Mex - Here's a post with info to force the wfco converter into boost mode:
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/24492263/gotomsg/24501414.cfm#24501414A few of details of course:
1. Another forum member tried the modification on his and it didn't work. I've done it to 3 wfcos, a 9845 and two 9855s, and it works on all of them.
2. I've run across 2 similar but different control boards. The pin assignments for the micro are the same. The reset on the control board in the linked post is level triggered. On the other board I ran into it's edge triggered and the reset circuit is different. More than these 2 types of boards? I don't know.
3. I suggest using a smaller resistor than the specified 47k. On the 2nd type of control board 47k didn't pull the sense voltage down far enough, and a lower resistance doesn't seem to hurt anything.
For more info, see the first post in the thread. In the first 2 photos you'll see 2 white power resistors standing up. These are the resistors that get too hot and lead to the majority of the wfco failures. If you want to enhance reliability, get those resistors off the board up into free air space. Heat sinked would be even better.
