Self Inflicted Wound ?

[Bud Kennedy]

It has really been frustrating working on my 1991 Johnson Fast Strike.  It just seems like each time I chase down a problem and make the required repair another problem begins.  My current problem is something electrical that is blowing the main engine fuse.  To provide some history of my electrical system, I have replaced the power pack, coils and plug wires.  Most recently it was the plug wires.  I have run the motor on muffs and all was good.  Then during the launch the motor shut off when unloading from the trailer due to a blown fuse.  This has never happened in all the years with this motor.  Now I still have a problem.  When I turn the key it immediately blows the main engine fuse leading me to think I might have a problem with the ignition switch.  The switch is original and is 32 years old so my thought seems logical.  I have ordered a new switch but now my mind is wondering what might be the next thing.

Currently my question is that with all these electrical changes going on over the past few months it appears that the failure mode (s) is almost a cascading effect.  With the idea that one thing leads to another could it be that my mostly updated electrical system is just overpowering the original components?  This has been a big time frustration and with each corrective action I seem to experience a new negative problem.  Unfortunately I am already considering what the next failure mode might be.  I would guess something with the starter will be the next area of attention but hopefully not.

[D.W. Verts]

Bud, it's just the way these older engines work and I saw this throughout my whole career. When you replace a weak or broken component the next weakest fails, and so on. Stators, power packs, coils, they all are part of an integrated system. Plug wires are not part of this program, b ut of course need to be replaced from time to time. ANY wire or component with oil on it is suspect- oil-soaked wiring is problematic.

A blown fuse is a little different though. Maybe just a weak (OLD) fuse. But when something like this happens so soon after a motor has been worked on I tend to look for something touching somewhere that it shouldn't touch. Somewhere.

A GREAT tech (I've known a very few) will have some methodology about diagnosing/troubleshooting electrical issues and an order in which to do so. Most just chase down the culprit and replace that part. I'm sorry that I don't remember the order that MY great tech used, but it worked. I myself am NOT a great mechanic, but at one time I could tell you the whole rigmarole. I do remember that Merc and OMC were different, which I always found interesting.

Dale

[Bud Kennedy]

Dale, yesterday I removed the zip ties from the wiring bundle under the console so I could have a better chance of tracing the wires.  I noticed that I the new helm that I have installed may be just touching a small circuit board but could not tell for sure.  I will examine everything in detail tomorrow.
Currently I am all pretty and cleaned up for Mother's Day so it would not be a great idea to start on the project today.  I still have to get ready to prepare a supper for the Mrs. later this afternoon.  Got a couple nice filet mignon steaks to prepare on the grill along with some other stuff.  Besides Sunday is usually a day of rest around the Kennedy house so I will be up and at em tomorrow. 

The circuit board is in a hard to see spot with my one eye so I will have to deploy my LED headband to get enough light to see what is going on. 

[Bud Kennedy]

So far this is the only thing I have found that could be a problem.  When I re installed the helm after the most recent steering cable installation, It looks like one of the bolt/washer from the helm mount is touching a terminal board and is against one of the contacts. 



To correct this I have to pull the steering wheel and bezel to get to the helm mounting bolts.  I will loosen them up to see if I can move just a bit or I may have to move the small terminal board to get clearance for the washer/bolt.

Not sure about other problems but will continue to investigate other possibilities.  Anyway this just may be the culprit just not sure until I make the change.

[BassmanRudy]

Bud,
Is the area (of the washer) touching the terminal black? Sure looks like it arced right there(circled in blue) which def could have caused some issues. 

[Bud Kennedy]

OK the problem has been identified and solved.  Everything is working as it should (for now) It clearly was the washer shorting out the terminal board.  Had to modify a washer to avoid this problem when I put it back together and now all is well and the motor is put all back together.  Almost time to perform a lucky me dance.  Makes me wonder what will be the next thing to blow up.

I love doing my own work.  Lots of frustration but when you get it fixed it makes you very happy.  Gonna take the rest of the day off and do some domestic duties and will likely run the motor on the muffs tomorrow.  I have a few other things to do tomorrow so it looks like Wednesday will be the first opportunity to get the Ranger wet.

[BassmanRudy]

Yay!! Sure did look arced to me.

[Bud Kennedy]

I saw that too but not sure it was an arc but it could have been I guess.  There was not any arc marks on the washer and the board was hard to see with my own eye.  The camera seems to suggest that it did arc.

[J.W.]

Glad you got it sorted out. Electrical gremlins are the worst. Seems like when they pop up it's a game of "guess and check" or even worse, "guess and replace." Not fun.

[Oldfart9999]

Good deal Bud, it usually turns out to be something simple but can be hard to find.
Rodney

[Donald Garner]

Alright, glad you were able to get it fixed    Best of luck on the upcoming river trip.