Interrupted Circuits
I have a 2005 Mandalay Presidio 39C on a Workhorse R Series diesel chassis. The coach has two 120-volt-AC ground fault interrupter (GFI) breakers (1 & 2 and 5 & 6) that control all receptacles in the coach. The 1 & 2 breaker is in the kitchen and controls the front receptacles, while the 5 & 6 breaker is in the bathroom and controls the receptacles in the back half of the motorhome. When the coach is hooked up to shore power, both GFI outlets work. But when the motorhome is receiving its electric from the inverter or generator, the receptacles on breaker 5 & 6 have no power. I have replaced the 5 & 6 breaker, which has two wires going to it. One appears to be shore power, and the other goes into a small box next to it. Any help solving this would be appreciated.
Jerry Burke, F361186
Sioux Falls, South Dakota
Bill Hendrix, who has considerable experience working with RV electrical issues, offered the following information about this problem.
I am assuming that you do NOT have an energy management system or an add-on high/low voltage protector. Since you have 50-amp electrical service, there are two lines (legs) of 120 volts AC going to an auto-switching relay, known as an automatic transfer switch (ATS), so there is a relay for each line. At rest, the relays connect shore power to the load, their default position, and are “open.” When the generator starts, the generator power energizes the magnetic coils and “closes” the relays while “opening” the shore power contacts, thus transferring the load from shore power to the generator. It sounds as though one of the relays is not closing when the generator starts. This could be caused by a loose connection (usually slip-on spade connectors are used, but some may have terminal and screw connections). It also is possible the points are burned. If all of these items check out okay, then look for a wiring fault between the relay box and the breaker panel. Follow the shore power line to its termination and that should be the relay box. If you find a faulty relay, it is possible to change it if you can find an identical one. The whole system can be purchased new for between $75 and $150.
Workhorse Owners Manual
Could anyone please tell me where I might purchase or download a complete service manual for a 2004 W22 Workhorse chassis? Any information would be deeply appreciated.
Frede Bidstrup, F398538
Milwaukie, Oregon
Finding information about older Workhorse chassis, such as yours, turned out to be a little more difficult than I expected, and here’s why. Workhorse Custom Chassis LLC, which was a subsidiary of Navistar International Corporation, was purchased by AMP Electric Vehicles in March 2013, and, apparently, the transition is still ongoing. I began by contacting AMP Electric Vehicles. A representative with the company told me that Navistar was still handling queries about Workhorse products built through 2012. Next, I called Navistar’s customer service line at (800) 448-7825, option 7, and spoke with a representative there. He advised me that Navistar is no longer handling Workhorse questions and requests, but suggested that you contact a Workhorse dealer who should be able to provide the manual or direct you to a source. Since you live in the Portland area, he suggested DSU Peterbilt & GMC Inc. (503-285-7771 or 800-556-4998). I hope this information helps.
We also received news that Ultra RV Products (www.ultrarvproducts.com) now carries a complete line of Workhorse parts along with chassis and technical service manuals dating back to 1999. Although the service manual you are looking for is not one of those available for download on the site at the time of this writing, the company is constantly adding new publications as they become available.
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