whitefish Report post Posted July 27, 2011 We have heard a clicking from the fuse box under the driver side dash. It appears to have been related to the aux.start switch or isolator relay. We now are not able to energize the starter from the ignition key. Access to the relay area seems to be behind the fuse circuit board and would require its removal,is this in fact the case and how do I diagnose the problem of switch or relay? Thanks for any comments and help. Doug Robinson Share this post Link to post Share on other sites
ClayL Report post Posted July 27, 2011 The AUX relay/solenoid is usually activated by the Run terminal on the ignition switch or by the Aux start momentary switch. If the relay fails it should not affect the starter. All it does when activated is connect the starting battery and the house batteries. Sounds like an ignition switch or bad connection problem maybe. Share this post Link to post Share on other sites
wolfe10 Report post Posted July 27, 2011 We may be talking about different devices here. The Auxiliary Start Switch= Battery Combine Switch= Battery Boost Switch is a device for connecting CHASSIS with HOUSE battery banks. An IGNITION SOLENOID (not to be confused with starter solenoid) is a device that, when energized by the ignition switch supplies chassis battery power to all items that only work when the ignition is on. Items such as starter interlock, dash HVAC fan, etc. Do all other functions that normally work only when the key is in the ON position work? If so, the ignition solenoid is OK. If none of them do, the ignition solenoid is not working. This could be caused by a bad solenoid or a ignition switch or wiring from switch to solenoid (solenoid not receiving signal from ignition). Brett Share this post Link to post Share on other sites
whitefish Report post Posted July 27, 2011 Hi thanks for the replies. All other ignition items work when the key is on. Mounted on the fuse panel is a red button labelled Aux start switch with instructions to test:turn off engine,disconnect shore power and press. Isolator relay should click,,,,,no click. Any thoughts? Doug Share this post Link to post Share on other sites
desertdeals69 Report post Posted July 29, 2011 Test voltage at the solenoid when red button is pressed. Volt meter black lead on the solenoid case and red to small terninal. If voltage is present and no click solenoid is bad, if no voltage try black to chassis ground. Share this post Link to post Share on other sites
