Coolant Expansion Tank

[Russell Dale]

I just replaced my coolant expansion tank with the nylon replacement from Allied Recreation Group. Had to order low coolant sensor and a wiring harness along with it as the location of the sensor has changed. Problem is the replacement sensor and harness have 2 wires and the sensor that I am replacing had only 1. Any ideas on how to wire this or is it the wrong part?

thanks,

Russell
20013 Beaver Santiam
Cummins 330 ISC

[Edward Buker]

Russell,

Was the old tank metal?

later Ed

[Russell Dale]

No Ed, it was plastic and had developed a leak. The old sensor was on top, one wire, and a long probe (10 to 12 inches). The sensor and harness sent with the replacement tank were both Ford OEM parts. Tank was a good fit.

thanks

[Edward Buker]

If it was a metal tank the frame/thread of the sensor was a ground connection. I think you need to get with the sensor and tank provider and see how they intended the replacement to work. It is not straight forward as to how the new arrangement should be wired.

Later Ed

[Russell Dale]

thanks Ed

[Steve Huber Co-Admin]

Russell,
If you coach wasn't a late Navistar build, Allied Rec Group would be the builder. They should be able to tell you how to wire the tank sensor up as they also sold you the new tank.
Steve

[Russell Dale]

Thank you Steve. I will contact them next week and post when I get an answer.

Happy Holidays

[Dave Atherton]

Russell, just had this problem about a week ago and could get only a 2 wire connection for sensor.
I can point you in the right direction where you can get a 2 wire sensor. The sensor and circuit board
is made by Medallion Corp, and if you use control module number ( KYS 1539  10208  03 ) and tell them
you need 2 wire sensor for top surge tank. Note: this part of the 5 volt sensor group that will derate engine
power to 1100 rpm. Can get this part through Freighliner.  Dave Atherton Retired Cat Mechanic

[Russell Dale]

Dave, great information. I have the 2 wire sensor and a short 6 inch wiring harness that plugs into it from the tank. I would assume that if a replace the Module that I would have to have another wiring harness to run from this tank harness to the location of the KYS 1539 10206 03 module. My inclination now is to tap the top of the new tank and use the old sensor and single wire. That sensor was fitted onto the tank with just a rubber grommet held in place and sealed by the sensor itself. I haven't compared the thickness of the 2 different tanks but they are exact in size and shape.  Any thoughts? BTW, if I went this route, the new sensor would just become a $150 plug for the bottom hole in the tank.

Russell
2003 Beaver Santiam
330 Cummins

[Dave Atherton]

Russell, this is correct. On your post middle row of numbers the last number ( 6 ) is correct for
2 wire sensor. On my post in same row of numbers my last number was ( 8 ) which I typed in
incorrect. Ahead what fails on this low coolant level sensor is the circuit board, which cost $ 37.00.
Problem when happens your engine will go into derate mode and stay there untill problem is repaired
of which means a new circuit board. I picked this problem up with my Cummins Insite Computer.
Dave Atherton Retired Cat Mechanic

[Dave Atherton]

Russell, stopped short on my thoughts. If the number you posted was the box that encloses the
coolant level control module, and you have a new coolant level 2 wire sensor that plugs into new tank.
if this is correct everything will work. My suggestion I would go with the 2 wire sensor with the plastic
tank. Dave Atherton Retired Cat Mechanic

[Dave Atherton]

Russell, looking at your old wire harness and your new wire harness and the 2 wire
connector. Looking at coolant control module box on new wire harness note: letter
( E - Probe Gnd ), than the letter ( B - Probe ) this is going to your 2 wire sensor. The
remaining letters go to coolant control module circuit board and ECM. Going with plastic
tank the ground has been removed as Ed had indicated. Just a thought you might want
To connect jumper wire and ground probe Via. Threads on connector. If this is correct your
Low coolant level light will go off on dash with the one wire sensor.
Dave Atherton Retired Cat Mechanic

[Dave Atherton]

Russell, being the 1 wire probe is on its way out, my suggestion is to update to the 2 wire
Sensor. You can double check both new connectors the way wires come off coolant sensor module.
2 wire to sensor for tank, Letter ( E- Probe GND ), Letter ( B - Probe ), 3 wire connector to
coolant sensor and engine ECM, Letter ( A -ECU 5 volt ), Letter ( C - ECU signal ), Letter ( D -ECU
Com. ). With top tank filled with coolant and 2 wire sensor connected, start engine the coolant
Level sensor light will go off.    By update to 2 wire sensor you will add, coolant level high signal, and
coolant level low signal. With the 1 wire old style sensor, present coolant level 5 volt supply and
Coolant level return. If you have a silver leaf or Aladdin, your Fault Code will be 422 coolant level
sensor fault with 2 wire update. Again this is a derate engine fault code to 1100 rpm and cannot
Be cleared untill problem is corrected. In most cases the circuit board for $ 37.00 is the problem
Dave Atherton Retired Cat Mechanic

[Russell Dale]

Dave, talked to Monaco today and stayed with the 2 wire sensor. The second wire is just a ground. Hooked it up like that and the coolant level low light went out. I appreciate all of the advice! Now if I can just finish changing out the cooling unit on the Norcold I will be ready to go again.

Russell

[Edward Buker]

Russell,

That sounds very similar in design to the old one wire sensors used in earlier Beavers with metal tanks. The ground was through the metal threads to the tank to the coach engine/frame. In your case the metal tank is gone, so they wire one side of the sensor to ground using an extra lead.

Later Ed