A dark screen can be a bit puzzling and scary to an owner. Without the SilverLeaf touch panel, many systems on the coach are difficult or impossible to access. Fortunately, this problem is typically pretty easily solved using a couple of spare automotive fuses.
Newmar coaches utilize a module called an LVDFET to prevent brownout conditions. Actually, there are two of these installed. Essentially, the power for most SilverLeaf equipment passes through one of these LVDFET modules and then passes on to the SilverLeaf devices. If the LVDFET module sees that the voltage is getting too low, it cuts power completely to the devices downstream. Occasionally, these LVDFET modules fail, and power is lost. Thus, your touch panel goes dark. The permanent solution is to replace the LVDFET. But if you’re on the road or camping and the nearest Newmar service center is more than a short drive away, immediately replacing it is not an option. So, how do you get power back in the meantime? Actually, it’s pretty simple. Better yet, you probably already have the parts needed to complete the task.
First, lets look at the difference between the two LVDFET boards. A smaller one, which has only one power protection circuit, is located in the same general area as the SilverLeaf TM-102. In Newmar long buses, this will be in the shore cord compartment. If you’re driving a New Aire, you’ll need to locate the electrical wall in the basement. This is the same wall where the house battery disconnect solenoid is mounted. This smaller LVDFET board only supplies power to the TM-102. In the event that this module loses power, there is a similar workaround for that, but for this article we’ll focus on the larger LVDFET board.
This larger board has two separate power protection circuits – one for the front of the coach and one for the rear. It is possible for only one circuit to fail. In this case, one of your touch panels would still be powered (assuming you have two panels in your coach). In Newmar long buses, this board will be located in passenger-side bay four between the frame rails. If you see a SilverLeaf TM-250 Load Manager or TM-229 Floor Heat Controller, you’re in the right area.
The LVDFET board has two power wires coming in and two going out – one to the front of the coach and one to the rear. All of the wires are terminated with spade connectors, which happen to be about the same size as the blade contacts on a standard automotive fuse. Because of this, we can simply connect an input wire to an output wire through the fuse!
Just pull the wires off of the LVDFET board and slide the female spade connector onto the blade contact of the fuse. The diagram to the right should make this procedure pretty clear.
The size of the fuse isn’t critical. These boards are not designed to prevent over-current conditions.
They are designed to prevent low-voltage conditions. So, if all you have in your toolbox is a twenty amp fuse, that will do just fine.
Once you’ve connected the wires as shown, you should have power back to your SilverLeaf equipment and be back on your feet. If not, give us a call. We’d be glad to help!