Cummins ISB 5.9 Cranks but no fire-ECM power.
99 Holiday Rambler Endeavor 37CDS4 with Cummins 5.9 and Allison 3060. 180k miles. Just did a lot of major repairs including the following: -Cylinder head rebuilt, including new OEM sensors and cam se...
Forum Discussion
You have found that 12v can back feed at times making diagnoses difficult.
The fact that your step is not responding properly implies there may be some
kind of problem in the ignition circuit. Add to that the key start works only
about 50% of the time makes it look even more like something in the ignition
circuit.
I would try repairing the step and hope that will repair your no start
problem too.
Ignition switches are relatively cheap you could try replacing it.
I think you can reach up behind the ign switch to make sure the wires are not
loose
It doesn't seem likely 5 different ECMs would all be defective.
I just read a thread on IRV2 where a poster had the same issue
A new ignition sw fixed his.
https://www.irv2.com/forums/f115/ignition-switch-516512.html
The fact that your step is not responding properly implies there may be some
kind of problem in the ignition circuit. Add to that the key start works only
about 50% of the time makes it look even more like something in the ignition
circuit.
I would try repairing the step and hope that will repair your no start
problem too.
Ignition switches are relatively cheap you could try replacing it.
I think you can reach up behind the ign switch to make sure the wires are not
loose
It doesn't seem likely 5 different ECMs would all be defective.
I just read a thread on IRV2 where a poster had the same issue
A new ignition sw fixed his.
https://www.irv2.com/forums/f115/ignition-switch-516512.html
