Cruiseair Solenoid Coil question

[Sailor John]

Good day all,
I have been trying to diagnose the non-functioning heat side of my Crusiair 16K AC. (The cold side works well). This is the AC unit that serves the main salon. It is not going into heat mode when the thermostat is turned to heat. No click, no whoosh, nothing. After some beneficial research through this web site, I was able (gratefully) to ascertain that my coil (that makes the solenoid work) may not be functioning. When powered up in heat mode, it does not cause the solenoid to move and there is no electric current creating a magnet in the coil. I traced and checked all the wires and everything seems to be fine.
My question is, does anyone know where I can get a replacement coil? I have attached a picture with the relevant details stamped on the coil bracket.
As always, I appreciate any suggestions.
Thank you all,
Sailor John

 

[KPTIM]

Hi John,
You need to make sure the coil is good or bad for sure bad. The first check is to measure the resistance of the coil winding. Disconnect it from system and use an ohm meter it will read almost a short (just a couple of ohms) if it's good and of course it will read an open circuit if it's bad. Do not try to power the coil up if it is not on the valve (it needs the metal slug in the valve to keep the inductance right) or it will burn up.

It is possible that the heat side of the thermostat is bad. In this case the AC cool will still work. On the older Cruiseair thermostats there is a dead band between heat and cool desired setting.

Of course the refrigeration transfer/reversing valve can be stuck (the internal plunger that the coil moves). If that is the case you will have to make a decision about how much money to put in an older system to replace the valve or the entire compressor/condenser unit.

I may have one at the house if your coil is bad and you can't get it from Cruiseair.

Post more or send me a PM

Tim

 

[Reefgeorge]

Re: Cruiseair Solenoid Coil questioning

Measure the behavior at the leads going to the coil when there is a call for heat to see if the system is trying to move the valve. Also on my system you hear a click right before the compressor starts for cooling which is the reversing valve equalizing the pressures before the compressor starts. I am not sure if those older units start that way.

 

[Sailor John]

Hello again. I really do appreciate the assistance!
I did the ohms test on the coil this evening. It showed .18 . So it's not open, but I don't know what it should read. Next, with the compressor running and the thermostat in heat mode, I tested the 2 wires that go to the coil. There was no power showing.
So....
Now I am wondering, might the T-stat be faulty? Is there a way to 'short' or trick the T-stat into heat mode?
I have enclosed a few more pics: The first shows the ohms test,, the 2nd shows the line test to the coil, and the 3rd shows the top of the T-stat, removed from the wall, but not disconnected. (I noted a very small diameter 'pipe' running from it).
Again, your help is truly appreciated!
Sailor John

 

[Reefgeorge]

Is there a change in the voltage at the coil leads between call for cooling and cal for heat? I don't know off hand which position is energized.

 

[Sailor John]

Hello Tim and George (and everyone else too),
My understanding is that the reversing valve is energized in heat mode.
When I put the t-stat into heat mode, there is no action or sound at the reversing valve or solenoid. Nothing vibrates, clicks whooshes etc. (For reference, the other Cruisair unit has definite action taking place. Sort of a Click—Whoosh---Click, then the heat just pours out)
When I tested the leads to the coil in heat mode, there was no sign of power. (See pic #2 in last post). Yet, the coil seems fine through the ohms test (Pic 1).
Is it possible to put power directly to the coil leads to see what happens? Will I damage anything?
Certainly appreciate the help,
Sailor John

 

[Reefgeorge]

I would measure what the coil leads show in both heat and cooling mode and compare those two results to your known good unit. Another option is to swap T stats. Lastly, you can measure the coil resistance of the known good unit as a reference.

 

[Sailor John]

It is a good idea, in fact a great idea. But...I am 6'3 and 250lbs, and access to the units very limited in my engine room. However, I will try again. The thermostats are easy to get at, but they have what looks like that copper line going to them. I am afraid of breaking that.
Do you think I can try to energize the coil by a direct contact?

 

[Reefgeorge]

I would not try to energize the coil directly. That resistance reading would produce 60 amps at 12V (unless thats 0.18 kohms which is 180 ohms, I cant read the scale on the meter), more current if the voltage is higher so either the coil is energized at a lower voltage and/or there is some series resistance in that circuit or its defective. That's why comparisons with the other side would have been good to have. The coil resistance on a typical 24v residential reversing valve is tens of ohms so they would draw a few amps or less.

 

[Sailor John]

So here is an update:
I put the coil back on and double checked the incoming voltage in heat mode. Zero voltage.
I then took the bull by the horns and wired the coil directly to ac and plugged it in. Presto!!
Click-whoosh-click! The reversing valve kicked in and I have heat!! Now I need to determine why there is no power in heat mode.
Reverse valve, solenoid, and coil all work. Of course I bypassed the thermostat so the heat is either on or off. The quest for the fix continues.

 

[Boatsb]

You just said the thermostat is not sending the voltage . Either it's not getting power, it's bad or the wire to the reversing valve is.

 

[SKYCHENEY]

Nice job trouble shooting. I would get rid of that old thermostat and put in a Coastal Climate Control FX1. You will love it.

http://www.coastalcoolaids.com/allproducts/fx1aircondcontrol.html

 

[Sailor John]

Sorry George,
I appreciate your last post, but it looks like our posts were published very close to each other and I didn't see your caution note. I was updating on my phone which is harder to do.
So you know, I took my cue (to try the direct wire) from the info on the coil itself that said 120 V. It seemed to work. Electricity is not my forte. (Come to think of it, I don't know what my forte is...)
While I was able to hot wire it, I still need to figure out why the proper electrical wires to the coil are not energized in heat mode.
I am assuming that they take their direction from the t-stat. Do you think installing a digital control would be a better bet than trying to troubleshoot/fix the old 3 knob unit that is there?
With thanks,
John

 

[Sailor John]

Sky Cheney, thanks for the tip re thermostat.
Sailor John

 

[SKYCHENEY]

Sky Cheney, thanks for the tip re thermostat.
Sailor John

They are pretty inexpensive and easy to install.

 

[Sailor John]

Curious, does anyone have a Cruisaire 3 knob wiring diagram for the thermostat?
I am checking connections and it would really help.
Sorry to be a pest, but with your help I am making headway!
Thanks all,
Sailor John

 

[Sailor John]

Final update:
I found my problem! A wire leading from the back of the thermostat had cracked, and was being held in place by a piece of it's insulation. At a glance it looked fine, but after digging a bit, the problem was obvious. I simply replaced the spade connector at the end and problem solved. I have an operational thermostat, and I have heat now for the remainder of the season.
It's all good.
My thanks to everyone that helped me troubleshoot this. This is a great forum!
Sailor John