carlvik Report post Posted December 10, 2011 I have a 1995 Holiday Rambler Navigator w/ Cummins 8.3L 300hp engine. Lately I have noticed that when I turn on the ignition switch to start up, the wait to start light does not completely go out. It dims to the point that it is still barely visible throughout the whole time that the engine is running. Should I be concerned? New to diesel engines since July 2011. Share this post Link to post Share on other sites
wolfe10 Report post Posted December 10, 2011 Carl, Welcome to the FMCA Forum. If you don't get an answer here from someone who has experienced this problem, on Monday, call Cummins 800 343-7357. Have your engine serial number handy. Brett Share this post Link to post Share on other sites
dickandlois Report post Posted March 9, 2012 This is and older post an I have no idea if you have resolved the issue. However! The per-heaters are controlled by the Engine ECM. They are powered from the batteries through two 100 amp. self resetting circuit beakers that connect to 2 heater coils in the intake manifold, the circuit(s) are controlled by 2 ECM circuits using relays. One for each heater. The connections can get corroded or one of the beakers or relays could have failed. One of the heaters may not be working or being sensed by the ECM. With a meter read the return side voltage,that will be the wire going back to the ECM. Best test is when things are cold. If the reading is 12 plus volts on one of the return circuits and not the other, there is an open circuit between it and the ECM or and ECM problem. Should you read zero volts or close to it on just one, there is a chance of an open heater. With the key off read the resistance of both coils,are they the same? If not and on reads open,bad heater element is a possibility. R.M. Share this post Link to post Share on other sites
