Shop talk

[markopolo]

Originally Posted by WJones

Marko,

On 1996 to 2002 Express/Savana vans the voltage regulator in the alternator is controled by the Powertrain Control Module. The first question you have to answer is whether you can simply connect two alternators together. I would think the second alternator would need its own control circuit. If this has already been discussed ... just ignore me!

It gets interesting. The Haynes manual indicates that too.
I looked at another shop manual and it does not indicate that the PCM is part of the charging system on early model vans. However, by the 2002 model year the generator (alternator) is noted as being controlled by the PCM.

"Generator Turn On Signal" is listed in the PCM pin-out descriptions starting with the 2001 model year from what I've found.

[WJones]

Originally Posted by markopolo

It gets interesting. The Haynes manual indicates that too.

Not really a coincidence ... that's where I got it. However, they show 2 red wires and a grey wire. You have 4 wires and one of them is brown. I wonder if the PCM is just sensing the voltage and sending that voltage to the regulator in the alternator.

William

[markopolo]

The PCM controls the alternator output from what I've read. (on newer models) For example it will increase idle speed to spin the alternator faster to meet demand when necessary.

PCM Controlled:
Large Red - main cable to battery
Small Red to PCM "Generator Turn On Signal"
Small Grey to PCM "Generator Field Duty Cycle Signal"

For my van the wiring is the same for the primary alternator and the auxiliary alternator if installed.

Not PCM Controlled (CS144):
Large Red "Bat" - main cable to battery
P (Phase) terminal - not used
L (Indicator Lamp) terminal - Brown wire
I/F (Ignition) terminal - not used - (L terminal is used in place of)
S (Sense battery voltage) terminal - not used

My guess is that the AD244 alternators are PCM controlled in Express vans. It would be nice to know for sure and what model year it started with.

[WJones]

Originally Posted by markopolo

The PCM controls the alternator output from what I've read. (on newer models) For example it will increase idle speed to spin the alternator faster to meet demand when necessary.

PCM Controlled:
Large Red - main cable to battery
Small Red to PCM "Generator Turn On Signal"
Small Grey to PCM "Generator Field Duty Cycle Signal"

For my van the wiring is the same for the primary alternator and the auxiliary alternator if installed.

Not PCM Controlled (CS144):
Large Red "Bat" - main cable to battery
P (Phase) terminal - not used
L (Indicator Lamp) terminal - Brown wire
I/F (Ignition) terminal - not used - (L terminal is used in place of)
S (Sense battery voltage) terminal - not used

My guess is that the AD244 alternators are PCM controlled in Express vans. It would be nice to know for sure and what model year it started with.

On my 1999 chassis Express, I've got RPO code KW2 124 Amps, which, according to Rockauto is a CS144.
I checked other model years on Rockauto. At first I was under the impression the change to an ADxxx came with the 6L engine, but finally it was a bit before that. They appeared in 2001.
So, the Haynes manual wouldn't be much help if I wanted to troubleshoot my charging system
William

[booster]

Originally Posted by markopolo

The PCM controls the alternator output from what I've read. (on newer models) For example it will increase idle speed to spin the alternator faster to meet demand when necessary.

PCM Controlled:
Large Red - main cable to battery
Small Red to PCM "Generator Turn On Signal"
Small Grey to PCM "Generator Field Duty Cycle Signal"

For my van the wiring is the same for the primary alternator and the auxiliary alternator if installed.

Not PCM Controlled (CS144):
Large Red "Bat" - main cable to battery
P (Phase) terminal - not used
L (Indicator Lamp) terminal - Brown wire
I/F (Ignition) terminal - not used - (L terminal is used in place of)
S (Sense battery voltage) terminal - not used

My guess is that the AD244 alternators are PCM controlled in Express vans. It would be nice to know for sure and what model year it started with.

I just spent a bit of time trying to find the right area of our 07 factory service manual. They do a really poor job with wiring diagrams. No longer all in one place but spread out by section with poor indexing. Whatever, here is the wiring diagram for a 2007 diesel chevy with auxiliary battery.



It shows both alternators connected to both batteries.

Both alternators have internal regulators so the ECM does not control the voltage or charge current

The primary alternator works just like if there was only one, and the same as on the gas engine. It has an "on" signal from the ECM to turn it on. It has a "generator field duty cycle signal" back to the alternator, which is not used to control the alternator but is used to judge engine load from the alternator for the ECM to use in the idle characteristics calculations.

The auxiliary alternator looks to be a plain old single wire setup, but with a charge indicator signal back to the ECM.

[markopolo]

and I see the batteries are interconnected

-----------------------------------------------------
It looks like the alternator mix is:

2008 to current? - AD244 DR44G / DRII44G
2001 to 2007 - AD230 AD244
1996 to 2000 - CS130D CS144

That may not be 100% accurate but it does tell you that it is info that is good to know before there is a problem. Example: The CS130D end connector is different from the CS144 connector. My van has the same RPO code - KW2 - as William's van.

GM RPO code lookup and decoder http://www.classbforum.com/phpBB2/vi...php?f=9&t=1825

[booster]

Originally Posted by markopolo

and I see the batteries are interconnected

-----------------------------------------------------
It looks like the alternator mix is:

2008 to current? - AD244 DR44G / DRII44G
2001 to 2007 - AD230 AD244
1996 to 2000 - CS130D CS144

That may not be 100% accurate but it does tell you that it is info that is good to know before there is a problem. Example: The CS130D end connector is different from the CS144 connector. My van has the same RPO code - KW2 - as William's van.

GM RPO code lookup and decoder http://www.classbforum.com/phpBB2/vi...php?f=9&t=1825

When I was shopping for regulators for our alternator (2007 vintage AD244), the perpetual question was weather is was 4 or 2 wire plug on the alternator. The alternators a stock GM stuff, so they are used lots of places. Perhaps the 4 wire is the one that has the ECM controlling it.

I think the big thing to take away is that if the alternator has a built in regulator, and on Chevies at least you can see it easily, it is not controlled by the ECM.

I think the other thing that would need to be checked would be what regulators are in the two alternators you plan to use, and what the correct ones should be. Do they need to match, or should they be different? At least on the setup shown in the wiring diagram, it might pay to have the original one running on the factory 14.8v regulator (which gives about 14.4v), and the secondary one running on a 14.1v regulator (that gives about 13.9v). That way the ECM would get better information on electrical load because only the original alternator has a feed back to the ECM of output.

[markopolo]

All good points - thanks.

The second alternator project is on hold. I'll try the new slightly higher output alternator I bought on its own first and see how it performs.

---------------------------------------
a side note:

If anyone is looking for an online repair guide check to see if your library has an Electronic Resource section. I was browsing the local library system here today from home and it gives me access to something called "Auto Repair Reference Center". It actually has the installation and removal instructions with accurate diagrams for both the primary and auxiliary alternators for my 1997 diesel van.

Edit: Update - the "Auto Repair Reference Center" in the library system has good info. My van has a color coded Battery Junction Block under the hood. I was able to view that as part of the starting and charging circuit diagram. Now I know what the Orange, White and Blue label studs are used for and it allows me to download the diagram as a PDF.

[booster]

I have been collecting information on aftermarket alternators in case we decide to up our output to run the microwave more completely. I had a good discussion with a tech at DC Engineering about what they have to offer. From what I was able to find out, they have a good reputation for high output, durable stuff, mostly in the audio and military type markets. They have the typical upgraded Delco units, and also their own alternators which are made in conjunction with Denso. That is a good thing because the they can get a lot of Denso specific technology put into their stuff.

The Denso alternators are about 50% higher cost than the Delco style, and are in custom cases so they fit the various applications and also the Denso construction. The Denso alts are also much better at lower alternator speeds and don't lose as much from high temps, compared to the Delco units per all the specs. They have a 250 amp rated Denso style that will do 130 amps cold, 120 amps hot at the idle alternator speed of 1800 rpm that we have. It comes with a 14.8 volt internal regulator that I was told drops to about 14.4/14.5 after running a little while. He also said the GM 14.8 does the same thing, which would explain why we always see 14.3/14.4 going down the road. A lower voltage regulator is also available, rated at 14.4 volts, but he thought that is would run at under 14.0 volts going down the road, as it is most likely also a turn down type. If you buy one with the high voltage regulator and it runs too high, they will give you the lower voltage one, which is simple to put in, I was told.

If we decide to go for higher output, this is probably the one we would get. It is said to be a drop in.

https://www.dcpowerinc.com/fit/Chevr...37-250-xp.html

Be sure to check out the performance tab in the link, they have a complete curve by alternator speed, and all the rest of the details.

With so many really high output alternators available, you would really have to need a lot of power to make the double alternator or engine generator worthwhile, I think. If you have a high idle switch, it makes the single alternator even more attractive for the things we have been talking about lately. We don't have a high idle switch, and putting one on would cost almost as much as the DC Engineering alternator does, and be a lot more work to put in. I can see why Roadtrek does the generator on the E-trek, as they want to have 24 volts for the inverter designated batteries.

[eric1514]

Maybe I missed something, but why are you wanting to run the MW from your engine and not your generator?

[markopolo]

It would be for convenience and noise - the van is so much quieter. You pull into a rest stop and can heat up food before you shut off your engine etc.

I don't have a generator so it is a really nice option for me.

[booster]

Like Marco says, it will be way more convenient to use the van to run the microwave, when we don't have shore power. It also will allow some leeway on generator rules, I think, but we wouldn't push that as it would be inconsiderate many places. The van is so quiet, and it doesn't have the smelly exhaust, so it is much less of a problem with others. You also have to start the Onan, let it warm up a few minutes, use it, let it cool down a few minutes, so a 10 minute microwave run turns into double that time with the generator running. With the Onan, you also have to consider how often you are using it and the quality of the gas you happen to have in the van. We use ours sparingly, so we need to make sure we get preservative into it if it is going to be sitting more than a couple of weeks. We hope to get to the point where the generator is only used for air conditioning, which we also hope we will rarely need do to prudent selection of destinations. With the e-trek and CS Adventurous as examples, with other Roadtreks also getting the engine generator as options, I think you are going to see more and more of van engine power generation, often teamed up with solar. Generators will only be needed for air conditioning, when you don't have shore power, so I would think many folks will pass on them at that point.

[eric1514]

Originally Posted by booster

...It also will allow some leeway on generator rules,...

Yeah, that's the part I'm not too keen about, violating the spirit of the law. The rest of it I'm on board with. My generator is many times more trouble than it's worth. It's expensive, heavy, noisy and temperamental. Unfortunately, here in AZ, it's also a necessity for the AC if I boon-dock.

Do you think with this upgraded alternator that you would be able to run an electric water heater like that found in the Ranger RT or the Travato?

[booster]

Originally Posted by eric1514

Yeah, that's the part I'm not too keen about, violating the spirit of the law. The rest of it I'm on board with. My generator is many times more trouble than it's worth. It's expensive, heavy, noisy and temperamental. Unfortunately, here in AZ, it's also a necessity for the AC if I boon-dock.

Do you think with this upgraded alternator that you would be able to run an electric water heater like that found in the Ranger RT or the Travato?

I hear you on the rules, and the spirit of them, that is why we will be very careful with that part so as not to impact others. It really isn't all that new an issue, either, I think. We often see tent campers running their vehicles to warm up on cold rainy days and night, and some even run coffee pots and such from them, when it is wet outside. The good part would be to be able to cook something in the micro while taking the short trip to well for water or whatever. If these systems become more prevalent, I would certainly think the rules will quickly be updated to cover them in the no generator zones.

I don't know how much power the water heaters take, but the 250 amp alternator I had in the link would have over 100 amps, or 1200 watts available at idle. The 300 amp version would have over 150 amps or 1800 watts, as long as you had the wiring to carry it.

[eric1514]

Originally Posted by booster

...I don't know how much power the water heaters take, but the 250 amp alternator I had in the link would have over 100 amps, or 1200 watts available at idle. The 300 amp version would have over 150 amps or 1800 watts, as long as you had the wiring to carry it.

The Eemax WH in the Ranger is 1440 watts, so it seems the 300 amp version would work, provided, like you say, the wires are large enough. It certainly is a cheaper alternative than a generator and the weight savings is huge. I wonder what it does to your mileage just driving down the road.

[booster]

Alternators theoretically should only increase load on the engine based on how much power they are generating, regardless of their size. It was one of the questions I asked DC Engineering when I talked to them and they said the same thing. Like all things, it is probably almost always true, but might have exceptions. There may be more slightly more friction from larger brushes in a huge alternator, or from the bigger bearings needed, for instance. In reality, I would not expect a noticeable difference in economy, unless you were running a big load while driving, like the mentioned water heater, or if you had lots of mostly dead batteries. Then you might see something. If you are running the engine while stopped to run things, it will increase your fuel use, and if you don't allow for that, it will lower your overall mileage calculation, even though the mileage when actually driving might be the same.

[booster]

May or may not apply to anyone else, but today I was getting stuff back into the van, hoping we can get out pretty soon for some trial runs, and when I went through the traveling tool kit, I noticed my fuse container and realized I had added a bunch of fuses to the van that I didn't have spares for in the toolkit. I had to add at least a half dozen different sizes, and through in one of the 80 amp circuit breakers also. Also replaced the Harbor Freight meter with my old 20 year old Fluke, which is still more accurate than the Harbor Freight one was new.

You usually don't need a fuse unless something else breaks, but it sure is nice to have them along when you are a longs ways from nowhere, and need to get running.

[booster]

Do you ever get grief about tools that are rarely, almost never, used? I do, mostly from myself, sometimes from others

The snowblower from **** adventure continued today, as I finally gave up on being able to get the wheels off it with them on the blower. I was very uneasy about putting lots of torch heat on things that were very oily, gas tank close, etc. I had made two different puller adapters and an 8 ton NAPA puller wouldn't budge the wheels on the shaft.

Finally broke down and ordered a new axle, about $60 to the door. Cut the old axle with the recip saw, which was more difficult than expected as the shaft appeared to be 1050 shafting or like it. Slid them out from both ends.

I then went to the very, very, rarely used 20 ton hydraulic press (Harbor Freight for $160 when I got it years ago), and rigged up the right supports and drivers to push out the axles. I wound up with the pump jack just tickling the bypass by the time I got them to move, so this little 3/4" shaft took enough force to lift 4 of our Roatreks to move it. It did the major stick slip all the way out, which really sucks when you need that many drivers. The wheel hub is upwards of 4", so there is a lot of room for rust. Months of penetrating oil of all brands had only gone in maybe 1/4".

Interesting thing is that once the old shaft was out, the new shaft slid right into the wheels, with no cleaning of them. All the corrosion was on the shaft, which makes sense, because high strength steels generally are more prone to rusting.

Now the 20 ton press can go back in hibernation for another 5 years!

[markopolo]

I'd rather buy the tool and DIY when possible rather than have someone else do a job. Once you have the tool then you find uses for it even if only occasionally. I've sold a few tools (like a hardwood floor nailer) that I didn't think I'd need again but that is a rare occurrence.

I have to work on my snowblower also. It spit out pieces of a belt at the end of the last cleanup. Thank goodness it failed at the end of the season!

MVP in my list of tools: Multimeter

Some tools, like an electric planer, don't get used much but are so handy when needed.

[booster]

That's funny-one of the only tools I have ever sold was a flooring nailer, also. I never want to do that job again. We did the full thickness, sand and finish type. What a pain and mess, plus hard on the body.