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Caterpillar C18 Port Side Engine not starting

EcoR1

New member
Hey guys. I have a dual CAT C18 setup in my 62S Azimut and I just starting experiencing an issue with the port side engine. I turn the key and hit the start button and nothing. No noise at all. Voltage at the battery and across the Alternator is good. No voltage to the solenoid when the start is pushed which is what I assume is the problem. The engine was starting a couple days ago no issues, no I assume its something easy/electrical. I have a ZF Marine propulsion control system which has a start interlock system checking for 24v, a control station, in neutral. Since I have two controllers I have verified the port side controller is good which started the starboard engine. Only thing I can think of is that the yellow/red cable running from the controller to the solenoid (I think its NO) is not being passed as there is a break in the cable from the controller to the solenoid. Does anyone have any other ideas I can check? I verified a strong ground to the engine as well. Or at the very least a way to start the engine so I can verify she is still good? Unfortunately I dont have the keys to the maintenance panel or I would try that...

Thanks a lot!

Dustin
 
you need to trace the signal on the YEL/REd wire....until it gets to the starter, it likely won't start...

You should be able to start it with the Key to RUN and jumping the solenoid to the battery....I can't tell you anything about your ZF controller...
 
So following the cable from the solenoid it goes to the caterpillar maintenance panel.. I’ll open that first and see what’s up
 
Ok yellow/red looks like goes to a starter relay inside the cat electronic control box. When key is turned 24v on one side of the relay. When the start button pusher no voltage on the other side.. I will check what’s happening on the sb side but I think this might be the culprit?
 
Update.. Can anyone explain how the Start relay works? I have 24v going to the relay. That said Im confused on how the relay works. Is it supposed to ground the connection when the starter is pushed?

Capture.PNG
 
guess they opt'd not to use the color standards...

the relay feeds B+ to the starter's solenoid to engage it. The relay is 'close' to the starter so it minimizes the length of wire in that circuit. The key switch energizes the relay when it moves to the START position. the relay draws much less current than the starter's solenoid so the key switch can be located anywhere.
 
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