225 sho blowing fuse. help please

[walleye1]

I have short harnesses I use all the time.

[99yam40]

I did test the main relay and it tested fine as well. Input voltage was 12 v in both key on and key off positions. Also checked each relay for continuity (closing) with 12 volts supplied and they open and close circuit as they should. All connections were very clean. This boat is garaged and the powerhead was replaced under warranty in 2013. Looks practically new. Battery is 9 months old and terminals very clean. Don't get me wrong, I pulled it all out, cleaned it up anyway and tightened everything securely. Power trim could be involved or maybe just coincidence, I don't know. I do know I felt a huge drop in power each time I touched it but there may have been something else going on at the time and the trim motor kicking in would have made it severely worse from a power standpoint. I am going to begin to trace wires and equipment in the boat. With those keypads, 4 tilt and trim switches and gauges in the console I want to rule out any shorts if possible. Not going to be easy though, Ranger uses too much expanding foam.

I would fall back to the low voltage reading and chase that if it still exists.

that fuse only feeds the ETV if the prints are wrong as we think they are.

which connector being disconnected stopped the fuse from blowing?
the one from the relay to ECU or the one from ECU to the EV?
need to make sure, since if it is only the one to the ECT, the ECU may be OK and the problem is in between the ECU and the ETV. If it was the one to the ECU from the ETV relay then it may be in the ECU

I have read where hitting T&T draws enough juice that it drops voltage due to a bad connection somewhere the ECU does not like it and drops stuff out.

but that does not address the fuse blowing all of the time.

Looking at the print again, it seems both inputs and outputs for the ECT to the ECU are on the same connector, so not a easy way to separate them like I was saying

[99yam40]

Take it to a dealer that can hook a 703 control box up to your engine and see if it is still blowing the fuse, that will tell you if it in the boat or not.

I Myself do not see where something in the con*****er or boat could blow that fuse

[walleye1]

Could be a screw through the harness.

[99yam40]

the harness to the control box does not go between the ECU and the ETV, all of that wiring is on the motor itself

how hard it it to pull the pins out of the connector to the ECU so they can be eliminated all together or one by one?

[walleye1]

I will look to see if there are only one yellow wire [key on] in the main harness.

[walleye1]

Te
here are more than one, from key switch.

[99yam40]

Have you read any of the thread about what fuse if blowing and what it feeds?

[walleye1]

Does not mater, it only hapens when key power on.

[walleye1]

You are rite, looked again it has to be on the engine.

[HarrisonDawgs]

99yam, the uppermost ECM coupler (largest one of the three) was the one I disconnected and left everything else in order when the fuse survived 5 start attempts. Page 5-24 of manual listed as coupler "a"

[99yam40]

99yam, the uppermost ECM coupler (largest one of the three) was the one I disconnected and left everything else in order when the fuse survived 5 start attempts. Page 5-24 of manual listed as coupler "a"

yes looking at the print it looks like that one connector has the inputs and out puts of the ECU to the ETV, just in case you missed what I wrote before.

is it possible for you to test those pins/wires on the connector/plug and on the ECU for a ground?

just for your ino, I have never worked on a motor like that.
I am just going off of what I see posted on prints and manual posted

but I was an auto tech, and then an electrician/ instrument tech in my working life for many many years
I still like to figure out how things work like I have all of my life.
should have been an engineer I guess, but did not like school that much to waste years taking stuff I was not interested in

[HarrisonDawgs]

Wiring in that coupler includes, OCV (both stbd and port), vapor shutoff valve, ETV (ground, motor open, motor close, 2 power sources, ground) engine shutoff switch, diagnostic flash indicator, overheat alert, oil pressure alert, alert buzzer, all 6 ignition coils and fuel injectors, hp and lp fuel pump, tach and strangely enough - ETV RELAY...So, I supposed leaving it unplugged prevents the ETV relay from closing thereby saving the ETV fuse from Armageddon. Did not notice this the first time I looked thru the list. So the Ghostie I suppose is that power leaves the main relay thru main fuse to ECM then signal flows back to control box to activate the ETV relay to close and supply power to blow the ETV fuse. Guess I need to concentrate on following the current path from the fuse to the ETC/throttle body and disregard the ECM...unless it takes another pass thru ECM to its final destination.

[HarrisonDawgs]

I have tested all of the plug connectors on ECM harness (a) for ground. 3 are dedicated grounds and indeed were grounded. None of the others showed any continuity to ground at the block grounding bolt. I checked a few of the pins on the ECM, mainly the grounds, but abandoned that idea b/c if I were to find an unexpected ground on ECM pin it likely means the ECM is shot. That may be the case (don't think so) but by then the motor will be in the hands of a certified mechanic with YDIS. I'm doing my best to rule out something simple here. Once I've ruled out all the simple stuff I'm taking it to someone higher up.

[99yam40]

my thoughts would be to follow/test the wires&pins from the ETV relay to the ECU, into the ECU, and then back out of the ecu to the ETV both paths.
one of those has to have a problem.
if the ETV fuse is to protect the ETV then I think the ECU just switching that power on, not using other power after it gets there