Thermistors

[jimshoen]

On my 97 Marathon there is a read out on the Marathon mounted dash display for temperatures. After selecting the correct screen page it displays outside temperature, storage bay temperature, and water bay temperature. Since I bought this coach none of the readings have been accurate. Leon at Marathon connected with the coach throught the Marathon TechLink and adjusted the readings based on three different thermometers I placed in each area. Unfortunately it did not work. The outside temp gauge is most crazy. After speaking with Leon again he recommends replacing the thermistors. Anyone have an opinion?

[JIM CHALOUPKA]

On my 97 Marathon there is a read out on the Marathon mounted dash display for temperatures. After selecting the correct screen page it displays outside temperature, storage bay temperature, and water bay temperature. Since I bought this coach none of the readings have been accurate. Leon at Marathon connected with the coach throught the Marathon TechLink and adjusted the readings based on three different thermometers I placed in each area. Unfortunately it did not work. The outside temp gauge is most crazy. After speaking with Leon again he recommends replacing the thermistors. Anyone have an opinion?

Jim, just from the fact that you are inquiring about the accuracy of the temp. readings,(it must bother you) you should pursue to see what the replacement of the Thermistors involves. I would: ask marathon how much they are and weather you can change them in the field, by you. Does it involve circuit board soldering or plug in exchange. You already know they can calibrate it for you. Get their pricing and compare it to others for the same job. Nick Hessler @ Omnitech. Ask him what he thinks about it! You could possibly get the parts and see if he would do the repair at Sevierville in the spring, or if you sent him the circuit board. His add is in Prevost-Stuff .
This is all if you don't want to tackle the job yourself. A Thermistor is a resistor used to measure temperature changes by measuring its resistance which changes relative to its temperature. The device would be equated to an ohm meter with the scale calibrated to read degrees. Thermistors are available as elements (look something like an led component with two leads for soldering to a board or cable) and as finished/complete assembled probes with cable. I will guess you have an assembled probe in each bay area. You could locate it and see who made it and then go to them for replacement parts, or try to find a generic replacement. They would then simply be wired into the control box the same as the old one is removed, probably screws to a terminal strip.
Sorry for my sequence, it's just the way it developed in my mind and went down without retyping. Hope this is what you are looking for
You are first with the topic so you could be the expert and keep us up on this one?

[Kevin Erion]

Jim,
on my 99 I had the outside air temp reading go way out of bounds, like 260 degrees. I changed the sensor behind the front bumper on the driver side and fixed the problem. if this sounds like something your's is doing, I would recommend the new sensor.

[Petervs]

Kevin,
You were just fooling yourself. haven't you heard of global warming? This is just the first indication to hit home, the outside temp is 260. Just by changing the thermistor will not solve the problem, buddy!

[Jon Wehrenberg]

Peter....Kevin solved the global warming problem by changing the bus. Now the temperature is more to his liking.

[lewpopp]

Kevin, my outside temp reading is off about 7 degrees. By changing the sensor can I correct that. Where do I get the sensor? How far back from the head do I go, etc, etc.

[Kevin Erion]

Lew, I am not sure with your's being so close and mine a little more out of wack. The sensor was mounted behind the front bumper and the wire ran thru the stainless and into the lower compartment with the steering box.
I did the wire connection there and it was very easy,

Jon,
I just made another temp go up with the new bus, mine. But I feel that at the end it will be well worth the extra work I took on. I just kind of want to see the end NOW! I remind myself to have patience, something I have a short supply of.

[jimshoen]

Called Marathon and they are sending me a new sensor for the OAT. Lady in parts said it will be no charge? Well, maybe the freight will be $40.00.

[wrongagain]

Kelly in parts has sent me hundreds and hundreds of dollars in parts and never asked for a dime, from warranty stuff, to stupid stuff, light bulbs etc.
even when I knew there should be a charge.
always shipped overnight.
marathon has stood behind its product 100%, so far.