[Wanderman]

Yup
I spoke with newell and ordered a thermostat. Not sure what i am getting, likely a 2 stage one, but it looks like it MAY be an SCS one(!) We shall see. Also, on another topic, I ordered the Aquahot DPST limit thermostat that is going for ~500 USD from them for under 400...such a deal!

[Richard]

Ok, it would still be good data to take your voltmeter and measure the outputs of GL, GH, and Y1 when the tstat is set to cool and the setpoint is below ambient.

To test your premise about incorrect wiring, let’s run another experiment. Make a short jumper wire, and jump Red to GL. The inside fan should come on. Does it? Then jump Red to GH, the inside fan should come on, at a slightly higher speed. Does it? Then jump Red to Y1, the outside fan and the compressor should come on? Does it?

If that works, then do this. Kill the breaker for the unit. Install temporary jumpers between GH and RED, and a temporary jumper between RED and Y!. This will simulate the Tstat telling the control board to run the unit. When the temp jumpers are installed, turn the breaker back on. Now you can measure the amperage and cooling temperature.

Caution, do not run the unit for more than 30 seconds with just Y1 jumped because the indoor fan will not be operating and the compressor will soon trip on high amperage.

I have internet connection today and Saturday, then I am back in the woods all next week.

I am ALWAYS hesitant to answer the question, what color wire did Newell use because no two Newells are alike. Newell may have changed their color scheme. A PO may have changed the wiring. My approach is more to use my voltmeter and figure out the color scheme. You will discover that just outside the basement unit that the standard multicolor tstat wire that you see at the tstat is spliced into a pigtail supplied by SCS. So it really doesn’t matter which color is used, what matters is the signal going to the control board.

The next step IF the jumper simulation doesn’t wake the basement unit up requires that you gain access to the control board in the basement unit.

This tstat will work for single stage AC and also run the Aquahot. https://www.amazon.com/Coleman-Airxcel-8...32&sr=8-12

And the wiring that I previously outlined. https://www.google.com/search?q=coleman+...0YhrtslKmM



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[Wanderman]

Did a bit of work on the HVAC single 1301 unit and thermostat today using Richard's excellent troubleshooting/testing guide.

After confirming POWER (RED) and GROUND at the t-stat this is what I found:

1. The PSG thermostat is intermittent, the slider switches aren't working well. It could be cleaned, but unknown at this point. I have a new thermostat on the way.

2. Jumping the fan GL to RED I get a click from the AC bay.

3. Jumping the fan GH to RED I get a click from the AC bay.

4. Jumping the compressor/fan Y1 to RED I get Nothing at all.

Tomorrow I will find the access to the AC panel itself and confirm I have 120v power at the box and at the control panel. Who know, maybe there are some wires or plugs disconnected. I know the PO was messing with it.

Hope the control panel is not toasted nor unrepairable. Newell did tell me they have boards available, but....it's Newell so at what cost.. Though the AH DPST 240V/120V Limit thermostat the sold me was the least expensive of anyplace so who knows.

Thanks to Richard for walking me through this.

[Richard]

The click is the sound of a relay in the board kicking in. The relays on the board are 12 VDC.

Sounds like no power on the board. I agree with you that the next step is measuring input AC voltage to the board. If the board is toast, the newell board is circa 700$. Read @"bikestuff" recent thread on fried board.

[Richard]

Rick,

Not trying to be a wise guy, but sometime during the night the thought that your work on the Aquahot electrical side and the AC not having power have a common denominator. Most Newells of that vintage have a switch above the Microwave that allows you to EITHER power the electric side or the AC units. Many of us have forgotten about that switch when the AC’s don’t come on.

Just checking all the possibilities.

[Wanderman]

Richard,
Yup, I am aware of the Aquahot switch for electric ops. It's in the correct position. And the rear dual compressor unit works fine.

Good idea though.. I have done some boneheaded moves like that in the past!

[Wanderman]

Here's the latest.

Spent about an hour disassembling the side of the AC only to find out that the control panel is only accessible from underneath! Put THAT all back together Put some jack stands on the coach and and managed to get the tight fitting control panel cover off. At least i can easily sit up inside the area the AC unit is in. 

Here's what I found out. Unlike the rear dual compressor unit, this one appears untouched. No external relays at all.
I'm attaching some photos of the board ans access panel schematic sticker if anyone has a single unit and needs them.

With the power off to the AC unit checked at the source and at the board (BTW the labels on the House AC panel are wrong...) I wiggled the wires around a bit. Repowering the system now gets me 12V relay sounds for all RED to GL, RED to GH and RED to Y1. Though no fans nor compressors. Next i will test if 120V is running into the board. I do have it at the wires leading in to the board but haven't checked at the connectors.

Being methodical is always best. One step at a time.

More as I learn about it.

[Richard]

Oh boy! That is a board unique to the single compressor units. IF you need a new board, the newell board will work, but you will only use half of it. Take a really close look at the compressor connecton, the neutral wire looks like it has been really hot. The original boards have several weaknesses. One is the soldered connection for power in; one is the lands on the back of the board are inadequately sized to carry the current; one is the inadequately sized connector for the compressor and fan motors.

I would pull the board at this point for inspection of the back side. The fixes may be simple if you are handy with a soldering iron.

If the board is totally cooked, there are some “options” other than the Newell board if you are comfortable with basic electronics.

In any case, while i am in there, all the start caps should be replaced

[Wanderman]

Richard,
yup.. as usual I'm the oddball. I should be used to it by now. Removing the board is likely a good idea. It's not obvious how it is attached to the chassis. Sort of looks like a nylon standoff on the lower left with a bit of hot melt glue... but not 100% sure. Usually there are some screws or some such.

I agree the it definitely appears that some overheating has occurred at some point. The smaller cap looks really bad, the other may be of a newer vintage. Anyway it's now raining again so not going to fool with it any more today.

Perhaps before I remove the board, I will have someone switch the relays at the thermostat leads (or create a jumper set at the board) and see if any 120v is passing when the relays are closed.

No problem using a soldering iron, I've don trace fixing and the like. Even component level replacement is OK.

I wonder if there isn't a simple AC control board that would just work instead of the factory one installed here. I mean, it's a simple AC unit, right?

We shall see what develops.

Thanks!

[Richard]

The problem with using any commercially avail board is they will be 24 VAC, not 12 VDC.

The standoffs are likely plastic. If you can get some long nose needle nose pliers in there to squeeze the tabs it will pop right out.

If you said this, I missed it. Is 120 VAC confirmed coming into the board?

If you have 120 coming into the board and want to test what is working and what is not then do this.

Unplug the connectors for both fan motors, they will be three wire. Unplug the compressor connector, the two wire.

Put the jumpers in place at the thermostat. Turn the 120 power on. Use the voltmeter probes and test for voltage at the connectors on the board.

Jumpers at the board will be way too finicky where the control wires come into the board.

If you take the board out, all of this can be tested on the bench with continuity between the incoming voltage connections and the outgoing connectors for fans and compressor.