MCI SERVICE INFORMATION

Temperature Controller Rework - D/DL Models

We have had reports of customers having difficulties with the heating/air conditioning on their coaches. One of the reported symptoms is that of the temperature controller on the dash either not reading the proper temperature or going completely blank. The short-term solution has been for the driver to shut down the coach. After restarting, everything works fine.

Permanent damage to the controller can occur if the above symptoms happen too frequently. This situation usually can be resolved by following these steps:

1. With the main disconnect switch in the "OFF" position, open up the central heat compartment door (located in the #3 baggage compartment).
2. Locate the main heater water valve in the upper RH side of the compartment.
3. Connected to the water valve is a two-wire harness consisting of a black power wire and a white ground wire. On the harness side of the inline connector (not between the connector and the water valve,) cut the white wire (circuit #36A) about 10 inches from the connector.
4. Crimp a #10 ring terminal (part number 19-11-483) to the 10 inch length of wire that is still attached to the connector. You will need to strip off about ¼" of insulation from the wire before crimping on the terminal.
5. Remove the LH mounting screw from the drip tray, which is fastened to the coach below the water valve. Place the ring terminal over the screw, and re-attach.
6. Tape the remaining end of the cut white wire that is still in the coach harness.

MCI has issued Service Bulletin #2769, which explains this procedure in much greater detail.