Has anyone tried hooking a battery isolator to the stock generator of a 69 472 to charge a second battery for lighting and stereo while sitting? Thinking about doing this in the hearse. Can I locate the battery "in" the car under the storage space in the back of the hearse or do I have to worry about ventilation of battery fumes? Thanks.

just get a drycell battery so u dont have fumes to worry about

Being that this is a generator/voltage regulator set up will that make a difference? Will the voltage regulator work properply?

The old mechanical regulator? Yech. Might I suggest considering a newer 10 or 12SI alt? MUCH more efficient, easier to replace/find parts for, and you get to eliminate a bunch of wires from under the hood, if you opt to do so.

Yeah everythin there is still stock. Generator with the seperate regulator mounter to the passenger side wheel well. Dave sounds interesting can you elaborate on wire reduction and where to find this alt.? I was thinking even a dual output alt. and just run one output to each battery. Any ideas on where to find one. Either that or a battery isolator. Thanks.

Just about anywhere has the alt in stock. A 10SI 63 amp alternator that would work well on your car has AC-Delco P/N: 321-43 Or, if you go the parts counter route, get one for a '77 Pontiac Grand Prix, 350 VIN R engine, with Air COnditioning, and Heated back light (rear defogger). The alt has three wires, one to the battery, one runs to the old mechanical regulator harness (controls the idiot light) and one is the remote sensing wire. Neat feature, but for simplicity, you can connect it right to the batt lug. The good part about these alternators is availability. almost every aftermarket "street rod" alternator is based off the same design. That means, if so inclined, one can buy one in a pretty chrome case. :)

As far as the isolator, if I understand correctly, there nothing more than a big diode? Not sure what an isolator would run, but it should be pretty easy to come up with a way to disconnect one of the batteries automatically when the ignition is off. (wonder what the duty cycle of those ford starter solenoids is... could get one of those for next to nothing...)

So then get rid of the regulator all together? Just still plug in the harness for the idiot light? I have not looked at it yet. Is there a connector I'll need in order to plug in the old harness?

Sasquatch, Dave Smed helped me out with a similar issue on my '68. Here's the link with pictures. 68 Cad Wiring Problems (http://www.cadillacforums.com/forums/showthread.php?t=38285&highlight=Colt)

Take a look @ M.A.D Electrical (http://www.madelectrical.com/electricaltech/onewire-threewire.shtml)...there are some awesome pages on old GM alternators (with wiring diagrams). The site also includes a really thorough discussion on how the old voltage regulators work, and the best placement for that voltage sense wire.

It won't help much with the 2 battery question, but it will make the existing system a lot more easy to understand! :)

All you need is one wire out of the regulator harness with the new alternator. if you just want to keep the stock plug, you can use a plain male quick connect, like the kind used on the BATT terminal on a GM HEI.

Excellent link! MAD electrical is a great place for information.

A 10SI 63 amp alternator that would work well on your car has AC-Delco P/N: 321-43 Or, if you go the parts counter route, get one for a '77 Pontiac Grand Prix, 350 VIN R engine, with Air COnditioning, and Heated back light (rear defogger).

Dave, I'm going to go with the Alt. upgrade you suggested along with the MAD Electrical wiring kit. Will the alt. you suggested line up with the exsiting brackets on my 472? What parts distributor would carry the Delco P/N 321-43? Napa or Advanced? I would like to pick it up locally if possible to save on shipping. Also if I can't find it under that part number locally then ask for an alt. for the car you described above and it will work with my stock mounting brackets? Thanks alot and it's Saturday so I'm going to make some calls for availability but thought I would ask.

In reading about the Delco alt.'s on the MAD electrical sight they describe different "clock" locations for the wiring plug on the alt. I'll have to check and see which will work best for me. Also I discovered a battery isolator that will bolt to the Delco alt. I've included pictures and a description. Is the 1/4 inch post for mounting the isolator they describe the one in the picture of the alt. with the red plastic ring around it? Not sure I'm going with this particular isolator or not. Although it seems it would fit the bill nicely as long as there are no clearance issues. Here's the pics and info. Although in reading the info I do not see where it "isolates" the secondary battery during ignition off periods. I think it may be just for charging two batteries. Let me know what you guys think.


The DC-270 is designed to facilitate the installation of an additional battery on any boat or recreational vehicle to ensure that the engine will start after spending extended periods of time anchoring, trolling or camping.



The DC-270 will work on any 12 volt DC-negative ground electrical system with alternators of up to 70 Amps output. It is specifically not recommended for use with higher output alternators. The DC-270 will mount directly on the alternator output or 'battery' post on alternators with a 1/4" or smaller diameter post. This mounting system fits Delco, Mando, Motorola, Prestolite and many other marine and automotive alternators. In addition, the DC-270 may be flat mounted for applications where insufficient clearance is available, or for use on systems without alternators, such as outboard motors.

http://images5.theimagehosting.com/wagner3b.jpg (http://www.theimagehosting.com/)DC-270

http://images5.theimagehosting.com/delcor2.jpg (http://www.theimagehosting.com/)

Your Voltage regulator will not work properly with a battery isolator unless the regulator Voltage is taken from tha battery side of the isolator. The reason for this is the Voltage drop found in the diode in the isolator. It will be in the neighborhood of .6 to .7 Volts. This may already work in the Hearse with a generator but if you switch to an alternator with internal regulator then the regulator terminal should not be simply looped back from the B+ alternator post back to the plug. It should now go to the battery. Which battery? The one that starts the car.
You will be much better off with an alternator than the olde generator if you decide to change.

Thanks Ape, I figured the old gen/reg setup would not work with the isolator. I'm definetely going with a new alt. Just gotta figure out the best alt/iso setup for my needs. Take a look at the link provided earlier in this thread. it has alot of info on the benefits of upgrading from the old gen. setup to the 3 wire alt. Here's a diagram I found for wiring the iso with the alt. Is the post your referencing the one with the red ring around it in my picture?



http://images5.theimagehosting.com/Isolatorwiring1.jpg (http://www.theimagehosting.com/)

That article hits all the important points. The writer has an uphill battle to deal with in getting his point across concerning 1 wire alternators. "Joe downtown has had one on his Chevy for 78 years and it always worked for him". I can hear it now. There are legions of armchair, internet surfing, magazine reading, believe anything written in an advertisement, mis-information exchanging, never even changed a spark plug slugs out there to fight with. I wish him luck. Sometimes it's just better to let them flounder.
Back at the ranch, your schematic has no provision for taking the regulator sensing directly from the battery so it is incomplete. Your alternator will be .6 to .7 volts too low in output to fully charge the batt. Look again at the article. They call it "Remote Voltage Sensing". Look at trucking of heavy equipment outlets for isloators that can handle some heavy continuous current. A hint at current capability will be the size of heat sink mounted to the diode pair. A typical truck installation would be for a lift gate DC motor. The isolator gets tied to the alternator output and one isolator out goes to the truck's electricals, the other directly to the lift gate controls. The lift gate will now only work with the engine running so you cannot kill the batt.
Another good point in the article is the one made about alternator core sizing. There are tricks to increase the alternator's peak power that do little or nothing to increase continuous output. One way to increase an automotive alternator's output is to reconnect the 3 phase windings from a Y connection to a Delta. The Delta wound alternator will make more peak amperage at the expense of low output at low revs. When upgrading alternators, you want more continuous power. This will come with more cooling capability also. I like the Delco 21SI but have not tried adapting one to my Cadillac yet.

I planned on using the wireing kit that MAD electronics sells for the 3 wire alt. that provides a hook up for the remote sensing that you speak of. That way the alt. should maintain the proper output to the electrical system. Then the charging wire would go to the iso and be split by the iso to each battery. I'm assuming the third wire is ground?

B+, Voltage sense and ignition.

Ape man, would a possible low-buck option be an old ford style remote starter solenoid between the second battery and the first (wired in parallell) with the solenoid's "S" terminal wired to an ignition feed (hot in ON, but cold in ACC)?? If Sasquatch were to wire up the stereo equipment to the second battery, it would be isolated from the rest of the car as soon as the solenoid opened. Or do you think the duty cycle of the solenoid wouldn't cut it for some reason? Alternately, a drag racing cutoff switch would achieve the same thing, but lack the automation...


Oh, and yes, it will bolt right in. My alt. is clocked at 12.

So B+ would go to the iso. Voltage sense. Could this be picked up at the old regulator. The MAD article talks about tieing it in at the main junction as you would get a more accurate reading. Is there a wire for the old reg. that goes to this "main junction" where I could splice to? Ignition wire?

Those relays were used in plenty of other stuff besides Ford cars. I've seen them in several switching high Voltage automotive power supplies from '60's ham radio gear. Your idea seems pretty good. The one thing that could screw things up would be the coil current of the relay. They might not be rated continuously as you suspect. You could always get one and leave it hooked up as a test to see if it gets hot. They might have some sort of pull-in coil and hold-in coil winding similar to a starter. It might be an idea to see if the relay's coil can work with less current. The way to do this would be to series a string of diodes like (100 or better Volt at several Amps) in series with the ignition feed to the relay coil and find the right amount that will not pull the relay in at battery Voltage but WILL pull it in when the car's alternator has been running long enough to make say, 13.5 Volts. Each diode in series with the coil would drop the coil voltage by .7 volts (of course they have to be forward biased!). This would allow the main batt to get a reasonable charge before putting the alternator to work on the second batt. It would take a little work but would be a nice idiot proof way to go. Yes, this can be done with resistors but diodes would be much cleaner. With this setup, you simply hook all the audio stuff up to the 2nd batt, you can kill it dead and your ride will still start.

Just found this.

http://www.hartin.com/alt.htm

http://www.quietcanyon.com/delco_wiring.htm

In the second link it shows the bigger post marked BATTERY goes to the + side of the cars battery. At the top one marked BAT where does this go? Is this the remote sensing wire?

Here's a better one.
http://www.rockcrusher4x4.com/images/pdf/DelcoAlternatorWiring.PDF


Once again it looks like they are using the "sensing" wire to "excite" the alt. via the battery. Isn't it better to use this "sensing" wire at the main junction as suggested by mad so when there is any drain caused by running the cars normal electrical systems like lights, wipers, defogger,and so forth that the alt. would "sense" this and compensate output for this rather than just when the battery ran low?

The spade terminal marked "to Bat" is the sensing wire.

The other schematic calls it "F"

The post on the alternator rear would of course go to the isolator.

The interesting part is the ignition connection goes in series with the idiot lamp. This saves one set of contacts in the ignition circuit but will make your alternator look dead if the bulb opens! There were a number of model years that any suspected alternator had to be checked to see if it would start charging by jumping battery power through a test lamp to this terminal.

Slick idea with the diodes, I was thinking a smaller relay off the alternator side of the charging side myself. (like early chevy electric choke relays) And maybe a bypass switch to allow for jumpstarting the car with the other battery if the primary becomes discharged for some reason.


AS far as the voltage sensing part, the main junction for the car could probably be considered the starter battery lug, as all the fusible links are fed off of it. Since it has such a heavy gauge wire between that and the battery, and its not too legenthy of a run, the battery would suffice as a sensing point as Ape Man suggested. The other option would be to run a wire inside the car and go off the back of the fuse panel. While this would only be representative of part of the electrical system, it would probably provide a somewhat better output, depending on the loading of that particular branch. FWIW, I have 10ga from the back of the alternator directly to the battery, and the voltage sensing wire is landed at the battery. Works very well, but as with cars this age, the rest of the system could use some modernization to really use the extra power. (voltage at my headlights is hovering around 10 I think, engine running. Time for relays!) I only used one factory wire from the old setup. I disregarded the rest. The one was to the dash light.

http://www.madelectrical.com/electricaltech/onewire-threewire2.shtml

If you read here and on the next page he discusses that exact reason for running the sensing wire to the main junction. There is also pics of it. That way the alt. supplies the voltage necessary at THAT point when turning on headlights and so forth resulting in not as much voltage drop off. From his explanation by running the sensing wire to the battery you are not using the alt. to it's fullest potential but rather just as a "battery charger." I imagine getting to this "junction" is a pain in the neck and therefor a lot of people opt for the easier method of tieing it in to the battery. I've tried calling this fellow and no answer. I'm interested in using his wiring kit and going with his described setup. Just cant's get ahold of him. Although he does mention using relays for headlights in another section.

Ok took a picture of the back of the generator. The wire with the yellow connector goes to the plus side of the battery. I'm assuming this is for charging the battery. The other red wire coming from the post runs along the valve cover and then into the harness which is bundled together and I didn't want to unwrap everything just yet. My question is this. Is it possible to run the red wire with yellow connector to an iso then split at the iso to each battery? Therefor charging both batteries and then using the secondary battery for lights ect. during parked times with the igniton off? Or would this be to much drain on the generator and burn it up. Keep in mind this is a hearse with an electric table that turns and comes out of the car. I'll have to check my shop manual but perhaps these were equipped with a larger output gen? Thanks for all the input I'm learning alot. Here's the pic.


http://images5.theimagehosting.com/Generator.2.jpg (http://www.theimagehosting.com/)

Found this regarding generator output for the Commercial Chassis which my hearse is. My car has no AC. So I have a 55 ampere gen. even though I have no AC because all commercial chassis were equipped with those. There is an even bigger gen. that was an option for the commercial chassis that was a heavy duty 130 ampere. That is not what I have as the picture differs from what is in my car.


http://images5.theimagehosting.com/Regulator.jpg (http://www.theimagehosting.com/)

http://www.madelectrical.com/electricaltech/onewire-threewire2.shtml

If you read here and on the next page he discusses that exact reason for running the sensing wire to the main junction. There is also pics of it. That way the alt. supplies the voltage necessary at THAT point when turning on headlights and so forth resulting in not as much voltage drop off. From his explanation by running the sensing wire to the battery you are not using the alt. to it's fullest potential but rather just as a "battery charger." I imagine getting to this "junction" is a pain in the neck and therefor a lot of people opt for the easier method of tieing it in to the battery. I've tried calling this fellow and no answer. I'm interested in using his wiring kit and going with his described setup. Just cant's get ahold of him. Although he does mention using relays for headlights in another section.


Very good point, problem is, unlike chevies, the closest thing to a main junction that we have would be found at the back of the starter. Thats where the fusible links branch off for the headlights, fuse block, and other primary circuts. The starter has that huge wire from the battery directly to that lug, so using the battery as opposed to the main junction (in our case, the back of the starter) would provide almost no difference provided your main battery wire is in good shape.

Sounds good. So the 3 wire alt. hook up goes like this.

http://www.rockcrusher4x4.com/images/pdf/DelcoAlternatorWiring.PDF

Running through the idiot light provides the ignition source? What do you think about trying to use the gen. since it is a 55 ampere?

Picked up a battery iso off ebay. Gonna try to use it with 2 batteries and the exisiting charging system. I think it'll work just fine.

Liesure Components dual battery isolator model 2496

New, never installed.

isolator rated at 160 amp, for a max. 135 amp alternator.

includes installation instructions


http://i2.ebayimg.com/03/i/04/f7/d0/9c_1_b.JPG
http://pics.ebaystatic.com/aw/pics/s.gif

We used almost the exact same isloator in fleet service when some of the upper maneagment got a brainstorm
(always a dangerous situation as they were all headed for the out door). They had unfinished aluminum on the heatsink though. 2 doides in a sealed box is what you are looking at. Very reliable units. We punished them and they held up.
Maybe try it with the Voltage sense wiring left stock at first then hook it up to the main Bat. You should see a .7 Volt increase in charring, er uh charging Voltage.

I'm gonna run the main BAT wire to the iso then from the iso to each battery. Should work great and I won't have to worry about a dead battery come starting time after letting the car sit with lights and stereo going. I think I'm gonna hook up a fuse box to the second battery that way any accessory I run with second battery will be fused. Ape are you saying that the increase in voltage could cause some melt down or "charring" of exisiting wiring?

Nope. There will not be an increase. Initially it will decrease. You are shooting for the original charging Voltage before modification. You will see if you measure Voltage at the main battery with the engine running and no accessories running. It will drop .7 Volts with the isloator connected. This is the reason to move the Voltage sense wire over to the battery or it's load circuit if a drop is anticipated.

Well finally got around to hooking everything up. My question is this. In the directions it suggested hooking a circuit breaker between the auxillary battery and the isolator. The wire from the isolator goes to the top post on the circuit breaker marked BATTERY and the wire from the bottom post marked AUX goes to the second battery. I've included a pic. Is this correct? Normally when using these in conjunction with a battery to accessory I'm thinking you go from the battery to the top post and then from the bottom post to the accessory. In this case it should be hooked up like I have it. The top post is where current comes in and the bottom is where it goes out. Correct? Thanks for any help. Also hooked up a fuse box in the car for the second battery.

http://images5.theimagehosting.com/CircuitBreaker.jpg (http://www.theimagehosting.com)