Boost Switch

What I want to accomplish is to give you a better understanding of this important feature in your Foretravel motorhome. We have used this for several years, beginning in 1979.

Until 1984, this was a momentary switch that enabled the coach and chassis batteries to both be engaged, to aid in starting the engine when the switch was depressed.

Since then, however, we have designed this as a “charge/boost” switch to function either on momentary or constant. By depressing the switch fully with the light “ON,” the system is constant. What this means is that if 110-volt power is supplied, (generator running or shoreline plugged in) you will be charging all of the batteries. This is accomplished through the power converter.

Conversely, if the switch is turned “OFF” and 110-volt power is supplied, then only the coach battery(s) is charging. When driving, it is not necessary to keep the switch turned “ON” because the alternator will recharge the weaker battery system first and this is accomplished through the battery isolator.

In the event that our alternator would not be charging our chassis battery while driving (due to an alternator failure or the loss of a belt), we can turn the “boost switch” to constant “ON.” Then start the generator and leave it running in order to help recharge the chassis battery until we can correct the alternator situation.

IMPORTANT: Don't forget to turn the switch “OFF” if you are going to dry camp and NOT be plugged into shore power or have the generator running. The reason for this is that you could discharge the coach AND engine batteries simultaneously with enough 12-volt components operating and then not be able to start the coach.

The Boost Switch has a tiny bulb that can burn out. That does not mean the Boost switch is not working. It simply means if you are having problems and are not sure, you need to have it checked. It could be just a burned out bulb.

To replace the bulb for a 2002 and later dash is to get inside the dash and pull the top connector straight off and find the bulb inside. On older coaches you open up the dash and pull the socket out from inside - just a gentle pull does the trick. The bulb number is a common bulb for turn signals, ashtrays, high beam indicators etc.

  • GE 2721
  • Wagner Lighting 17037 Miniature Lamp
  • Napa #73 / NAPA #LMP73
  • Sylvania 2721LL

Thus, this important feature can be used effectively to always insure that we have ample power available whenever we want it.

by Michael Packard - Motorcader