I have a 2011 Serrano 33A with a maxforce diesel. When I try to start it, it is like the batteries are dead. Batteries are new and charged. If I step on the brake and recycle the ignition switch sometimes it starts. Any help appreciated.
If I go straight to crank position on ignition switch it will start. If I pause in run position for a few seconds to wait for glow plug light to extinguish and then move ignition switch to crank, that is when it will not crank. Any ideas?
Started again about three weeks ago. Carried to local International Harvester/ Navistar / Workhorse dealer's service department for diagnosis and repair. They have had the coach for two weeks and cannot figure out why the start relay is losing ground during the crank cycle. This is a W22 chassis with a Navistar Maxx Force 7 diesel engine. Most times will crank and start if you go straight to start position on ignition switch without pausing when turning through run position. If you pause in run position any length of time then the start relay is losing ground and starter will not crank.
There was a broken wire somewhere in the wiring harness between the neutral safety switch and the start relay located in the under-hood electrical box. Took the the local Navistar dealer two weeks to figure it out and $2600 later they ran a new wire from the neutral safety switch to the start relay. Has worked fine since.. Good luck.