4.3 starting issue

[humpbackshooter]

After searching the forum for the answer, I'm turning in my own question. I have a 97 maxum sr1900. It has a 4.3 LX with the thunderbolt ignition in it. The problem is when I try to start it up, I can't keep it running. When I say I can't, I mean that I can't let off the ignition switch. It will run as long as I hold it in the "start" position. The minute I let it go back to the "run" spot, it quits. I followed the short cut in the "sticky" that Don posted several yrs back, but it says not a thing bout my problem. I tried a new switch but it did the same thing. I cked all the points that was in the sticky short cut:
Check the power at the solenoid C when the switch is turned on..............good
Checked the power at the A post .................good
Hooked my light on A and ck for ground.........good
I don't think it's in the starter unless the ignition circuit goes through it. It's something in the circuit that is open in the "run" mode. Could it be in the safety circuit? Cause the last time I run the boat, I had a problem with the safety horn going off. I carried it to a shop up at the lake and they checked over and could not find a problem. So we cut the horn wire and I monitored the temp and oil gauges the rest of the time. I ran it another 5 days with no issues. I think the problem may have been where I took and washed the engine compartment off/ out and may have shorted something. That's another question for later. But like I said, it ran like a top, just no safety horn. How that was 2 yrs ago too. Boat has been sitting since that time. (Building a house) Or does the distributor have any thing in the run circuit? Following a wiring diagram that I have, I see where the red/purple wire goes into it also. With a several other wires too. Any help would be greatly appreciated.
Phil

I do have that same test light that is shown in the "sticky" along with a flute multi-meter.

 

[alldodge]

Glad to hear you ran though the start issues in the adults only section, most don't even look. Your engine does start so kudos but this is another issue.

Need to find out if you have 12V at the positive side of the coil with the key in the ON position. My guess is your loosing the 12V. Put your meter on it and see what you have. If not there back track to the key switch and see if there is 12V there when the key is on

 

[humpbackshooter]

Thanks Alldodge for the reply. If your r talking bout the starting coil, then the answer is no. The one that has yellow/ blue strip on it and the black that goes to ground. This only has power on it when I try and start. On the top two poles is the red and yellow that goes to the starter. I will say that my ignition switch is only a 3 pole switch. Red w/ purple strip on the batt. Yellow w/ blue strip on the. "S" pole. And purple on the "ing" pole. There has to be some where the invention circuit is open. That's May thoughts but I can't find it in the drawings. Or I cannot follow the wiring drawing.
Thanks
Phil

 

[humpbackshooter]

Alldodge where does the purple wire go from the switch? Stupid question I know but I need to under stand. It's like it splits into several different directions.
Thanks
Phil.

 

[humpbackshooter]

Found something about a ignition sensor. Got to check for this. Where is it located? 3:40AM I'm searching the problem. Can't sleep. It will be a long day Monday.

 

[humpbackshooter]

How does the ignition sensor come in to play in the running of the motor? I'll have to take some pics and post so that I know we're talking bout the same thing.

 

[alldodge]

Power comes in on the Red/Purple and when key is turned to ON or RUN, power is applied to the I terminal and all Purple wires should go hot (12V). When key is turned to Start the Yellow/Red wire goes hot to crank engine

 

[Bt Doctur]

you need to take a 10 minute chill. The alarm circuit is hooked to engine temp, oil pressure and outdrive oil level.
One should never cut an alarm circuit unless one has plenty of money.
power from the key goes thru the main engine harness plug and then to the engine components.
from your style of questions I feel you could use some more knowledge of how things work.,
posting the engine serial number would be good too.

 

[humpbackshooter]

Bt Doc......I could not agree more......on cutting the alarm circuit. ( bro in law did that and it cost him an engine rebuild.) I did take it to a boat shop and they said that there was no problem. They could not find the cause of why the safety horn was on. They checked all the above and all checked good. I watched the gauges the rest of the trip and the boat ran fine. I will have to ck this issue again, but for now I have to get it to run 1st. If the engine will not run then its not in the alarm circuit. This only brings attention to a low oil for the drive, or a low / no oil pressure problem or a temp problem.

Alldodge...I will have to ck the purple wires at the engine compartment. I read some where last night where you posted some step by step test to check the ingintion sensor. I will find it and print it out and check there too. I feel like that is where my problem lies. I found a manual ( #25 mercur ) Still got to look through it.


Thanks for yalls insight.
Phil

 

[Bt Doctur]

take a jumper from the battery to the + side of the coil, see if the motor now runs.

 

[humpbackshooter]

No Title

Bt.Doc......Thanks. I will try that when I get home. I also posted a pic of the serial plate on the back starboard of the engine.

 

[humpbackshooter]

If I have 12vdc on any of the purple wires in the engine compartment......that means that I have got power back to the engine compartment and there is not a problem up front under the dash?

Phil

 

[Bt Doctur]

You can activate the starter so power is getting thru the system components up to the dash. some have an ignition fuse on the purple wire under the dash 20A. start there tracing the wire. should see 12v with the key on. then go to the main harness plug. loosen the clamp, pull it apart and apply some cleaner or some grease, reinsert and snug the clamp. Go to the + side of the coil, check for 12v there.
report the findings.
Service Literature for MERCRUISER TB5, W/PS, 3"RISER, WORO, GEN+ 4.3LX ALPHA
PARTS CATALOGS

• 809969 96 - 4.3 LX/LXH ALPHA and BRAVO (GEN +)

 

[humpbackshooter]

Is that info from the mercruser manual #25?...........your fast.

 

[humpbackshooter]

what a cheap, lying, no-good, rotten, four-flushing, low-life, snake-licking, dirt-eating, inbred, overstuffed, ignorant, blood-sucking, dog-kissing, brainless, dickless, hopeless, heartless, fat-***, bug-eyed, stiff-legged, spotty-lipped, worm-headed sack of monkey s*it move. Hallelujah. Holy sh*t. I found the problem. After checking the for 12v on the coil, I started looking under the dash....when I notice the safety switch looked like it was on.....BUT was pulled just enough to be OFF. Where's the Tylenol?

Thanks Bt doc & Alldodge Fair weather and smoothe seas to ya!!!!!!


(Now on to the "safety horn issue. I'll start a new thread on this.) (Or search the thread)