Where are my basement and outside temperature sensors?

[daveyjo]

I recently posted something about where are my Aladdin temperature sensors, and got some feedback but haven’t found them yet.  I traced the leads from the connection modules in the main basement storage compartment for a little ways, beyond which they were inaccessible.  The leads went over to a channel in the basement center, where they both seemed to head toward the front of the RV.  I used a wire tracer but the signal faded out as I got toward the front of the channel in the ceiling.  So I still don’t know where they ended up.  It looks like a lot of work to get inside the ceiling channel and trace the leads further.  At that point I decided maybe it would be easier just to put in some new sensors and route them where I please.  I assumed the system uses thermistors (resistors that change resistance with temperature) to sense the temperature, and I thought all I need is to find some new necessary thermistors.  That’s when my new problems started.  I measured the resistance of both sensors and found they were both either open circuits or the sensors were something other than thermistors.  So now I am stumped.  The ceiling mounted box where the sensor leads plug in maybe has power (it is a tiny pinhead sized light (no doubt an led) that blink quite rapidly but is barely bright enough to be seen, so I don’t know if it is a power issue or what else the issue is?  The Aladdin tank levels except propane don’t work (but show a number other than zero), so maybe the Aladdin system itself is broken rather than those tank sensors.  So, anyone have ideas about this??.

 

Dave Jones

2005 HR Scepter

[redstickbill]

Dave,

I believe the ambient temperature sensor is in the fuel compartment in my Dynasty.

Bill B 07 Dynasty

[daveyjo]

Thanks.  That makes good sense.  It is about removed as you can get from heat sources.  I'll look there.

Dave

[k7jv]

We had a second outdoor one mounted behind the nose, driver's side, down pretty low forward of the firewall for the outside when we had the Silverleaf replacement for the Aladdin installed.  The original was where "Bill B" said his was.  Originally, it was tie-wrapped to the front A/C drain hose as it ran down thru that compartment from the top of the drivers-side opening to below the coach.  (I took that loose on our coach and tie-wrapped it further down that drain hose so that it just did extend below the floor.  I felt that would give it a more true reading than further up in the compartment.  I don't know if it helped at al.). I think the "basement" one was mounted to the bottom of the floor (the ceiling) in the passenger side of the wet bay compartment.  I think.  You are looking for what looks like about a 2" long suppository (Ouch!!) on the end of that thermocouple cable.  If you find what you think might be one of them, try immersing it in ice water in a cup, or spray it for three or four seconds with "Brake Clean" or a spray electronics cleaner to really chill it and see if it responds on your display.

[daveyjo]

Wow, thanks everyone for the tips and pics for the outdoor sensor.  I'll check there the next time I get to the RV.  

Even if the sensor was a thermocouple instead of a thermistor, I should have measured some resistance so I am still stymied about what the sensor is.  This will really help if I can find the sensor.

Dave Jones

[daveyjo]

OK, thanks to all the clues from the forum, I found the outdoor temperature thermistor. Thank you, thank you, thank you.  It was in the fuel tank compartment but on the road side attached to the ceiling.  I unplugged the sensor- with its 1 foot lead - and measured continuity directly.  The resistance changed as I warmed it up, so the next question was why doesn't the Aladdin read any temperature?  I bypassed the interconnection wiring and connected it directly to the Aladdin connector box on the ceiling of the slide out storage bay and it worked fine - plugged into either the outdoor temp connection OR the basement temperature connector, so it appears the Aladdin electronic system is not why I have been gettin -31 degrees as my temperature readings.  Clearly it is that the connection between the outdoor sensor/thermistor and Aladdin connector box is broken, and appears is the same problem for my basement temperature sensor.  So, maybe two broken wires is my problem?? So now my challenge is to either run a new wire or decide if just the connectors are bad.  

Now that I suspect a broken wire for the basement sensor, my challenge is now to find the thermistor for the basement/water compartment. Both 2 wire leads go to a tunnel of sorts in the ceiling of the basement and I couldn't trace them any further.  So, if anyone has a clue as to where the basement temp sensor is, I'd love to hear it.  (I'm guessing it is in the sewer bay behind the shield in some place almost impossible to get at.)😉

Also, does anyone have a clue about finding a replacement thermistor in case I can't find the basement sensor?

Thanks for all the help.

Best regards, Dave Jones

2005 HR Scepter

Edited November 8, 2020 by daveyjo

[granvillebarker]

Dave, 

I am fairly sure my basement temp sensor is on the end of a coil of wire near the Aladdin box that it connects to, in the top of the middle storage bay.   I’ll look tomorrow and get pics, there should be a number on the sensor itself.

 

—

Granville Barker

05 Dynasty