dandick66

To determine if the pump is faulty, just switch the wires with one of the other pumps. I’m betting the valve is stuck. Keep tapping on it while the pump is running. As far as running on electric or diesel, I thought if you have both switches on, then if the electric can’t keep up, the diesel burner will kick in to supplement.

My 2012 Diplomat generator uses the house batteries for starting. This is a poor design as the generator struggles to start from them. I’ve seen posts where users add a separate starting battery and isolator up front at the generator. I was looking into this when I thought I’d look at the possibility of moving the starting cable from the house batteries to the chassis batteries. I found where the generator cable is connected to the house battery bus and found an empty connection on the chassis bus. I can make a jumper/extension for the cable and get it moved, but I discovered something with the power that I don’t understand. When I turn the house or chassis disconnect switches off, I still read voltage on both buses. However, if I turn both disconnects off, I only get voltage on the respective buses when I turn the chassis or house switch on. If I turn both switches on, after about 30 seconds I hear the Big Boy energize and then I get the same symptoms - if I turn either switch off, there is still voltage on the buses. I thought the Big about was an isolator and would only pass power when charging, or when you push the battery boost switch.

Richard, I found info on the Executive and it looks like maybe that sensor in your shower/toilet room, may be for the middle AC, which would be zone 2 on your bedroom thermostat. You could set the zone 2 temp to a few degrees above ambient and then go to the sensor and breathe real heavy on it, or use a hair dryer on low setting. That will raise the temp and if the middle AC kicks on, then you know that’s the right sensor. As far as the AGS, there has to be a sensor somewhere. Have you tried testing it? Try setting the start temp to the lowest setting and see if it starts the generator.

Richard, Since it’s raining today, I decided to do a little research. Your coach HVAC layout is different than mine. Here’s what I think I’ve figured out. If you have the Comfortaire system, you should have 2 thermostats. The thermostats have small temperature sensors on the bottom. The front Comfortair controls the front AC. The bedroom Comfortair controls the mid and rear AC units. So, the temperature sensor you found in the amidships bathroom is probably for the AGS. Good luck. Dan

Last year I thought I might have had a bad expansion valve and did some research. Fortunately, that wasn’t my problem. The company Monaco used, SCS, was sold to Victory Climate Systems. They didn’t have very good records, but I’ve attached a screenshot of the PDF they sent. From what I understand, the biggest concern is getting a valve with the correct fitting sizes. I’m sure someone on here has a lot of AC expertise and can chime in.

Richard, On my 2012 Diplomat the OTA antenna and cable use the same coax. You should have a small box (amplifier) for the OTA antenna. When this amp is energized it boosts the OTA signal. If you connect to cable, make sure that switch is off, otherwise the OTA signal will interfere with the cable signal. Like others have said, change the input on the TV to “air” or “cable “ as appropriate. I have connections for cable and external satellite in the water service bay. For troubleshooting purposes, if you don’t have cable service, you can hook up an older VCR or DVD that has a coax output to the cable input in the service bay. If you switch a TV to cable, you should be able to view the output of that VCR or DVD.

No shortages here in the Tidewater Virginia area. Not sure where you’re planning on going, but like others have said, top off frequently.

Richard, Does the BTS port on the inverter have an RJ-11 plug in it (see attached photo - it’s upside down because that’s the way the inverter is mounted in my coach. It’s the Yellow port.)? As far as the temp sensor, what you might want to do is locate the other room sensors in the coach and see what shape they are. If the one in the bathroom is different, then you’ll know it’s the Magnum temp sensor. The Magnum temp sensor looks completely different on my coach. Look at the photo I sent the other day. The smaller sensor, to the right and below the Remote panel is the room sensor. I have 4 in the coach and they are all at the same height (54 inches.) from the deck. For what it’s worth, I’d get the BTS and temp sensor issues figured out before you install the new remote and AGS-N. That way if you have a problem, you’ll know it worked before the new parts were installed. I’m not sure how important the BTS is. I’m sure if you ask Magnum, they’ll say you have to have it. I would think that it just makes sure the batteries don’t get too hot, which is probably a good thing. Dan One more thing…. Here’s a copy of the page from the remote manual. Under tech menu, you can view battery temp and AGS temp. If you don’t get readings then it means nothing is connected or it’s broke. I don’t know if your remote has these features. Dan

Richard, I have the MS2812. As far as I know the only difference is 1 is 2000 watts and the other is 2800 watts. I’ve attached few photos of the different components. The inside temp sensor is in the photo with the remote. It’s the device that looks like a hockey mask. You should be able to see the temperature change on your display if you blow some warm/hot air on the sensor. The BTS may be connected to the chassis batteries. If so, you’ll want to move it to the house batteries. Also, the remote should be sensing the house batteries, not the chassis batteries. They are what will trigger the AGS if they drop the voltage too low. Something else I learned the hard way. I’ve owned this coach for over 4 years and had never used the AGS. I hit the test button and it worked fine. Then I started to mess around with the settings and tried the temp start feature. I breathed on the sensor and the temp came up and the generator started as it was supposed to. Then I unplugged from shore power and then went back in the morning and the voltage was down a little, so I fired up the toaster and microwave and a hair dryer and watched the voltage drop and the generator did not start. I opened up the AGS N module and didn’t see anything wrong. I called Magnum and they said I needed a new board. Well I remembered seeing 3 miniature relays on that board. It got me wondering if there was a relay for test, temperature and voltage. I have seen this type of relay stick in other applications, so I tapped on each one with a screwdriver handle. That did the trick. The generator now starts on temp and voltage. The moral of the story is don’t rely completely on the test function. Try temp and voltage and make sure it starts. Hope this helps. Dan

Well, I don’t think that’s the case since the engine serial number matches that of the build sheet.

In my never ending quest to find air leaks, I removed the engine access panel in the rear bath. After dusting off the valve cover, this label was revealed. I’ve never seen anything like this before.

As the politicians say, “That’s a very good question “. The default setting is 10.0 volts. However, that doesn’t work for me. I have an Aquahot, and it shuts down if the voltage drops below 12.0 volts. Also, my generator uses the house batteries for starting and because of the length of the cable run from the batteries to the generator, it won’t start below 12.2 volts. So, that’s where I have my LBCO set. As a side note, I will be installing an auxiliary battery up near the generator, just for starting the generator. Then I will probably lower the LBCO. As long as it’s summer and I’m not using the Aquahot, I can lower the LBCO below 12 volts.

Turn the inverter off at the remote panel. Also, you can raise the low battery cut off (LBCO) to 12.2, that way the batteries won’t drain and they should hold the charge until you get it back from the shop.

Before you tackle this job, you may want to get the antifreeze/fluid. Good luck finding it at a decent price. It looks like the Camco brand is no longer available, and the shipping on other brands is very expensive.

This post has been very informative. I did some research and found that there is another type of PEX - Type C, used in radiant flooring, and it has a higher chlorine tolerance. I also discovered that PEX has a max temperature rating off 180F. On my coach, there are several feet of heater hose coming out of the engine water pump. Then there is a fitting that transitions to PEX that runs all the way up front to the heater core and then another fitting to change back to rubber heater hose. The return line is just the opposite. A few years ago mine separated at the fitting and there was not enough slack to make a repair, so I removed the fitting, slipped 3/4 inch heater hose over the 5/8 PEX and then installed a 3/4-5/8 barb fitting and connected it to the water pump hose. Now I’m wondering why Monaco used PEX when it’s max temperature rating is 180F. The engine water temp is much higher than that. Looking at the specs for PEX, the max temperature does increase with lower pressure, but it stops at 180F. I don’t know if all DP’s are configured this way, or whether my coach is “special “, since it was made by Navistar.

I swear my coach is possessed! This weekend I started it up and intended to take air pressure readings and post them. First off, my coach has the Medallion system and I cannot read any pressures unless the engine is running and the low air alarm is off. So, I installed a dual-reading analog gauge that I can read all the time. The pressure built up to 127 PSI and the compressor cut off. The pressure dropped 10 PSI and then stabilized. Remember how I said it dropped about 1 PSI every 15 seconds? Well, it stopped doing that. The pressure dropped 1 PSI after about 5 minutes. I ended up shutting the engine off and checking the analog gauges every once in a while. The pressure dropped very slowly, but still went down 90 PSI in less than 24 hours. The good news is the somewhat rapid pressure drop appears to have stopped. The bad news is I still have a significant leak. The only thing I can think of that may have stopped the every 15 second drop, is that I changed fuel filters a couple of weeks ago. I have the Maxxforce 10 engine and the fuel filter is on the engine and I need to remove the floor access plate to get to it. While I had the access plate off I looked at any and all hoses and lines to check for chafing, etc. I think I may (must) have moved an air line and maybe it reseated itself on the push to connect fitting. I will pull the access plate and double check everything. I can see my rear air tank and it is more or less directly above the differential, so I am going to have to make some ramps and blocks for the suspension so I can fit under there. The front tank is very accessible and I sprayed it and looked for leaks and didn’t find any.

You could get some 1/2 inch rubber heater hose and slip it over the PEX and hose clamp it. That’s similar to what I had to do on mine although it was 5/8 PEX. The OD of 5/8 PEX is 3/4 inch, so I slipped 3/4 inch heater hose over the PEX. The 5/8 PEX was difficult to find unless I want to buy a 300 ft roll. The hardware stores stock 1/2 and 3/4. Apparently, 5/8 is used a lot in heated flooring applications.

Dryer is very easy to access. There is a door aft of the tag axle, driver side, that gives access to the AC condenser, air dryer and fuel filter/water separator. Thanks for the documents. I’ll look them over tonight.

It seems to drop the pressure whether the engine is running or not. It drops to around 40 PSI overnight and drops to zero within 36 hours. I’ve also noticed a significant “squat” in the rear after the coach sits for over a couple of weeks without running. I’m thinking this is a leak in the Valid leveling system or the rear air bags. I’m going to start it up tomorrow and let it build pressure, then measure the rear height and see how quick it drops. I think I’m going to tackle this in this order. 1. Bypass dryer 2. Replace charging valve. 3. Remove and inspect/repair/replace PPV’s. I’ll post my findings.

Yes, I’ve tried it with park brake applied and released, and service brake applied and released. It doesn’t make any difference.

I’m trying to better understand exactly how this valve works. My understanding is that once the pressure builds up (in my case 128 PSI), the governor cuts off the compressor and this valve allows the air in the tank to back flow for a 10 PSI drop. My system drops the 10 PSI in about 30 seconds, but it continues to drop probably 1 PSI every 15 seconds. When it drops another 10 PSI, the compressor kicks in and the cycle starts all over. Looking at the WABCO website description of this valve, it says the valve allows back flow equivalent to a .015 diameter orifice for pressures greater than 110 PSI and .05 diameter orifice for pressures greater than 105 PSI. There is no back flow for pressures below 90 PSI. What I don’t understand is how it gets the 10 PSI drop. Unless I’m missing something, the valve will allow the back flow all the way down to 90 PSI.

Check your owners manual. Mine says both battery sets charge while on shore power, generator and alternator. Put a volt meter on the batteries while unplugged. Then plug into shore power. You should see an increase in voltage on both sets if the setup is designed to charge both. You can also unplug from shore power and start the engine to verify it charges both sets from the alternator.

Richard, Glad you made it back safely. I’m sure you’ll get all of the bugs worked out. Your post-mortem was excellent. It’s unfortunate that there are so many “wanna be” inspectors. Dan

I bought mine used late 2017. I wasn’t aware of the Maxxforce problems, or I probably would have not bought it. However, like I said, I haven’t had any major problems (I did have to replace the ACM - after treatment control module- but that wasn’t a show stopper. Let’s hope GKwarner gets his problem fixed quickly. Dan

For the headlight switch, get some electric contact cleaner spray and pull the switch to turn the lights on. Wrap a rag around the switch and then spray the cleaner on the shaft as you rotate and push/pull it. That might save you having to pull the switch. If you have to remove the switch, you’ll probably have to get behind it and push a little button on the side of the switch so you can remove the shaft. Then you can access the retaining nut.