may share a common ground without difficulty.)

3) Monitor operation and performance for the first fortnight or so to make sure it's behaving as it ought to (it should.)

When I was referring to a Delco alternator, I was referring to the secondary alternator - getting a Delco CS or SI series set up as a "one-wire" unit is quite simple - just find a local shop that will do the job for you (I believe it is merely a regulator swap, but I've never asked. It's plenty common for stationary engines/equipment, industrial equipment, kitbuilders, conversions, and the like - and Delco is probably the most common brand for the job.) Specify that you want a one-wire hookup, if the guy doesn't know what you're talking about it's time to find someone else. RENIX uses the Delco CS130 as OEM (in 60A, 80A, or 100A ratings,) but what you use for a secondary alternator is usually less important than replacing the primary - if you want to use a 200A CS144 and it fits, go ahead! Convert it to one-wire to simplify matters for yourself, and just make it all line up. You could do the smae thing with 1991-up rigs, and they all use externally-regulated Nippondensos for primary electrical generation.

5-90 is correct. You could have an AC delco alternator with an internal regulator that uses 1 wire, the out-put wire.
Since you are going to the trouble of fitting 2 alternators, I would advise you to have the 2nd alternator completely independant of the starting battery ie; its own battery/s, isolator or disconnect switch, monitor guages and most importantly connected to its own load. I am accustom to this setup having come form the marine industry and a certified Mercury/Mercruiser mechanic while spending plenty of time fixing single engine yachts with multiple banks of multiple batteries.
Grab a scratch pad and pencil along with your favourite beer while you brain storm over it.

ok carry on with a little more detail please with the deep cycle and isolator running stuff of secondary while engine not running

try this link : http://tinyurl.com/yarrwo5

Best answer do a google search for battery isolator and go with a good brand. They will allow you to connect both alts to one isolator and then subsequently to two batteries (which would be a good idea). Then power half of the electronics from one and the other half from the other, like stereo and lights and stuff to use when jeeps off from one and the jeep and winch from the other.

redneckstylin said:

anybody got wiring diagrams on there dual alt setup........................or pics

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i run a 2x4 davemade linear with 1 136 amp nipindenso with two batts the amp draw is about 100 amps const. works i said why for cause there isnt much room in a xj for dual alts. also you might check out mean green alts they do one thats 200 amps i belive for the jeeps. o and as for a battery iso. i would wire a contant duty soliniod way cheaper and less complicated

On the 1988 year XJ, I believe the alternator voltage is not controlled by the PCM. If that is true, then you would not have to worry about the PCM going into tantrums when two alternators are charging the same battery or battery bank. However, I would not under any circumstance connect two alternators to the same battery. The difference in voltage however miniscule could cause one or both alternators to malfunction. Remember, wether or not the regulator is internal to the alternator or external, the voltage is regulated by what the alternator think the battery voltage is and adjust the output accordingly based on the regulator. If one alternator is regulated to 13.5 volt and the other to 13.8 volt, how would either of the two interpret what it is seeing?

I have never seen two alternators hooked to the same battery. To me, it is just good practice not to do that. I would stay away from electronic isolators, solonoids and everything else that would connect both batteries together. Maybe a manual connect switch that you use only when one alternator is not working or if the starting battery is low and using it only long enough to get the engine going. I think that the only thing both batteries and the corresponding alternator should share is a common ground.

techno1154 said:

On the 1988 year XJ, I believe the alternator voltage is not controlled by the PCM. If that is true, then you would not have to worry about the PCM going into tantrums when two alternators are charging the same battery or battery bank.

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Correct - 1984-1990 XJ used either the Delco 12SI or CS130 (except for the Diesel, that was a Paris-Rhone,) with an internal regulator. Ergo, the ECU simply don't care - it's not involved. As long as the input voltage doesn't go out of range (+9-15VDC, I believe,) it's fine.

techno1154 said:

However, I would not under any circumstance connect two alternators to the same battery. The difference in voltage however miniscule could cause one or both alternators to malfunction. Remember, wether or not the regulator is internal to the alternator or external, the voltage is regulated by what the alternator think the battery voltage is and adjust the output accordingly based on the regulator. If one alternator is regulated to 13.5 volt and the other to 13.8 volt, how would either of the two interpret what it is seeing?

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Which is why the second alternator should be wired to a secondary battery - they may share a common ground, but that's about it. Did I forget to mention that? I'll have to check.

techno1154 said:

I have never seen two alternators hooked to the same battery. To me, it is just good practice not to do that.

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Good practise and contributory to sysstem longevity. I believe the Ford ambulance setups are done so that the primary runs the engine, lights, and other vehicle-related electronics; while the secondary runs all of the electronics relative to keeping the patient in workin' order until a surgeon can get to him.

techno1154 said:

I would stay away from electronic isolators, solonoids and everything else that would connect both batteries together. Maybe a manual connect switch that you use only when one alternator is not working or if the starting battery is low and using it only long enough to get the engine going. I think that the only thing both batteries and the corresponding alternator should share is a common ground.

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An "electronic" isolator is, essentially, a high-current diode pack - and is the ideal choice for a setup like this. If you were charging off of a single alternator, I'd say you could use anything that would separate the batteries with the vehicle OFF. However, if you're going to run doubled alternators and not run adjustable regulators to tune them as close to each other as possible, isolating the "hot" side of the circuits just makes good senses - and the diode pack will keep them isolated at all times. This is the better solution.

redneckstylin said:

ok carry on with a little more detail please with the deep cycle and isolator running stuff of secondary while engine not running

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Here is a wiring diagram for dual batteries. The only difference for you is that you would not close the solenoid with the ignition switch, so scratch that part. The batteries would stay isolated unless winching for instance. The second alternator would be wired to the second battery.

went out bought a 1 wire alt next is a marine battery i was thinking and ill have pics in a week or 2 here