Trusted Contributor

Re: ECM negative at ground connection

Looks like your dealer has no clue about a marine installation.

which is pretty normal around the world.


yes your ground should be potential free, soo NO contact is allowed between + or - and ground.

the fault can be created in the alternator, startermotor, ecm or any sensor or injector system.

if the system is under warranty they have to fix it.

Cat Dealer

Re: ECM negative at ground connection

No. Uselly the engine got a float negative. If you have continuity with negative battery, the engine have problem with electric component.

New member

ECM negative at ground connection

We have a 24VDC low insulation sensor in the ship and when the ECM is power up to start the 3516C engine the low isulation alarm turns on.
Caterpillar local provider told us that this condition is normal because is the system right operation to use negative at ground.
It is real? Is any way to avoid negative to ground in the ECM? Provider said no way and if any try to avoid the CAT guarantee could be lose.