Anyone know where I can get a used, or have someone rebuild, my Dash SCS HVAC circuit board? 2001 Dynasty

[Bill C]

Anyone know where I can get the Servo control board for the dash heat and air conditioning in a 2001 Monaco Dynasty? Apparently it turns the engine hot water valve off to the unit when the air conditioner is running. When it fails, you get hot and cold at the same time and that’s not a good combination if you want cold air. I posted about this before but I wanted to see if somebody knows somebody that rebuilds circuit boards. 

Where can I find a used one?

Attached are some pics of it.

Thanks,

Bill

[Tom Cherry]

29 minutes ago, Bill C said:

Anyone know where I can get the Servo control board for the dash heat and air conditioning in a 2001 Monaco Dynasty? Apparently it turns the engine hot water valve off to the unit when the air conditioner is running. When it fails, you get hot and cold at the same time and that’s not a good combination if you want cold air. I posted about this before but I wanted to see if somebody knows somebody that rebuilds circuit boards. 

Where can I find a used one?

Attached are some pics of it.

Thanks,

Bill

Have you googled PDXRVWHOLESALE.com?  They list parts for the SCS HVAC UNITS

 

[hex_nut]

Many years ago, I was in need of one of these.  There were none available anywhere (just like now).  I took a walk in the back lot of Colaw's RV salvage and retrieved a couple of used ones from wrecked RVs.  You might try the salvage yards, but I suspect any usable ones have long since been retrieved.  I have known others who have replaced the servo motor valve with a mechanical one.  A friend of mine adapted a cable actuated valve so he could still control it from the dash controls.  I saw another that was just a lever actuated valve, but it would be darned inconvenient to have to stop, go out front and turn the lever when you wanted to change from heat to air conditioning.  Another friend replaced his with a later module unit that had the control board built into the control valve rather than being in the wiring harness.  The bad part was he had to replace the dash control and wiring harness out to the valve.  He removed all those parts from a wrecked unit in a salvage yard.  This is a sticky situation to be in and there is not a nice solution if you cannot find a working control board.  Good luck.

Richard 

[jacwjames]

Try messaging or calling Visione RV in KY.  https://secure12.makatary.com/cgi-bin/en.visonerv.com/e-mailmessageform.pl?

Give them as much info as possible about what it is, where it is located, Make/model/year of rig. 

When I was there last Oct I asked the salesman if they list everything on the website, he said no that they just had too much to list.  But advised me to contact them and they would look. 

[Tom Cherry]

@Frank McElroy PM Him.

If the three chips are standard and NOT programmed, he is a whiz at troubleshooting boards.  This is not a complex board….

or perhaps @pwhittle.

These guys can fix the Intellitec boards for the Dynasties….

All they can say is NO.

Also contact Dinosaur Board.  They do a lot of refurbishment…..

Have you called NorthWest RV Supply and asked them?

[pwhittle]

The IC’s are still available. I expect the regulator is too.

Should be a fairly straightforward return on that board.

paul

[cbr046]

10 hours ago, pwhittle said:

The IC’s are still available. I expect the regulator is too.

@pwhittle You might stock up on the MC33030P controller IC.  I only checked a few places and everyone was out of stock . . . except ebay and those pirates are asking $30 - $40 for a single IC!  😮 

Still better than scrapping and starting over . . . but geesh!

- bob

[pwhittle]

Yep, but may be the best alternative.

Paul 

[Bill C]

10 hours ago, cbr046 said:

@pwhittle You might stock up on the MC33030P controller IC.  I only checked a few places and everyone was out of stock . . . except ebay and those pirates are asking $30 - $40 for a single IC!  😮 

Still better than scrapping and starting over . . . but geesh!

- bob

Good Day pwhittle,

I have two numbers on the chip, does a replacement IC chip have to match both numbers?

What do the numbers mean?

Here are the 2 numbers on one IC chip: MC33030P and CPJQ9934

Thanks,

Bill

[cbr046]

The latter looks like a xxx batch or plant ID with 9934 date code.  MC33030P is the important number.  "P" is the type of package - DIP or dual inline package.  A different last letter might work with modified last resort kluge wiring.

- bob

Edited April 26, 2024 by cbr046
incorrect autocorrect - online vs inline

[Bill C]

Hi Bob, thanks for the info. I am considering "easter egging" the parts on this control board.

In which order would you try replacing the components?

I'm attaching a pic of the board for reference.

Any help would be most appreciated.

Thanks,

Bill

[Ivan K]

Just curious,  are you certain the problem isn't on the valve side?

[pwhittle]

What are your symptoms?

Paul

[cbr046]

9 hours ago, Bill C said:

In which order would you try replacing the components?

I'd start with the cheapest and work up from there, or shotgun all 3.  Be sure to use a good soldering station and static precautions.  A 100W Weller gun is not your friend.

- bob

[Tom Cherry]

I ain’t no tech…but I did frequent the “Weller” plant as it was in my division and I had responsibilities for many functions there.  Got to know the designers.  A Weller low wattage soldering station is your friend.  They kept giving me the newest model to use at home and critique.

I’d start with the Capacitors…..they die first. I fixed more “DEAD” LED TV’s than I can remember buy using an eBay kit and replacing all of them.  DEWICKING mesh is your friend….  Then check the resistors….but typically they will “tell” you.

Good Luck.  If you fix it…write it up….pictures and such.  We’ll put in the files,…

 

[RoadTripper2084]

12 hours ago, Bill C said:

Hi Bob, thanks for the info. I am considering "easter egging" the parts on this control board.

In which order would you try replacing the components?

I'm attaching a pic of the board for reference.

Any help would be most appreciated.

Thanks,

Bill

I'd start with the capacitors, diode, and transistors. Resistors don't usually fail and when they do they tend to be burned up in appearance. 

Edited April 26, 2024 by RoadTripper2084

[Bill C]

15 hours ago, Ivan K said:

Just curious,  are you certain the problem isn't on the valve side?

Hi Ivan, yes I have actually replaced the valve, externally plugging a new one in, and same issue.

[Bill C]

16 hours ago, pwhittle said:

What are your symptoms?

Paul

I have Dash Heat in ALL settings, including A/C and Max A/C.

[Tom Cherry]

2 hours ago, Bill C said:

I have Dash Heat in ALL settings, including A/C and Max A/C.

I am NOT an expert...but many folks at our gathering are well informed and have worked on their systems.  The way that the systems are "SUPPOSED" to work...  and getting adequate heat is the common complaint....

When you want MAX HEAT, you turn the control to MAX AC.  You rotate the temperature Valve to MAX HEAT.  That activates or causes the control on the water valve to close the valve.  

We recently had a Valve issue and the member contacted the system vendor and found out that the controller was bad.  There was a plastic gear inside and the teeth were stripped.  It was FINE in the heat zone....but would NOT turn off.  It actually made a clicking sound and you could hear the controller cycling....trying to complete the FULLY OFF command.

You MIGHT have someone slowly rotate the COOLING or Temp knob and make sure that the heater control valve is functioning.  

I know this works this way....as I complained for years...but then knowledgeable folks explained it and BINGO...I have have great heat in the colder temps while driving.

Here is a link to the recent threads. They  might give you some insight... You can use a key word or word....like Heater or Heater Valve or Hot Water Control.  THEN click on EVERYWHERE and choose TOPICS.  That will give you a list of all the posts....you then skim and start reading and focusing on the ones that address or discuss your problem...

 

 

[cbr046]

2 hours ago, Tom Cherry said:

When you want MAX HEAT, you turn the control to MAX AC.  You rotate the temperature Valve to MAX HEAT.  That activates or causes the control on the water valve to close the valve. 

Yes, works better than the other positions (floor, dash, etc) but when I did this my compressor locked up.  Pretty sure it was coincidental . . .

- bob