Dual Alternator install

[MichaelOverfield]

Ok, so here is my attempt at a summary, first part, recap on parts needed:
(to be updated and corrected as needed)

PARTS LIST FOR DUAL ALTERNATOR INSTALL:
Alternator Bracket (XF7): MOPAR #: 04627793AA $ 59.72 (Moparpartsoverstock.com)
Alternator bolts (M10X1.5X105mm) (qty 2): MOPAR#: #: 06506337AA $3.20 (Moparpartsoverstock.com)
Bracket upper bolts (to engine block) (qty 3): $3 M-10 X 1.5 X 25 or 30 mm long (Lowes)
M-10 Washers (Qty 3): $0.50 (Lowes)
Bracket lower bolts (qty 2) (to fuel pump): M-8 X 1.25 X 40 to 50 mm long: $2 (Lowes)
M-8 Washers (Qty 2) $0.50 (Lowes)
Left Fan shroud Bracket: MOPAR# 68160116AA $64.70 (Moparpartsoverstock.com)
Mounting bolts (qty 2): M-8 X 1.25 X 50 mm long: $2 (Lowes)
M-8 Washers (Bag, QTY 20, use as needed to obtain correct fan shroud bracket fit): $2 (Lowes)
M-8 Nut, M-8 washer (or re-use existing, I needed one as I found one missing): $1.50 (Lowes)
Serpentine Belt MOPAR#: 04627589AA Gates #: K081298HD $ 28.79 (closeout deal) (Rock Auto)
Alternator, MOPAR #: 56029707AB, 56029707AA (About $400 new) Remy #: 11015 $129.79 + $ 50 Core ($179.79) (Rock Auto)
Bracket, Radiator hose: MOPAR# 68195735AA $6.58 (Moparpartsoverstock.com)

Electrical:

Alternator connector (2 pin): AIRTEX/WELLS# 1P1830 $12.50 (Rock Auto)
Alternator/Battery/Fusible link wire: OEM (68145075AB) $56 for*
*( I made my own: In-line 250Amp ANL fuse holder: $13.85 or you can use a 250A manual reset circuit breaker ($10) (Amazon.com) )
Dorman 85684 Conduct Tite GM Alternator Wire Boot: $6.13 (Amazon.com)
ABN Marine Battery Cable & Tinned Lug 1’ Foot in Red, 3/8" Inch Stud, 4-Gauge: $7.99 (Amazon.com)



Driver card:
VN7004CLH evaluation board high side driver board ($4.47 ea only one needed) (digikey.com)
Aluminum DIY project box $ 10 (Amazon.com)
15 Amp Diodes (pack of 20, only need 3) $7 (Amazon.com)

Wiring accessories:
Striveday Flexible Silicone Hook Up Wire 18awg $19 (Amazon.com)
Waterproof Cable Glands (pack of 30, need only ONE) $10 (Amazon.com)
Various Wire loom/protector 1/4", 3/8”, 1/2” $25 (Amazon.com)
Connectors Waterproof (3 pair) E-Ting 10 kit 2 pin Way waterproof elec plug. $12 (Amazon.com)

Optional:
4PDT on/on Switch $8 (Amazon.com)
DPDT on/on Switch $7 (Amazon.com)
Qty 2- 400A Mini Current/Volt meter with Hall Effect Sensor Transformer $48 ($24 ea) (Amazon.com)

Tools:

Serpentine Belt tool Kit: Gearwrench 3680 $41 (Amazon.com)
Serpentine Belt grabber tool: ATD Tools 8604 $22 (Amazon.com)

 

[MichaelOverfield]

Steps to install:
1. Connect the High Side driver board in the project box, be sure to wire the diode in the output as shown, and test this circuit for proper operation. I used an additional diode to get the voltage to match (that second diode providing a small voltage drop on the output.

2. Install the alternator bracket, removal of the EGR crossover pipe makes this much easier. Bolts to the engine (3 bolts holes already tapped on engine) and the lower part bolts to the top of the HPFP housing. You’ll have to move one bolt used to hold a wire harness, but there is plenty of room to route it around the new bracket.

3. Remove the 3rd Gen upper LEFT side fan shroud bracket, this has one bolt on the fan shroud, and 2 on above the CP3 pump.

4. Install the 4th Gen upper LEFT side fan shroud bracket. You’ll need slightly longer bolts than used on the 4th Gen, and as small stack of washers to space out about ½” to get the bracket to properly support the fan shroud, it becomes pretty obvious when you fit it up.
5. Install the second alternator with the 2 alternator bolts.

6. Remove the Air Cleaner for access to the right (1st) alternator and connectors, and you’ll need it out to do the serpentine belt, and cover the intake to keep things OUT of the intake.


7. Use the new alternator plug to connect from the new 2nd alternator to the area near the existing alternator (I should add, the “existing alternator if not the 220A.. make it the 220A! That is a bolt and plug on replacement). I used additional waterproof connectors near the existing alternator to connect the entire set up, and to the optional switch network. In the event of some wiring problem, I can move a few plugs and cut out any of the new wiring and go back direct from the ECU to the original alternator, or the new alternator. I made the ECU plug a male connector, the alternators Female, and the connector to the inside truck/switches the opposite. There will be 3 connector pairs near the right side alternator to do this. If you don’t want the switches, you’ll still need the ECU field output to route to the High side driver, and the output of that driver to feed the second alternator, that will be 2 wires into the cab (you do NOT want the driver card under the hood). With my switches I had 6 wires to run.

8. Connect the new alternator output using a fusable link (OEM style) or 250A fuse/breaker to the battery.


9. Remove the old serpentine Belt and install the new longer belt. Make note on routing, this thing I’m convinced is a mind bender puzzle. Draw it out, you’ll regret it if you don’t! If you can have 1 or 2 helpers with the belt, do so. I learned a few tricks, use the serpentine belt tool, and if you need to ratchet it, use a socket on the side of the tensioner to hold the spring tension as needed while adjusting the tool. Also if you prop the tool with a block of wood against the right inner fender, you can hold the tensioner while struggling with the belt. You’ll be able to get BOTH hands all scraped up for equality. Even with that, it was still seemingly impossible, and at about midnight I decided to do something radical (no, the various forms of lumber and assorted hammers was not yet radical), I pivoted the right side alternator by removal of the top bolt, loosening the lower bolt. Doing this I was able to get the belt on, finally.. But then I had to use a hydraulic ram to gently pivot the alternator back and reinstall the bolt. I will do it this way again if ever needed.. it actually worked very well.

10. An earlier post detailed the electrical connection for the new alternator, to summarize, the driver board needs it’s own power and ground. I just used the ignition side accessory plug power for this. Then the board has an input (from ECU/Alt 1 field) and an output, to field on Alternator 2).

11. Re-install the air filter housing, and reconnect the MAF/TEMP/Pressure sensors.

 

[Bob4x4]

How much are you going to run off the charging system to warrant all your time invested?

 

[MichaelOverfield]

How much are you going to run off the charging system to warrant all your time invested?

Hard to say, If I add the very large inverter and use it as a back up power source for the house, well pump, work site, RV.... probably will get lots of use. I won't have to drag out a portable generator and lug that around, saving cargo space. I have an easy to move tiny portable for small stuff and charging the battery, camping etc. The truck will be for the big stuff. Yes, it was a big job, but for someone else having the figuring out done makes this a much easier job for them than it was for me, which is why I tried to share it for others.

 

[subsea]

Excellent work!

What are you thinking about the installation location of a huge inverter? I have a crew cab, and have been running out of ideas to mount it in an area that might be cool in the summer (inside the cab). Don't believe they will fit under the rear seats. I thought about buying a cheesy inverter and hooking it up while in transit, and whipping out the big boy from the tool box when on location and just leave it on the floorboard or similar.

Let us know what you find when you get some real load hooked up to your system.

 

[MichaelOverfield]

Excellent work!

What are you thinking about the installation location of a huge inverter? I have a crew cab, and have been running out of ideas to mount it in an area that might be cool in the summer (inside the cab). Don't believe they will fit under the rear seats. I thought about buying a cheesy inverter and hooking it up while in transit, and whipping out the big boy from the tool box when on location and just leave it on the floorboard or similar.

Let us know what you find when you get some real load hooked up to your system.

If I didn't already have an aux fuel tank in the front of the bed, I'd be looking at a tool box for the inverter install. Since that won't work, I have some conceptual ideas for a under the bed options for an inverter and perhaps a couple of additional batteries. When I start that, I'll also begin a new thread.. it promises to be a whole new challenge!

 

[MichaelOverfield]

I wrote to thank my expert electrical engineer friend, David Swanson, and he pointed out that I need not be concerned with a small difference in the field voltages going to the 2 alternators. It gets a bit technical, but the summary is this: the resistance, and thus current through each alternator field will self equalize, since the higher voltage, thus current alternator will heat up more than the other, and that higher temperature will increase field coil resistance, which lowers current, and thus balances the output! Amazing, and helpful to know for this this project. So the additional diode on my output for the driver board was not needed, though I don't expect it will be a problem either. Just something to consider for the next person wanting to take on this project.

 

[MichaelOverfield]

UPDATE: the system still works; there is however one annoying glitch I have yet to work out. When a really large load shuts off, in this case it’s the grid heaters, it starts a cycling of system voltage that does not stop, it’s too fast to see on a meter, but it is seen by pulsing lights, now if I wanted to look like an ambulance, perhaps it would serve that purpose. I can see the issue because I monitor the field voltages, the primary alternator voltage goes down, but there is a lag for the second alternator to do same, enough lag that the primary overshoots down, then the second follows, but now voltage is too low, to primary goes back up, too far, then secondary follows, and the cycle repeats. It can be ended by going to single mode on either alternator (or a large load, like grid heaters back on), so it’s just an annoyance. My electrical engineer advisor has suggested a delay circuit to cut out the secondary when there is a voltage spike, I’m evaluating that option, or some option to bring up the secondary only when the load is high enough to stay stable, then drop off line when the load is secured. One of these options will likely be used, in the meantime, the mode selector switch is used to deal with the issue as needed.

 

[subsea]

UPDATE: the system still works; there is however one annoying glitch I have yet to work out. When a really large load shuts off, in this case it’s the grid heaters, it starts a cycling of system voltage that does not stop, it’s too fast to see on a meter, but it is seen by pulsing lights, now if I wanted to look like an ambulance, perhaps it would serve that purpose. I can see the issue because I monitor the field voltages, the primary alternator voltage goes down, but there is a lag for the second alternator to do same, enough lag that the primary overshoots down, then the second follows, but now voltage is too low, to primary goes back up, too far, then secondary follows, and the cycle repeats. It can be ended by going to single mode on either alternator (or a large load, like grid heaters back on), so it’s just an annoyance. My electrical engineer advisor has suggested a delay circuit to cut out the secondary when there is a voltage spike, I’m evaluating that option, or some option to bring up the secondary only when the load is high enough to stay stable, then drop off line when the load is secured. One of these options will likely be used, in the meantime, the mode selector switch is used to deal with the issue as needed.

Can you just install another evaluation board on the original alternator circuit, that way both alternators are playing on the same field(see what I did there?)

Can you hazard a guess as to what frequency it is oscillating voltage? Just curious.

 

[MichaelOverfield]

Can you just install another evaluation board on the original alternator circuit, that way both alternators are playing on the same field(see what I did there?)

Can you hazard a guess as to what frequency it is oscillating voltage? Just curious.

That is an interesting idea, and since I do actually have 2 boards installed already, it could be re-wired to do just that, in fact I could just tie both to the same board output.. the concern might be if the computer has any alternator diagnostics that it would sense a lack of field current on that ECM output, because with all the output from the driver boards, the ECU output now becomes a voltage signal with no load.. but that could be fixed with a suitable resistor if needed.. but interesting idea. I'll run it by the expert, but initially I'm not sure it addresses the root cause, which is the much larger capacity being mismatched to the regulator gain from the ECU, however from what I can tell the lag time between the direct ECU and the driver board output appears to be at least part of the issue.


For the frequency of the voltage fluctuations, I'd say 2-3 cycles per second or so, I haven't measured it, it's just a guess from observation. To see it I turn on one of the interior lights.

Initially I thought the break-in of the slip rings on the new second alternator might be the cause, so I gave it some run time in single to get the brushes seated, (it would fluctuate a bit in single mode on that alternator, but it no longer does that). Now I'm positive it's due to the lag time/ECU gain not being able to adjust to the drop off in large load, such that it starts a repeating cycle.

 

[subsea]

Also, what about installing a ~ 1 Farad capacitor between the battery and the TIPM? I know it's just a band aid for this issue, but power spikes/oscillation might actually be inherent to the design of this dual alternator setups with abrupt load changes. It would be nice to keep smooth voltage through all of the computers.

 

[MichaelOverfield]

Also, what about installing a ~ 1 Farad capacitor between the battery and the TIPM? I know it's just a band aid for this issue, but power spikes/oscillation might actually be inherent to the design of this dual alternator setups with abrupt load changes. It would be nice to keep smooth voltage through all of the computers.

I'm sure it would not hurt anything, but my electrical expert noted the capacitace of the dual batteries if far above any capacitor I could add.. so unlikely to do much, and I definitely don't want unstable power to the computers, for sure. Now, I might be adding another battery, or two.. and that would possibly change things. It's not in the immediate future, but if/when I get to the large inverter, part of that would be batteries in close proximity to deliver the surge current for such a large inverter.. and with the extra batteries to charge it would add considerable more capacitance to the system, and might dampen things out with that change alone.. but I'm leaning toward the delayed on circuit, and the off for low loads for the second alternator.. though the drive both, with the boards as you suggested might work, I could perhaps try it to see if I get an error from the ECU not sensing current on that circuit, I don't see how it could be hurt by a lack of load.. but I'm going to ask for an opinion from the expert to be sure.

 

[brods]

Just curious if you've researched what the factory did for dual alts? Such as: what, if any, extra electrical protections are in place, how they control the fields, do they stage the alts or are they always operating together, etc?

 

[MichaelOverfield]

brods, yes, I did look into the 4th Gen strategy. I did not get the specifics, other than they were all pre-wired, but not programmed to run both, unless that option was installed at the factory. Some actually wanted to delete the second alternator, and that too required a reprogram of the ECU to remove the second alternator. Others who bought the brackets, belt and alternator, still needed a dealer visit to program the ECU to run the second alternator, so it does control them independently, in some fashion. I did find some more specific information on how Ford controlled there dual alternators, and that was interesting because it would not run both unless needed, and would alternate which one was online at some programmed interval. As far as 3rd Gen goes, no such dual alternator option from the factory was available, so it became clear to me, that if I added the additional load to drive a second alternator field to the existing ECU circuit, I could be asking for damage to the ECU, and hence the search to find a way to independently drive the second alternator, while still using the ECU's circuit to control the overall voltage of the system. I was able to achieve this with help from the expert, and it works extremely well when it is pulling a heavy load, the only problem comes when the load secures, and it can't seem to dampen out all the transient voltage as it hunts to become stable at the much lower load, and never gets there, this when each alternator is not really working hard at all (field voltage is a mere 1.5-3 volts, where full field would be 12 or more). When field voltage is over about 6 volts, the system dampens out and fluctuations stop, generally with existing equipment, that is ONLY when the Grid heater comes on, I can turn everything else in the truck on, and still not go above about 4 volts when both alternators are online.

 

[subsea]

I could perhaps try it to see if I get an error from the ECU not sensing current on that circuit, I don't see how it could be hurt by a lack of load.. but I'm going to ask for an opinion from the expert to be sure.

Should be a simple test of just unplugging the main alt, with the blessing of your expert. Did you ever toggle the main alternator off with the "Single Alt Select" switch on the left side of your panel? That should be a sign that the computer would only throw a code on low voltage. I scanned the list of normal OBDII codes, and couldn't find one that specifically called out an alternator or generator.

 

[MichaelOverfield]

Should be a simple test of just unplugging the main alt, with the blessing of your expert. Did you ever toggle the main alternator off with the "Single Alt Select" switch on the left side of your panel? That should be a sign that the computer would only throw a code on low voltage. I scanned the list of normal OBDII codes, and couldn't find one that specifically called out an alternator or generator.

The way I have it wired, it would not be difficult to test, however I'm about 100% sure the ECU will throw a code of some kind if the field is disconnected (or unloaded where it only drives the board, which in turn drives the field), I did find this:
http://www.allpar.com/fix/codes/faults/code-41.html

It would not fall under OBDII since it is not emissions related in any way.

The Dual mode switch is On/On, there is no middle off, so only a very short disconnect between switching modes. The Single Mode selector switch is also a On/On, so that means there is a very short no connect when switching, as with most all error codes, there is a system time delay to prevent spurious codes, so it would need a longer period of time disconnected before the computer would throw a code. I could try it by just disconnecting the #1 alternator to see what happens. I do recall reading somewhere about a voltage regulator kit that could be used when the ECU driver had a problem, but rest of the ECU was still working, and in that kit I recall it did mention there would be an error code of some kind since the ECU had no control of the voltage on the system.

 

[subsea]

Apparently I didn't look close enough. You might be right....but I'll wager it doesn't throw a code if the second alternator is online (I like to live dangerously)

P0620 Generator Control Circuit Malfunction
P0622 Generator Field F Control Circuit Malfunction
P0625 Generator Field Terminal Circuit Low
P0626 Generator Field Terminal Circuit High

There are a few other P06XX codes that have nothing to do with emissions.

 

[MichaelOverfield]

Apparently I didn't look close enough. You might be right....but I'll wager it doesn't throw a code if the second alternator is online (I like to live dangerously)

P0620 Generator Control Circuit Malfunction
P0622 Generator Field F Control Circuit Malfunction
P0625 Generator Field Terminal Circuit Low
P0626 Generator Field Terminal Circuit High

There are a few other P06XX codes that have nothing to do with emissions.

Interesting. While OBDII is required per emmisions, many OEMs added additional items that are also accessible. Of course one might say alternator is emmisions related, since all the electronics demand power to operate. Thanks for finding that.

 

[subsea]

Did you find anything out?

 

[MichaelOverfield]

Did you find anything out?

I haven't had any additional input from David Swanson. He proposed a circuit that would cut out the second alternator with a voltage spike, but I'm not so sure that will solve the issue. I'm leaning towards a bi- state relay circuit off the primary alternator field circuit. At 11 volts, turns on second alternator.. then if voltage goes below 5 volts.. turns it off. This basically replicates what I do now manually by switch.. so I'm pretty sure it will work. I've added some of the components to my Amazon wish list.. likely will take it on when the weather improves.