Logo
FULL SITE MENU

Engine not shutting off with key

B

BrianRam

New member
I have 454XL 1995 Crusaders. The starboard engine will not shut off with the key. I measured voltage to the purple wire with the key in the off position, and there's none present. I removed the excite wire from the alternator, and the engine keeps running. I also replaced the ignition relay that's mounted on the back of the engine.
I ordered a new ignition module - that's the only other thing I can think of. The only way I can kill the engine is pulling a distributer wire, unplugging the ignition relay or unplugging the ignition module. What am I missing?
 
Pretty sure that vintage uses the MSTS ECU system....mostly to control the ignition timing.

On those, the ignition coil is fed power from the system relay...and that should be controlled by the ignition switch. I'd start with that (relay with contacts stuck together)....as far as turning the engine off, usually safer pulling that relay or the +12VDC connector to the ignition coil...
 
has there been any maintenance actions before the engine doesn't shut off issue started?

if there's no +12VDC on the terminal of the igntion switch (with the key OFF) then something appears to be wrong in the wiring.

Can you verify +12VDC at the ignition coil with the key ON, then start the engine, then cut the key OFF and check for +12VDC at the ignition coil again? There has to be +12VDC at the ignition coil for the engine to run, and it should come from the system relay controlled by the ignition switch. That's typically the source for the fuel pump +12VDC as well...
 
Back
Top