Electrical riddle

[kraus6451]

I have an electrical problem on my 2010 wamilton superjet and was wondering if anyone could help me with whats going on. I am using the wiring diagram attached. I currently have the starter switch taken apart so that I can jump power across the switch with a wire. On the hot brown wire there is 12 volts but will not start the motor with the switch. With the terminals connected together with a jumper wire the starter motor won’t crank.. On the other terminal there is the brown wire that leads to the starter solenoid; I can jump 12 volts straight from the battery and the starter motor will turn over.When I jump the two terminals with a cable, simulating the start button being pushed, there is a 0 volt difference between anywhere on the brown wire and the ground.

Any help or suggestions are appreciated. Thanks in advance.

 

[OCD Solutions]

If you follow the brown wire on the left side of the start button diagram, you will see that it goes over and goes through a set of normally closed contacts in the engine stop switch for the tether. Those contacts are not closed as they should be so there is an interruption in voltage to the solenoid.

If the tether is attached, then you need to pull the tether button apart and see why those contacts aren't closing.

 

[Pro-pulsion]

This may sound silly, but have you looked at the condition of the fuse and fuse holder? If you follow the brown lead going into the start switch it exits as a red lead. That runs down to the voltage regulator where it branches off to the fuse and battery positive terminal. If the fuse is defective at the soldered locations under the metal end caps it might only allow a volt or two to get through...similarly if the fuse holder itself is corroded or varnished from oxidation. It will act as an insulator rather than a conductor. You would need to polish the inside of the fuse holder with some emery cloth and get that shiny brass look back...and do yourself a huge favor in the preventive maintenance department, coat the fuse end caps with dielectric grease to keep the fuse and holder from weathering in any way shape or form. The best advice I have ever been given and use it as my rule of first approach...look at the easiest things first. If the fuse is good, check for any bad spots in the wiring (kinks, bare spots from rubbing against somewhere creating a short to ground, unplugged, pinched, etc.), if the wiring appears to be good, check for a ground fatiguing or just completely not grounding. Typically these areas are the likely suspects, very rarely have I ever needed to dismantle a switch.