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Onrecess · 08-11-2021, 08:40 AM

Kind of a shot in the dark here. I am stuck, stop engine light. The wrecker sent a mech who scanned it and said sensor beging coolant tank. I have a sign commander 525 isx, can someone possibly tell me if you can get to said sensor thru bedroom floor? I have been Watford a wrecker for 23 HOURS.

jacwjames · 08-11-2021, 08:57 AM

You have a rear radiator coach and should have a surge tank. You should be able to visibly see if the coolant is low. If it is not low and you have a low coolant alarm you should be able to bypass the sensor if you have a tank that looks like this
https://shop.findmyrvparts.com/searc...h=tank&Submit=
The original tank had a coolant sensor that went down from the top of the tank. It is known to get a build of stuff on it causing the low coolant alarm. you can pull the sensor and clean, it simply pulls out of a heavy rubber grommet.

Or if you know your coolant level is good you can unplug the sensor and put a ground wire to it and the alarm will go off. Monaco used a Kysor low coolant alarm that senses ground through the coolant.

I replaced my tank, the sensor moved to a location on the side and uses a Ford sensor.

zmotorsports · 08-11-2021, 08:59 AM

If it is the coolant level sensor it is located in the surge tank accessed through the rear engine hatch and easily located. If it is a coolant temperature sensor then that is located in the head of the engine and more than likely would have better access through the bedroom floor.

The mechanic stating coolant tank has me believing it is the coolant level sensor and not temperature sensor.

Outbound · 08-11-2021, 10:18 AM

Sounds like you may have a side radiator rv, your thread did not say, if so you should be able to visually see coolant level in engine compartment, if low that may be your problem.

vito.a · 08-11-2021, 10:34 AM

It is a 2003 Monaco Signature with a Cummins ISX 525. Side radiator and aluminum coolant over flow tank. The coolant level sensor screws into the tank from the rear and is easily accessed from the engine access door on the rear.

The level sensor will trigger a Check Engine but I doubt that would generate a Stop Engine.

More than likely its the coolant temp sensor in the cylinder head like Mike says.

Onrecess · 08-14-2021, 11:04 PM

Turns out, he was wrong. The fuel shutoff solenoid Is bad. That led to finding it was getting 5 volts. That led to the faulty ECM. Ouch! Sitting at Cummins Atlantic, waiting for the parts.