klcdenver

I had the same problem on my 2003 Dip. I removed the panel and used thin aluminum epoxied to the underside for strength. I then used a 3M product called di-noc. It is self sticking and you can use a heat gun to really shrink it to a perfect fit. It comes in many colors and designs. Available on eBay and Amazon.

Here is a trouble shooting guide.

Air conditioner troubleshooting.pdf

Tom not to bust your chops but the 2007 Diplomat does have 2 temp sensors. The front one is right behind the passenger window just like the picture he posted. 
 

I would go up top and remove the shroud and wash out the coils with a water hose. Also check the inside of the shroud to make sure it has foam pressing against the top of the coils to separate intake and discharge air. Sounds like it is getting hot and the over temp switch is shutting it down. You might also do a hard reset on the 5 button thermostat control.

You should also check the coils to see if it is freezing up. When it shuts down remove the inside white box from the ceiling and see if those coils are froze over. There is also a thermostat with a brown wire on it and it should be stuck in those coils also. They are notorious for falling out.

Since you say running normal and power is normal probably just a indication/gauge problem. You can get a Scan D Gauge and it has a window that will give you turbo boost. It is a simple setup and you can get many different readings from it.

Try and get you a Scan D Gauge. This way you can see what the code was and make a better decision. You can probably pick one up at a local parts store or get it shipped in  next day. Much cheaper than going to shop to get your fault codes read.

Maybe a temp probe for fire extinguishing system.

The top left is the tailpipe. I used stainless flex from the turbo down to the piece in front of the muffler with clamps. You will need to build a hanger where the old muffler was to support the new system. You will also be about 30 pounds lighter with a setup like this. I can take this off in about 5 minutes and gives you a lot off access to get that side and rear of engine also.

I installed a Turbine AT4040 by Aero Exhaust . It is a quit or quieter than the stock muffler plus 25 to 30 ponds lighter. I am very happy with it. Sorry cannot get a link to paste that will open.

The installation of the Houghton is about the same as the Dometic. No modifications required. You just keep the control board from the Dometic so you can control the furnace. The Houghton has a remote control to control it. Here is a link describing my installation.

Jim,

I also have a 2007 Diplomat. 2 years ago I replaced my rear Dometic Penguin. I have the silencer on it also. I recently replaced the front unit with the Houghton which is about half the price of a Dometic. I just finished a 2 week trip using heat pump and A/C. The Houghton is a lot quieter than the Dometic. If you went with the Houghton you can also keep your current thermostat to control your 2 furnaces. Just food for thought. 

Did the Dometic you removed have a heat pump also?

Which Houghton model have you installed? I have the A3800 and I do not think it will interface with a Dometic thermostat. You have to use the remote or install Houghton wall pad controller.

I suggest you look at previous post under AC, Heating , and Cooling titled Houghton Install/Thermostat Dead. 

Try holding the bushing with vice grips. They have more rigid teeth than a vice. Ace Hardware usually has a pretty good assortment of bushings.

I think you push in turn about a 1/4 turn

What kind of Air conditioner and its model number would help. 

Sorry I am not good with linking and all that. I have attached a picture of what I used. You will have to cut slot/hole in to the box to insert the wires. You will also need to drill a few holes to mount the inserts to hold the control board. Call me or pm me if I can help you more.

Gary you are welcome. If the Houghton holds up in the long run it will be a great improvement. 

By leaving the 12volt in it keeps the 5 button control panel working the front furnace plus the rear penguin in all modes. 

I have finished the installation of the Houghton. In the black box attached is only 12 volt wiring and temp sensor and the RJ 11 communication lines. I bought the box off Amazon. I had to modify the return air and forced conditioned air separator, picture attached. I had to make the attach bolts out of some all thread rod (#8x1.25). I made them  9” long and just welded a nut on one end to have a hex head. 
 

Now for the good part. My old penguin 13,500 BTU with a wacko silencer was 58 decibels. It would heat to 106 degrees and cool to 39 degrees in the duck work. The Houghton is 53 decibels. It heats to 112 degrees and cools to 33 degrees in the duct work. I took the temps in the same place for both. It is much quieter on the outside versus the penguin's also.

I should have included this picture also which is the control board and wiring.

It kinda sounds like it is overheating. Clean your filter and make sure no obstructions on return air. Take shroud off up top and make sure coils or not plugged up with dirt and leaves.

Which AC units and size do you have and a is your control panel a 5 button or CCC2?

I am going to summarize what I did to rectify and get things to work on my 2007 Monaco Diplomat 40SKQ. This is not going to apply to models above a Diplomat as best I can tell. The Diplomat does not have aqua heat and some of the fancy things. It only has 2 Penguin II's originally both being 13,500 BTU. If you have upgraded to 15000 BTU your control boards are located inside the unit on the roof. The 13,500 BTU units control boards are located in the plenum between the roof unit and the air diverter box. The communication system to operate the 5 Button Control (standard on Diplomat) for the HVAC system is 12 Volts, AC power has nothing to do with it. Note I can only assure this works with how it is wired thru the front or #1 unit. I removed the front unit (13,500 BTU) to install the Houghton 3800 in it's place. I had to leave the control box in the plenum with only the 12 volt connector hooked to it an P1 &  P2 RJ11 (telephone Jacks). P4 needs to stay which is the temp sensor for the inside for zone 1. I have verified everything worked as before except the Houghton is a stand alone system with it's own remote control. If you want the number 1 furnace to work you will have to select it on the 5 button control board and set your required temperature in Zone 1. The Houghton does not interface with any dometic equipment. I cannot tell you anything about adding a new thermostat or connecting into the 2 blue wires etc... as talked about in other post.  I have my HVAC system working without adding or rewiring anything.

Good luck if you are doing the same thing and feel free to contact me if I can help or assist you. Thanks to Tom for helping me understand some of this better also. I did contact Dometic originally for help and they would not even give me the time of day. The Houghton is much quieter inside and outside. Parts are also available for them where they are not for dometic. Will follow up with decibel readouts when I get everything tidied up.

Kenneth Cox

402-319-3445 or klcdenver@gmail.com

Thanks. I do not have aqua hot but I should reconnect P4 as it goes to the indoor temp sensor. I am pretty sure it requires a 12 volt thermostat. Take a look at the attached wiring diagrams. Both diagrams show 12 volts to t stat. The plug with thermostat coming of my furnace is square Molex and not long like this diagram but I could not reach it without dissembling a lot of stuff to check voltage on it.

Thanks for the help guys. Oh yea I plugged the Houghton in prior to installing it and it is extremely quieter on the outside than my dometic penguin. In fact the penguin on the roof drowns out the Houghton on the ground standing beside it.

thermostsat.pdf

I Just finished getting done. I removed the front #1 Penguin 13,500 BTU. On the 13,500 the control box is in the plenum like Frank's picture shows. I removed all the AC wiring from the box. I also removed P3,P4&P5 connections from the box. My front furnace works as it should in furnace mode without adding a new thermostat. My rear unit #2 still works in heat pump, AC and furnace mode as it should.

Note: the newer Penguin's 15,000 BTU has the control panel mounted to the roof under the shroud. It will need a different route to get it to work.

Wrong again. See attached picture. P1 kills power to thermostat. P2 kills rear unit. Maybe this will help someone tell me what to do.