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Wiring problem

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roederll

Regular Contributor
"I have an 888 mercruiser ster

"I have an 888 mercruiser sterndrive, there is a switch on the back of the engine on the top of the engine. It has two purple wires i believe coming from it and they go somewhere important, but i do not know where they go to. I have a manual and it looked like it said they go to the coil and one to ground, any help would be greatly appreciated."
 
A picture would help maybe? I

A picture would help maybe? It is true that usually the purple wire goes to the ignition coil. Does it look like a previous owner (if there was one) wired this up?
 
"The previous owner didn't

"The previous owner didn't have them hooked up at all. Thank you rod for saying it was the shift interrupt switch, i new that just couldn't remember it and didn't have the book in front of me. I will try to get a picture available tomorrow. Thanks."
 
Without the shift interrupt sw

Without the shift interrupt switch it will be very difficult to shift out of gear.
I suspect that one wire will go to the coil hot terminal and the other to ground. I will confirm this tonight when I get a chance to look at the wiring diagram.

Rod
 
"Louis;
I checked and one wir

"Louis;
I checked and one wire from the switch goes to the coil - terminal, which should have a brown wire on it, and the other should go to ground (black).
You should check the switch before you hook it up. It should be open normally, and closed when actuated by the shift cable mechanism.

Rod"
 
"I also have another question.

"I also have another question. More or less about the lower unit. I took it off a couple of years ago to replace water pump. I took the boat out the next day and it was running like a top then all of a sudden the engine lost power and cut off, i could start the engine, but it wouldn't engage the gear to go forward or reverse. It was all thrust but the propellor wouldn't move. I was thinking i may have put the two (lower and upper units) back together incorrectly. It wouldn't engage either way. I took it off again to day to see what i could do with it, and i can get it to engage one way but not the other. Any ideas."
 
"Check your drive oil and magn

"Check your drive oil and magnetic drain screw for metal particles.
If the oil is clear, sounds like it could be a cable or linkage adjustment.
Maybe pull the two drive halves apart and see it they are OK separately.
See what you find.

Rod"
 
"Well i remember their was NO

"Well i remember their was NO metal shaving or particles on the drain screw. Their has always been play in the throttle at the helm, but i've looked at the shift shaft outside of the boat on the lower unit, it seems to move, but it doesn't move a lot. I can't imagine that it would move too much b/c all it does is engage fwd and rev. When i took the two apart this morning the drive shaft out of the top of the lower unit looked fine aka the spines. I tried to look up in the upper housing to see anything but didn't see anything for lack of a flashlight, was too lazy to go get one too."
 
"Louis;
The lower shift shaft

"Louis;
The lower shift shaft is straight ahead for forward, about 10:00 o'clock for reverse, and about halfway in bettween for neutral. So it does not move much.

With the lower unit off it should move easily by hand through all these positions, and fwd and rev gears should lock solid. If not you have some internal problem with the sliding dog clutch collar, and the lower unit will have to be dissasembled to resolve it.

Rod"
 
With the lower unit off i have

With the lower unit off i have to move the shifter one way to engage it fwd and another for rev. When i have it off as long as i manually shift or turn the piece for shifting in fwd or rev it works fine but when i put it back on it doesn't work correctly when i put it in gear at the helm it doesn't lock in gear either way.
 
"checked the wires and they se

"checked the wires and they seem to be moving, and engaging the gears. But not really engaging the gears."
 
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