98 t-26c a/c issue

[JDSunline]

I have a saturn t-26c with a brisk air by duo therm. the compressor kicks on however i cannot get the blower/condenser fan to work. I have spun it manually it turns freely and i have turned it on and spun it and it does not continue to run.(a trick i have read about online) Does anyone have any further ideas/tests i can try? Any input would be greatly appreciated. Thank you.

[JohnB]

Hi JD,

I do not know on your exact model, so I will give some general answers. So we can help you better can you get the model and serial number of the AC unit and post? Also what model and year camper do you have? We can look up which vintage you have along with the wiring diagram. Here goes some thoughts on this.

You did some good troubleshooting already. We know the compressor runs and we know the motor is not froze up. This is a good start.

When was the last time (in days, weeks, months or years) did it last work?

Does yours have a 2 speed fan? Did you try running just the fan on the other speed? Trying to see if both speeds are dead or just one.

How handy with electrical and electronics are you? Do you have a VOM meter? Volt/Ohm meter. And while most of the VOM’s today are digital do you have an older analog one as well? We can use the old analog one to test the starting capacitor of the fan.

If the 2 speed trick does not start on either speed, you are about into an electrical trouble shooting mission.

Have to define if the starting capacitor is any good, is the control board sending a run speed signal and is the motor itself not shorted out. Or you have a loose wire somewhere and it is that simple. Since the compressor runs when the T stat is calling for cooling, we know a lot. The control board is partly working, the T stat is working just the fan itself is not starting. That is a big step.

In order to do the tests that I now of you need to be electrically friendly short of looking for a loose wire. Do not want you accidently getting hurt trouble shooting this. Some tests are without power, some may be to hot wire the motor. My knowledge is on the newer ducted air units but the non ducted ones should be close to the same. These AC units are very basic in control scheme.

Hope this helps

John

[JDSunline]

Im in mass and the trailer is in New hampshire right now so a model number will be tough however it is a two speed fan and both speeds are inop. Its a sunline saturn t-26c. I purchased it this year and have had this problem from the first time i hooked it up. I am an auto mechanic so 12v circuits are very familiar however 110v circuits are not, But i dont mind trying a few things and i know enough about the electrical to not injure myself, i.e capacitor storage/discharge and hot/neutral/ground wires. i have a digital voltmeter. It is a ducted 2 speed system. and if you could point me in the direction of a wiring diagram that would be awesome. Thank you for the fast reply.

[JohnB]

JD,

Do you know the year of your camper? This sort of gets me closer to what you "might" have.

Thanks

John

PS, Does the 98 in your subject stand for 1998? If so then yours is not that old and may be just like mine which I have many pics of.

[JDSunline]

yes 1998, sorry.

[JohnB]

Hi JD,

I'm running out of time tonight. Will post a bunch of pictures tomorrow on one of my units as I trouble shot the unit.

In the mean time this will either help or bury you.... I hope it helps.

Go here for motors.
Northwest RV Supply

Scroll down to Duotherm. Select "Air Conditioning and Heat Pump Service Manual"

http://www.nwrvsupply.com/manuals/du...at_service.pdf

Pages numbered at the bottom 27 to 30 are on motors.

I have pics of the control board where you can test the fan low and high speed relays to tell the board is OK. See page 39 in the manual where you use a test light bulb to check the PC board.

And you can hot wire the motor to try and run from the board area. If it does not run hot wired then the problem is up top on the roof unit. Odds are high it is in the start capacitor. And I have pics of that too.

In the Motor section it shows how to use an analog ohm meter to test the capacitor.

A wiring diagram shows up on page 58 for the roof top unit.

Be back on Friday. I may have another Duo-therm manual too. Have to look some more.

John

[Sunline Fan]

John, a Saturn 26C is identical to a Solaris 2670 if that helps at all...

[JohnB]

JD,

Forgot I had these up on my photo server already from a T stat upgrade.

When you pull off the plastic grate inside where the foam filter is, above this area is the AC control board behind the sheet metal cover.



And the wiring diagram of the roof unit is here. The plug that is white on the bottom left in the pic above with the black sleeve over the wire bundle goes up to the roof unit. That plug shows up in the lower right of the diagram showing the fan motor Hi and Lo wires along with the compressor blue run wire.

- When the black wire is hot the fan runs hi

- When the red wire is hit the fan runs low.

- The big blue one is for the compressor. When hot the compressor runs

- The white is the AC commom.

- The green yellow is earth ground.

Those are the only wires that go from the control board up to the roof unit. There are more interconnections in the capacitor box up on the roof.

All the other wires hanging out with the wire nuts on them are T stat interconnections, 12 DC +, 12VDC -, the furnace interlock and the freeze control sensor. Those should all be working if the compressor is running.


More to come later tonight

John

[JohnB]

Originally Posted by Sunline Fan

John, a Saturn 26C is identical to a Solaris 2670 if that helps at all...

Jon, thanks. That does help.

Since this is a 1998 unit and JD says it has ducted air, and the camper inside looks like what is on a T2670, odds are high this is the same 13,500 BTU AC unit that was on my 2004 T2499. And even my 15,000 BTU unit on the T-310SR I have now. I have a lot of info on those 2 units.

I do not recall Dometic doing any really large upgrades on the units between 98 and 2004. Or even up through the last 2007 Sunlines for that matter.

I must say, one sure learns a whole lot more when things do not work right then when they do... this is one of those cases.

[JDSunline]

Thanks for the input guys. I am heading up on saturday and i will try to jump the motor quickly and see what happens and go from there. I will post my findings. Thanks again.

[JohnB]

I'll post some pic's yet tonight. Hunt up a 120 volt test light of some kind. Even a shop light and some aligator clips to attach to the plug. Do not need any more then a 25 to 60 watt light bulb. You can test the relay board with the clip light.

Check the forum in the AM before you head out. It may take me until late tonight to get the pics up

Here is 2 of them I had up from long ago.

You can take the cover off the control box to get acces to the board. The wires just have push on terminals. Easy to unhook and test/jump. I'll get closer pics so yoiu can read the words on the board.





John

[JohnB]

Hi JD,

Here are some more pics to go along with the manual.

I myself would start trouble shooting what you are describing of having the compressor run but no fan in this order. You need to take all the electrical wiring precautions to do these tests. If you do not feel up to them, stop. You are proceeding at your own risk. OK now past that here goes.

Take the inside plastic intake cover off that has the foam filter in it. Above this is a metal electrical enclosure with a small lid. Turn the 120 VAC breaker off to the AC unit. It should be a 20 amp in your breaker box.

The control board also uses 12 VDC from the battery. Unhook the battery or pull the fuse if you can find the right one. Now that box should be is totally dead. Test for voltage as needed.

Take the metal cover off. Odds are high just that little cover you are not going to see much other then the 3 amp fuse and a part of the board. Looks like this



So I took the entire shroud off and unscrewed the box to hang out so I can work on it. Now looks like this




Here is a close up of the board itself


Here is the wiring diagram on the board


You now have 2 options of what to check 1st. The relays that turn on the fan or the fan itself.

I'm going to just start with the fan relay on the board. Get a 120 VAC test light. Any kind of light bulb with a cord etc. A shop light, even and old lamp. Do not need much more then a 25 to 60 watt light bulb.

You will need test leads with alligator clips on the end OR strip the wires on the lamp cord etc.

Unplug the fan lo (red) and the fan hi (black) wires off the board. Let them hang and make sure they do not touch anything. Tape if needed.

Look for the white AC neutral coming in on the piece or romex wire. Put 1 lead of the 120 VAC test light on the common. Then using an alligator clip put the other lead of the test light on the Hi or the Lo spade on the control board. Make sure no hot wire is touching ground etc.

Turn on the 12 volt battery, then flip on the 120 AC breaker. Turn on the T stat so the unit will run. The compressor should start as you said it already did. The light should turn on for what ever hi or lo relay you clipped to. Try the fan lo/hi switch on the T stat. The light should go on and off with that switch.

If the light works, then you have a fan motor problem. If the light does not work, then you have a fan relay problem or the control board running the relay.

I'm going to assume the board worked and the light came on. This means you have a problem with the fan up on the roof unit.

Before you tear into the roof unit if you want to try and jumper the motor to run here is one method.

Turn off the 120 AC breaker to the unit. Unplug the hi and or lo fan wire on the board. With a alligator jumper, jump the hot 120 VAC incoming black wire, I used the black wire on the compressor relay as it was easier then taking off the wire nuts. Then jump direct to the hanging red hi fan wire. Like this


When you turn on the breaker, it will allow 120 VAC to go right to the fan motor. If it does not run, then there for sure is a problem on the roof unit.

OK now up to the roof unit. Take the big shroud off. You said you spun the motor so you where this far already. Turn the 120 AC breaker off so there is no power.

Looks like this


On front right side is the capacitor box. You can see it here. There is also a wiring diag on the cover.






And a warning label as they are capacitors inside


Inside is the compressor and the fan motor start capacitors




Here is the compressor one I was testing with my old analog meter


It broke loose inside. Maybe vibration etc.


Here is the fan start capacitor




In the pics one is silver and the other was white. I have/had 2 campers and the fan start capacitor was different. If you have an analog meter you can test them. Follow the Dometic manual.

There should also be an ohm check in the manual for a dead motor or at least an open winding. Your digital ohm meter can check for an open winding.

Odds are high it may be a capacitor, a loose wire. Last resort is the motor itself. The motor is like $130 to $165 IIRC. I bought one about 2 years ago. Bigger problem with the motor is you need to tear 90% of the roof unit apart to put the motor in. Have pics of that too.

Write down all the model and serial numbers of the AC unit. There are inside up by that control box. You can buy all the parts on line if you have no dealer nearby. PPL Motorhomes web site has an exploded parts diagram you can buy most any part. I have bought some from them.

Good luck, take pics so you remember and need to ask more questions and we can see what you are up against.

Hope this helps and stay cool... Suppose to be 104 F here on Saturday. Man, it is hot out...

John

[JDSunline]

Hey guys, I managed to do some testing this weekend. I probed for power coming from the relay board to the low fan wire(red). There was only 4.5 VAC. which leads me to believe that the relay board has an issue and when i jumped the low fan (red wire) to the input on he compressor relay the fan still did not kick on. i have ordered both capacitors for the motor and compressor because i managed to find them both for $14. next weekend i will replace them and see if i can at least jump the motor then.

[EMD_Driver]

If you need a control box to help with diagnostics, I have an extra one.

Let me know...



.

[JohnB]

Hi JD,

Well good. Your on the right track.

If you need new parts, here is one place I have bought from. The control board, a fan and capacitor.

RV Air Conditioner Parts for Sale - PPL Motor Homes

Go to the online catalog, in the search category box, select AC units, find your make and model and they have exploded diagrams.

Keep us posted

John