300xs no start?

[mikeym]

heres the story... i got the boat back friday afternoon from getting a #6 coil, 2nd #6 coil in 2 months(merc tech says its showing a short on #6, coil doesnt seem to be bad as it will start to work fine?). splash the boat yesterday afternoon, immediately the ignition coil alarm goes off on smartcraft. high idled the boat for a few minutes, alarm goes off, boat runs fine. picked up some folks and went to dinner for 2hrs or so. get back in the boat, alarm goes off again. idled out the creek, alarm goes off, we run off to another bar. 4hr later, pack up and run the boat back to the house- everything is great. we stop at a dock to talk to some folks about to head to the stream, and shut the motor off for about 5min. go to crank back up- everything is dead. the house battery was understandably dead, the radio had been jamming out all day with a big amp, and it hadnt recovered yet. the motor has its own batt, and it would just click when it turns over and tilt trim was very weak. paralleling the 2 batts was useless as the house was weak. i plug in the charger, and let it be for 8hr or so. the charger showed everything at full juice, but still no cranky and still weak tilt/trim- though intermittent, sometimes it would trim fast, then it would slow down. i swapped in the well charged house battery to start, it did nothing. hooked up a jump pack to the well charged battery, nothing. i have undone every power and ground under the console and motor, inspected, and retorqued down, still nothing. no fuses or breakers are blown/tripped that i can see. im at a loss, and we are supposed to haul the boat 600mi south on wednesday for a fishin tournament! any ideas? im gonna haul it back to the dealer monday am, but im curious if it may be something i can take care of myself...

thanks

[EuropeanAM]

I'm assuming that you've cleaned and tightened the battery cable connections WITH SS LOCKNUTS (not wingnuts)?

Follow the battery cables into the cowling of the engine. Confirm that the positive and negative cables are tight at their connections ON THE ENGINE.

We often see either of them loose- ESPECIALLY the ground cable (it attaches to the engine block just below the starter). Actually attempt to rotate the cable on the attaching bolt- if it will move around, it is loose!

This type of connection issue could also cause the warning horn you describe in your post (LOW VOLTAGE).

[mikeym]

all connections are tight with ss hardware. i have undone everything and retightened, and still no start. im not getting low voltage on smartcraft.

i just went out and jumped power from a new battery, out of my truck so i knew it wasnt dead, direct to the motor, and still get nothing but clicks. is it possible the starter has gone bad?

[EuropeanAM]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mikeym &raquo;</TD></TR><TR><TD CLASS="quote">all connections are tight with ss hardware. i have undone everything and retightened, and still no start. im not getting low voltage on smartcraft.

i just went out and jumped power from a new battery, out of my truck so i knew it wasnt dead, direct to the motor, and still get nothing but clicks. is it possible the starter has gone bad?</TD></TR></TABLE>

That is indeed possible. One more item you might check- there is a solenoid mounted ON THE STARTER ITSELF. Check for power on the yellow wire with a red stripe when the key is in the "start" positition. Of course, this wire should be "connected" to the starter solenoid (have seen a few of them come loose).

[mikeym]

everything is tight, i checked connections on the starter solenoid this morning. everything everywhere is clean and snug. i do not have a volt meter to test is the yellow wire is hot, but i know its connected. im investing a lot of faith that the merc mechanic can figure it out early enough and get something overnighted. this 300xs has been a nightmare, certainly the last one i will ever purchase. in the last 40hrs its had 3 coils, a computer, and now this...

[EuropeanAM]

IF you have a small jumper wire.... you can, at the starter, jumper from the large "RED" wire to the smaller "yellow wire with a red stripe". Starter should engage when you do this.

If it does NOT, you either have inadequate voltage/amperage supply, or the starter is bad.

[mikeym]

i dropped it off 2hr ago at the dealer, im hoping its just the starter. would you have any idea what would keep shorting #6 coil temporarily? the ignition coil alarm will sound, the motor will only run on 5 cylinders and idle rough, then it seems to warm up and run fine until i shut it down again and i go thru the same process...

[EuropeanAM]

Is it actually logging a fault as a "short", or an "open fault"? This is critical....

Shorts can be due to a faulty coil, harness plug melted, coil harness assembly problems, FAULTY TPS (ohms test should read 200 or higher Ohms), OR WATER GETTING INTO THE COWLING (such as from a missing access plug on the port side of the cowling, or a bad cowling seal).