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Dead in the water electrical problem

dhyams

Regular Contributor
"Well, I tempted fate and lost

"Well, I tempted fate and lost....boat went dead in the water while on-plane...had to be towed in.

1996 4.3LX, Alpha one; 18 ft ski boat, 2 bbl carb.

For some reason, the purple wire back in the engine compartment goes dead....it's the one connected to the electric choke and the positive side of the ignition coil. I *thought* that the problem was the kill switch...following the purple wire back, I saw that it went through the kill switch (at the throttle) on the way, so on the water, I spliced/bypassed the kill switch to take it out of the loop. Still no dice, but I'm also not convinced that my splice job out on the lake was secure.

So I guess my question is...what other things might cause the purple wire to go dead? It seems intermittent...for example, last night I messed around with the wires near the throttle (in addition to re-securing the splice that I had made above), and suddenly the purple wire was live.

I still have trouble starting it after it dies from this though...is it possible that the engine gets flooded if the ignition coil cuts out in the middle of operation?

Other relevant info:
* ran the boat aground a few days ago; was only going 5mph, and only the skeg and prop hit. But I'll have to admit, I didn't have a blatant electrical problem like this until after that. Could be coincidence.
* have been having cold starting problems as described in this thread: http://www.marineengine.com/discus/messages/12486/191402.shtml

Again, thanks guys for any input you might have; hopefully soon I'll learn enough to be able to contribute more to the forum rather than being the one always asking questions *embarrassed*."
 
""It seems intermittent...

""It seems intermittent...for example, last night I messed around with the wires near the throttle (in addition to re-securing the splice that I had made above), and suddenly the purple wire was live."

Daniel:

You have narrowed the problem w/basic "tug-N-pull" trouble shooting on the purple wire. The purple wire has either an "intermittent" internal break or has heavy internal corrosion.

Disconnect the barrell plug to the engine and the purple wire at the choke and connect an ohmmeter on the 1K scale between the purple wire and pin #5 on the engine part of the plug. While you hold the purple wire choke end to the meter probe, watch the meter and bend, shake and twist the wire to see if it loses continuity.

When you see that it does then start to coil the wire in a small circle while watching it for a dimple or bump on the insulation. You can also run the wire between the thumb and forefinger nails to feel the change.

When you find one that is the problem point. NOTE: When stripping back the insulation for a new connection, if the copper wire is NOT bright but dark and dull; replace the wire.

Repair w/a double ended crimp connector and shrink tubing or replace the entire wire from the choke to the closest junction and RETEST."
 
"The purple wire is the main s

"The purple wire is the main switched hot wire to the engine harness.
Two likely causes (other than the kill switch):
-flakey key switch. If your guages go dead when the engine dies, this is your likely culprit.
-intermittent connection at the 10 pin barrel plug on the engine. This can be fixed by thoroughly cleaning the pins and sockets and resealing.
If neither of these turns up your problem, then its a wiring issue as Guy suggests.

Rod"
 
"Thanks Rod and Guy; you guys

"Thanks Rod and Guy; you guys are so helpful....

Concerning the key switch...all guages are live, so I think I'm ok there. I'll check out the barrel plug; I disconnected it yesterday and didn't see anything wrong. What does "resealing" mean, though?

Another weird thing that I just thought of...I was poking around doing some continuity testing on the purple wire, and just for the heck of it, I touched one probe to an exposed part of the purple wire (exposed because of a splice) and one probe to the flame arrestor. I didn't expect to see continuity there, but there was. Zero resistance....just thought I would bring that up, because I thought it was very strange."
 
"Daniel;
Using your test ligh


"Daniel;
Using your test light, see if you have 12 volts at the outlet side of your kill switch.
If so, and your engine purple wire is dead, then there is an issue with the wiring between.

You are likely better off in this case to run a new length of 14 guage purple wire from the kill switch to the engine purple harness, and bypass all in between. This will be faster than trying to chase wiring gremlins in dark recesses of the bowels of your boat whilst standing on your head.

I suggest if you do this don't dick around with the wrong color wire. Get some 14 ga purple from AutoZone and do it right.

Rod"
 
"Zero resistance...."

"Zero resistance...." I would follow Rod's advice. Make your purple wire connection on the engine at the first junction you trace it to. Make another after that if you have to do it.

If you cut out part of the circuit by jumping around it then you'll lose voltage to other parts of the engine. Be sure the choke ground wire is well grounded.
 
"I was chasing a similar probl

"I was chasing a similar problem, turned out to be the Tachometer was shorting out, removed the lead from the coil and I haven't had a problem since."
 
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