Starter staying engaged

[Mike Rowe]

Recently my port engine starter will stay engaged upon starting, the engine will not shut off with the key and I have to turn of the battery switched to kill engine. Also now when I cut the power to the engine in takes several seconds to shut down. I have changed the relay switch but the problem still is there. Someone mentioned the possibility of a bad diode in the fuel shut off system. I have also swapped the fuel shutoff solenoids and the problem continues. Any help would be greatly appreciated.

Topic

[Tony Athens]

Sounds to me like corroded high resistance connections in may places.. Take all those connections apart, clean and lube with a a petroleum based di-electric like Corrosion X,  Corrosion block, etc.,  and then put white lithium grease on all get tight,..

Where are the pictures I asked for?

Tony

[Francis Valerio]

In the mean time I would swap starters from port to star engines to rule out the starer solenoid possibility.

[Mike Rowe]

Troubleshooting Results

Tony,

Thank you for the response. I had someone with an electrical background walk me through some diagnostics using the Standard B/C engine schematic. Our findings are as follows… Upon starting, ~7 volts present on starter solenoid (yel/red from starter relay to starter solenoid). That voltage from that side of the starter relay is what is causing the fuel shutoff to stay on (other wire on that relay contact goes to fuel shutoff). Starter relay coil voltage drops to zero consistently after starting (not start switch issue). Starter relay has been replaced and coil opens to infinite resistance consistently (with yel/red soleniod wire removed, no load). When yel/red from relay to solenoid removed from relay with engine running starter drops out and engine can be shut off from key. So, the voltage causing the starter to stay engaged appears to be from the starter solenoid itself, however, hammer test did not drop it out. It just seems odd that disconnecting the yel/red from the relay would drop out the starter if that was the case, but it definitely removes the voltage from the fuel shutoff solenoid allowing the engine to shutdown with the key. Have you seen a starter solenoid fail in this manner? Thank you in advance for any assistance! 

Mike

[Francis Valerio]

On some applications the fuel shut off switch/solenoid is a 12V “+” wire (keyed to ignition “on”).  If possibly this wire is getting “crossed” and making contact somewhere in your harness with the 12V “momentary on” (which is connected to your cranking circuit and energized while “cranking”) it could give a similar result of started not disengaging…..possibly.

I would recommend looking at ALL connections that have to do with the starter, the ignition switch, and the fuel solenoid and any relays.  You may have a corroded connection somewhere hidden. 

Sometimes when wires have corroded connections in the circuit (whether they are “+” o “-” they can so some “funny” things like you mention.

 

[Tony Athens]

I want good pictures of the starter and related parts on the engine in that area.

What exact engine?

 

Tony

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