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+--- Thread: No Crank (/showthread.php?tid=6245)
No Crank - rapidisimo - 06-07-2020
2011 Prostar cm871. Does anyone know where the crank relay is located on this truck? Looking at this wiring diagram from international is not really helping me. I need some help trying to diagnose this no crank issue I'm having. Does it even have a crank relay? Is it in fuse box?
RE: Crank relay - Rawze - 06-08-2020
that is the wrong diagram for a2011 truck. The circuits are not the same in a 2016 truck as they are in a 2011.
here are the avail. diagrams...
http://bodybuilder.navistar.com/General/BBcircuitIX.htm
Yours is 2011 year model, meaning it was likely built at the factory before june of 2010. This is the diagram that matches my own 2011 prostar ...
http://bodybuilder.navistar.com/General/Documents/svcmanpdf/s08339.pdf (fuse F8-H is found on page 13, 102).
RE: Crank relay - Rawze - 06-08-2020
Could be the keyswitch but just as likely...
Prostars are notorious for getting tarnished fuses in the fuse panel. REPLACE ALL FUSES AND BREAKERS AND RELAYS that have discoloured contacts. Here is some related info:
http://rawze.com/forums/showthread.php?tid=1514&pid=12861#pid12861
I have had to change my fuses out (the ones mentioned in that post) every few years or so and go through and clean up all the contacts of the breakers and relays a few times over the years as well.
There is a starter relay, but the high-amperage contactor that feeds the starter motor is mounted to the starter itself. there is also usually a heat sensor on the starter that prevents cranking if it is hot/triped too until it cools off. Those heat sensors are known to fail as well, but since you say your gauge cluster is acting up too, I doubt it is on the starter alone.
* battery connections.
* Grounding connections.
* Those big master cabin fuses that are exposed to the weather and salt corrosion out at the firewall that are in the weather (located near the air-cleaner on the drivers side under a rubber cover).
* Something shorting out like an inverter with poorly-made wiring can cause surging, leading to sometimes gauge cluster resetting and all kinds of other weird no-start or engine dying issues.
* Bad ecm.
* Tarnished fuses in the fuse panel.
* Key-switch going bad.
* Other shorted out wiring.
the list goes on and on.
RE: Crank relay - barf - 06-08-2020
The clutch pedal safety switch has been the culprit for mine not starting in the past.
RE: Crank relay - rapidisimo - 06-09-2020
Found the no crank problem I was having. The little wiring harness that plugs into the front of the starter was causing my problem, I believe that's for overcrank protection. Sorry, didn't take a pic but the wiring going into the plug was corroded. Replaced the wiring and now it cranks everytime. Thanks again for your suggestions and input.
RE: Crank relay - rapidisimo - 06-10-2020
Here's a pic of what was causing my no crank issues. Even after installing a new starter it still didn't crank because the wiring was faulty going to the plug. Hopefully this will help someone else that's experiencing no crank issues and can't figure out why.