Auto Genset start (AGS)

[Sixpack98]

Our Magnum charger/inverter came with the auto genset option(AGS) but autostart only works when the salesman switch is in the on position. Is this the standard configuration? When the coach is in storage I'm not interested in a bunch of non-essential parasitic loads draining the house batteries and I think my preference is to allow genset start regardless of the salesman switch position.

Also, there was a series of electrical documents on this forum but I no longer see them. Have they been removed? There are 2 wires that connect to pin 3 (12v DC sense) on the gen and power I/O connector of the AGS module. Obviously one goes to the salesman switch but without the house schmetic I have no way of knowing what the other wire connects to. Does anyone know or have access to the generator system electrical schmetic.

thanks in advance
mark

[itdave]

Second question first I believe that they were removed by the Forum owner for some reason.

It does make some sense that the AGS might not work with salesman switch in off position but it is what the salesman solenoid disconnects not the switch itself. I guess the AGS gets it power from one of the circuits that gets turned off when the solenoid is open. I have the manual and it shows that on the 8 connector on the AGS pin 3 connects to plus 12 volts from the battery and pin 4 goes to negative 12 volts on the battery. I am not sure I would want my generator starting while the coach is in storage. I turn off both disconnect switches in the battery bay and with a solar panel connected to the chassis battery I am able to start the coach after 1 month of storage.

[Sixpack98]

Quote:

Originally Posted by itdave ......... I have the manual and it shows that on the 8 connector on the AGS pin 3 connects to plus 12 volts from the battery and pin 4 goes to negative 12 volts on the battery...........

Dave,
My AGS manual shows the same but apparently Monaco derives the +12v through the salesman switch. That said, there are actualy 2 wires connected to pin 3 and I don't know where the second wire goes to. Monaco tech support was no help.
We are leaving for about a month (non-RV) and don't have solar or a reliable person to run the genset while we are gone. I could disconnect the house batts but not a big fan of disconnecting the chassis batts for that length of time. I don't have a problem running the genset without me being there - that's the purpose of the AGS.

So, if someone knows where the second wire goes to it would be appreciated.

mark

[akadeadeye]

What is the Salesman Switch?

Don

[ShapeShifter]

Quote:

Originally Posted by Sixpack98 We are leaving for about a month (non-RV) and don't have solar or a reliable person to run the genset while we are gone. I could disconnect the house batts but not a big fan of disconnecting the chassis batts for that length of time.

You don't have a problem shutting off the house batteries, but don't want to shut off the chassis batteries?

If you turn off the house batteries, they should have no problem riding out a month in storage. And unless you have done some modifications like a BIRD relay or added an EchoCharge or Trick-L-Start, odds are that the generator won't charge the chassis batteries. So I don't think there will be any point of trying to run the generator during that month: the house batteries won't get charged since they're turned off, and the chassis batteries won't get charged since they're not normally charged by the generator or shore power.

Even if you leave the house batteries on (regardless of the salesman switch) unless you're going to do more electrical mods to let the chassis batteries charge from the generator, I question whether you will gain any benefit of periodically running the generator while in storage.

Personally, I think your best bet is a solar charger, or just turning off both battery banks. What is the concern about turning off the chassis for a month? I think the worst that may happen is it might forget some tuning parameters, and it may take a few days of driving for it to re-learn the way you normally drive.





Also, I'm sure you're aware, but it doesn't hurt to say that even with the salesman switch off, there are still some parasitic loads on the house batteries -- I'll bet that they are most of the parasitic loads you are worried about. On my rig, these loads are NOT turned off by the salesman switch:

• Radio Memory
• Refer
• Air Leveling (an option I don't have)
• LP/CO Detector
• System Heat Snap Disc
• House Read Out

The things that are switched off by the salesman switch are things like the power seats, power hose/cord reels, slideouts, and other things that don't take power unless you hold the switch, and then the various lights, 12-volt power outlets, furnace and A/C controls, and fans which are easy to turn off and are noticeable when left on. About the only thing I see on my rig's salesman switch list that isn't something that you can easily tell is on is the home theater amplifier (you need to make sure the unmarked switch in the overhead compartment is in the right position) the rear radio (I don't have one) and the EMS and AGS.



So, other than the EMS and AGS, it seems to me that the things controlled by the salesman switch aren't the parasitic loads one normally worries about in storage, while the things that do really count in storage aren't controlled by the salesman switch.

So given all that, are you sure you want to make the change to keep the AGS alive?

Quote:

Originally Posted by akadeadeye What is the Salesman Switch?

The battery cut-off switch by the front door. Named as such since can be used by a salesman after giving a tour of the rig, and by hitting that he can be sure that the customers taking the tour didn't leave on any lights, air conditioning, heat, etc. But unlike the main battery disconnect switch in the battery bay, the truly important loads (refer, water bay freeze protection, CO/LP alarm, etc.) still have power. The switch is not designed for long term storage (since it leaves some parasitic loads connected) its purpose is to cut off most loads so the batteries don't drain when leaving the rig overnight or for a few days.

[ShapeShifter]

Quote:

Originally Posted by Sixpack98 My AGS manual shows the same but apparently Monaco derives the +12v through the salesman switch.

Assuming you've not been dissuaded by the previous post, the AGS is fed from a fuse in the interior fuse panel, which is usually in a rear closet. This entire panel is fed from a 50 amp circuit breaker in the front run fuse panel, which is in turn fed by the relay for the salesman switch, which is in turn fed from the house battery disconnect switch.

Quote:

So, if someone knows where the second wire goes to it would be appreciated.

Unfortunately, the diagram I have shows just a single wire going from pin 3 of the AGS module to the P426 connector that attaches directly to the interior fuse panel, and gets it's power from fuse #17. (That same diagram shows the interior fuse panel getting its power directly from the house battery, but we know that's wrong since the power first goes through a breaker and the salesman switch relay -- they appear to have taken some liberties in "simplifying" that portion of the diagram.)

[itdave]

Mark,
I regularly turn off both of the house and chassis batteries using the disconnect switches. I have not run into any problems. Just wondering will you don't want to disconnect the chassis?

[Sixpack98]

Quote:

Originally Posted by itdave Mark, I regularly turn off both of the house and chassis batteries using the disconnect switches. I have not run into any problems. Just wondering will you don't want to disconnect the chassis?

My concern is the possibility of the engine ECM and the Transmission control module losing parameters and settings due to prolonged loss of power. I do understand it is a remote possibility and both control modules are designed with non-volatile memory but I've seen too many things go south in a MH that defy explanation or logic and theoretically not supposed to fail in that manner.

[Sixpack98]

ShapeShifter,
Thanks for the informative post. I do have the BIRD modification and most of the 8 amp draw as shown on the Magnum panel is through the BIRD to the chassis battery.
It sounds like the '07 End wiring is different, in many regards, than the '06 End. I kinda think the elusive 2nd wire on pin 3 of the AGS on my '06 may be an option around the salesman switch. Your suggestions have a lot of merit and long term solar may be a good addition when we get back. Time has run out to install solar now and probably the best option now will be to switch off house and chassis batts and hope for the best. Our old storage facility had 110 v 30 amp so I only had to worry about battery water and watch out for overcharging (which never happened).

[itdave]

Mark,
One idea might be to get a small solar powered battery maintainer. I see some 4 watt ones for under 50 and 5 to 10 watt for under 100. I think either would be sufficient to take care of the parasitic loads on the chassis batteries.

[Lukeaa]

I second itdave's suggestion for a solar panel. I have a solar system just for this issue and it has been worth the money to never come back to a coach in storage that has dead batteries. I would recommend a minimum of 50 watts to cover those cloudy winter days when panels do not produce much electricity. The solar system is transferrable to all of your future coaches, so the cost is spread over the rest of your RVing career.