Diplomat Fixes & Solutions

Sound System: Monaco features the Magnadyne M9900DVDS radio/CD/DVD player along with the AMC XSA 5.1 Pro Home Theater Amplifier as their sound entertainment system. This is a full featured system with stereo AM/FM/Weather/Satellite radio output to a 5.1 surround sound home theater amp. It also plays CDs, CDRs, and audio or video DVDs. The DVD player is routed to the flat screen TV. An A/V auxiliary input and two A/V aux outputs offer plenty of flexibility for other audio and video components. I also like the large buttons, which are easy to access while driving. The features are great. The problem is, the system just doesn't work very well. Several owners have reported that the DVD player begins to skip after a while, and almost all owners have experienced an annoying audio hum in the sound system inflicted by the coach generator, alternator, inverter/charger, or even florescent lights in the coach.

In 2007, in an attempt to fix the hum problem, Monaco issued Service Bulletin 07-07-08, which installed a 120v converter for powering the system while parked, and a relay controlled switch box for reverting to 12v power, and bypassing the home theater amp, while underway. The "fix" is cumbersome, taking up way too much room in the A/V cabinet, and it doesn't resolve the problem. I had these components installed and have since removed them. What did resolve the hum problem for me was the addition of the Pyramid NS-20 15a noise suppressor isolation transformer, pictured here. It is placed in the audio lines between the radio and the home theater amp. Proper installation requires gender change adaptors for the RCA plugs. It also helps to reduce the left/right speaker volume controls on the home theater amp. (All volume controls on the amp are originally set at max rotation.) These controls are found behind plastic covers on the side of the amp.

DVD Freezing Problem: Many owners have complained about the DVD player in the Magnadyne M9900DVDS stopping or freezing during a movie. Magnadyne says this is due to a faulty power connector. (See the diagram to the right.) The pins for the yellow and black power wires fit onto the pins on the far left side of the plug (opposite the red arrow). These two holes on the harness terminal are larger than the rest, but the pins on the radio are not, causing a loose power connection. Magnadyne told me that the problem exhibits itself during DVD play due to the higher current draw at that time. The "fix" is to remove the connector and carefully bend the metal tabs in these two holes so as to allow better contact. I never experienced the problem, so I cannot verify the validity of this solution. If anyone can, please contact me.

I have since upgraded to the Magnadyne M1-LCD head unit, which has a large touch screen and more features than the M9900DVDS. The harness is exactly the same, but the two power pins are larger on this unit so that good contact is made with the harness. Therefore the new M1-LCD unit should not exhibit this problem.

Wiper Problem: Many owners of 2006-2007 Camelots, Diplomats, Endeavors and similar Monaco coaches are aware of a problem with the wiper assembly. In 2006 Monaco went to the one-piece "Panaview" windshield on the raised rail chassis coaches. At the same time, they also went to horizontally mounted wipers with large 32" blades. Although the vender they used for the wiper assembly, AM Equipment, of Jefferson, OR, is a quality supplier of OEM wiper systems, the assembly they used for the 2006 and 2007 coaches was simply not up to the task of "pushing" the longer heavier arms on that huge windshield. In addition, the driver's side wiper tends to fly off the left side of the windshield, which puts additional stress on the pivot arm attachment point, as well as the light weight plastic ball-and-socket joints that are used for the inside linkage. As a result the linkage tends to come apart, and failure rate on the entire assembly is a problem.

The good news is that when the problem was realized, AM Equipment went to work to develop a new heavier duty Tandem Radial Wiper System that is up to the task of handling the huge one-piece windshields that Monaco is now using. It has a strong tubular construction with bolted joints replacing the plastic ball-and-sockets. The diameter of the pivot arms are also about 50% larger. Monaco started installing the new system on all 2008 coaches, and also in 2008, they issued a recall for 2006-2007 Diplomats and Endeavors to upgrade the faulty wiper systems to the new one described here.

I received one of the new wiper assemblies under warranty in late 2007, but since Monaco originally considered it an "upgrade" I was responsible for the cost of installation. Later, in February of 2008 Monaco announced a recall to begin installing the improved system on all 2006 and 2007 Diplomats and Endeavors. Both Monaco and AM Equipment offered excellent support throughout the process. AM Equipment produced an assembly that was almost a "slide-in" replacement for the original system. The only significant modification that had to be done to the coach was to ream the holes in the front cap larger to accommodate the larger pivot arms on the new assembly. Stoltzfus did a very clean and professional job of installation. The new wiper system looks good on the coach, and works very well.

See pictures below. Click on the pictures for a larger view, click again to expand. Close window when finished viewing.

Front View

Wiper Arms

Motor & Mount

Right Pivot Arm Linkage

Mid Chassis Harness Battery Connectors: From 2007 on, Monaco splits the chassis harness into three sections. There's a "mid chassis harness that runs the length of the coach. It contains all the chassis wiring that needs to run front to back. Each end of the harness consists of two 42-pin connectors and two Deutch Jiffy Splice connectors for the two battery cables that run to the front of the coach. All four connectors on each end mate with the the front chassis harness and the rear chassis harness.


Above is a diagram of the mid chassis harness. To the right is an actual photo showing the two rear 42 pin connectors and the two Deutch battery splices connectors (before I replaced the battery splices).

The Jiffy Splice connectors look like the the picture on the above left that I took of one of my actual connectors after it was removed from the coach. A male and female pin are pushed together inside a metal sleeve, which is contained inside an outer silicon insulation shell. You can clearly see these in the upper right harness photograph. When assembling this connector, you are supposed to push the pins together until they lock in place and you hear an audible click. The pins fit very tightly and it can sometimes be extremely difficult to get them to mate properly inside the sleeve. Consequently, sometimes the Monaco builders do not get them pushed together to the locking position while assembling the coach. When this happens, the pins can arc inside the sleeve. In the picture to the left, you can see a hole on the left side of the metal sleeve burned by arcing current. Three of my four connectors had burn holes similar to this one.

If not locked in place, the pins can also work apart to the point where they completely separate. The consequence is that you can loose all power to the front of the coach (including the ignition) and the coach simply shuts down while you are driving. This has happened to me twice. The second time it happened, I suspected what the problem was. After verifying the failure by checking voltages at the lugs in the front run bay, I was able to perform a "jury-rig fix" along the side of the road by connecting the two battery input cables with a jumper, effectively by-passing the defective cable. The black jumper wire I installed can be seen in the above photo to the right. I am showing this picture so that others might know where to install a jumper for a temporary road-side fix, should this problem happen to someone else.

My permanent solution was to have my local mechanic replace all four Jiffy-Splice connectors with solid splice links that were both crimped and soldered. Then the splices were wrapped in heat shrink sleeves and nylon cable loom taped in place on each end. I should never have this problem again. Here is a picture of the front end of the harness that I took during the repair. It's really hard to reach. The coach was up on the lift you see here.

Low Water Pressure at Kitchen Faucet: Here is a great little "fix" that I cannot take credit for. One of the members on the iRV2 Monaco Owner's Forum broke the sprayer nozzle on his kitchen sink faucet, and was posting that exact replacements could be found at Home Depot. Another poster noted that inside the faucet head was a back-flow arrestor valve. You can see this valve nested inside the nozzle in the the picture. The purpose of the valve is to prevent sink water from entering the fresh water supply, should you dunk the pull-out faucet nozzle into the sink. However the valve forces the water flow through a tiny hole which significantly reduces the pressure. Removal of the valve assembly eliminates the low-pressure problem. I was able to fish it out with a large pin.

Here are all the individual parts of that valve. It's little wonder that the pressure at an RV sink is low with that valve in place. Most home water pressure is probably strong enough to properly activate the mechanism.

Full-Wall Slide Not Closing Tightly on One End: This fix was relayed to me by Lew Felton, another SFT owner, who was given this information from Monaco Tech Support. The SFT floor plan on the Diplomat and Endeavor has a huge full-wall slide that is powered by hydraulic rams. Sometimes the rams get out of sync, causing the slide not to close as tightly as it should on one end or the other. With the length of this slide, it would only take a small amount of difference between the rams to cause an alignment problem.

The solution is to retract the slide and hold the retract button for 20 seconds after the slide is in and stopped. Then wait wait about a minute to let the hydraulic pump cool down. Now extend the slide out and again hold the button down 20 seconds after the slide is fully extended. According to Monaco, this procedure will re-sync the hydraulic rams.