1972 Evinrude Hydro Electric 100hp Green Shift Wire Getting Hot

jbuote

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No, you don't need to connect the battery...
​Sounds like they're WAY out of spec..
​On the 200K setting, a reading of 3.3 - 3.7 is actually 3,300 - 3,700 Ohms. a LOT higher than 5-6 Ohms
​Betting the 20K setting gives similar results. Maybe 2 decimal places.

​You should be on the 200 (not K) setting. If that maxes out, then there's too much resistance...
​Just confirming you put red probe on green wire at the knife connector under the hood. (You replaced with spade connectors), and the black on ground right?

​Looks like the Blue wire is out of spec too.. 3,100 - 3,400 Ohms...

​Do you have the old (not the used but guaranteed to work) solenoids out where you can test them on a bench? Red where wire goes in, and black to casing where it bolts in?
​Wonder what that would be on your old ones...

​Also try different ground spots with the black lead... I've had high resistance readings because of a bad ground too.. (dirty connectors, dirty surfaces where things bolt on etc...)
 
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So the ones currently in the unit are the 'neused guaranteed to work' ones I recently bought. I have tried 8 different points of contact on the engine as my ground and my red lead into the green with setting on the 200 ohm setting NOT the 200k and I am getting a consistent between 6.7-7.7 ......... I then tested the original original solenoids that are not in and put the red lead to the green wire(upper solenoid) and put the black lead on it's same outside casing and I get a 1.3 consistent reading. I then put the red lead on the blue wire(lower solenoid) and put the black lead on it's same outside casing and get a consistent 6.7 while on the 200 ohm setting also. Do you feel all 4 solenoids are BAD ? I am kinda leaning that way now.
 

jbuote

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Yeah... With those tests, it's more in line with what it should be, but still out of spec.
​Personally, I'd think they were bad too, but not being an expert, I'd be asking too..

​Hopefully one of the experienced folks will chime in, now that it sounds like you had a valid test, with valid results... lol
 
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I am currently waiting on brand new solenoids, both upper and lower. Hopefully this is the fix.I don't see what more I can do to the lower unit as I have now replaced....1. Water pump housing,cup, gasket,plate. 2. Impellar. 3. Exhaust gasket. 4. New wires and harness from the solenoids that run up thru to under the hood. 5. Lower units seals and o-rings.6. All new wires and ends inside the throttle box. 7. New gear selector switch. 8. New choke toggle. I will update in a few days.
 
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So I tested the USED solenoids last night again about 10 times and got a consistent 6.7on both green and blue. I then had the BRAND NEW solenoids delivered today and tested them before I put them in and got a consistent 6.7 on both so I decided to put them in and mount the lower unit back up, connected battery, put key in and turned it to the in position and crossed my fingers but sure enough within 90 seconds that throttle box diode was warm. I am at witts end and really bummed I do not know where to go from here. I have now replaced EVERYTHING in the lower unit and throttle box outside of replacing the ignition switch. Does anyone know where and what I do from here now to figure this out ??? Should I try turning it over with the muffs hooked up and see if it starts even tho the diode gets warm ? .......Could it be the rectifier ? powerpack ? Stator ? ...... Please help me get this thing on the water guys.
 

jbuote

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I don't know... I have to go back to this:
You've tried other solenoids with the same results which eliminates the solenoids.

Obviously you have a dead short somewhere in that green wire. Unfortunately it's up to you to find out exactly where that short is.

​As for:
Could it be the rectifier ? powerpack ? Stator ? ......
As far as I know, No... None of those.. Engine isn't even running yet and it gets hot..

​Here's a link to the start page of a manual online with info on the push button remote box... It's for 60hp and lower, but I think the control box would be the same..
​left page, right side starts the pushbutton control box (Evinrude Only)..
​(I could be wrong, so up to you if it looks the same as the remote you have... )
http://boatinfo.no/lib/evinrude/manu...rude.html#/298

​Describes using an Ammeter to test at least which side the short might be on... and other tests too.. .
 
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Been a couple days of more troubleshooting but I am back with more questions. Still no luck on the fix unfortunately. Here is what my buddy and I have figured out....There is NO short from the green and blue wire from the wires under the hood that run north and thru the engine and up to the throttle box. Every test there shows it is completing a circuit...... It is however only showing a short still from the wires that run down the lower unit and into the solenoids. This is what makes no sense, I have replaced EVERYTHING including new wires and harness, brand new solenoids and even 'newused guaranteed to work' solenoids and it is still reading a short once the lower unit is bolted together. Like I stated before if the lower unit is not bolted together it doesn't get hot which is so weird to me. There is nothing left to replace in the lower unit. The 2 solenoids are the only thing electrical down there. The only thing I can think of is the way the wires are crammed into that small space where the solenoids are or does that not matter ? Does ANYONE have any more ideas ??? I am at a complete standstill on what should do next.
 

jbuote

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There is NO short from the green and blue wire from the wires under the hood that run north and thru the engine and up to the throttle box. Every test there shows it is completing a circuit......
Unless I'm completely off my rocker, (which is possible.. LOL), This confuses me... Completing the circuit IS a short The difference is, completing the circuit via switch or something is what you want. A "short", is completing the circuit in a way you don't want..
​(Unless I misunderstood what you're saying.. lol)

​With knife connectors (and Battery) disconnected, put red probe on the power wire that feeds the shifter switch, and the black on the knife connecter (one at a time) for each Green and Blue respectively (Boat side of wires, not wires running to lower unit):
When in FWD, you should NOT have continuity (should have Infinite resistance, or O.L on meter) through shift switch on either the blue or the green.
​When in Neutral, you should have continuity on the Green wire ONLY. (No continuity on Blue)
​When in Reverse, you should have continuity on BOTH the Green and Blue wires.

​Next, to check for a short to ground on boat side:
​Put red probe on knife connector (boat side, not leading to lower unit, one at a time green and blue, make sure they're not touching any metal on the head or pan) black on ground in remote control box (or metal part of control box casing)
Should not have continuity on either under any circumstance (Fwd, Rev, Neutral). If you do, then there is a short in the boat side wires somewhere.

​Basically, Starting with the long run (knife connector to remote casing) if you find 0 ohms then follow the wire up to the remote to it's next connection point, (could be harness plug that connects boat to engine wires, a splice in the wire loom, or connection at a switch inside remote...) disconnect wire there, put red probe where you disconnected wire and test again from there. This makes it a shorter run of wire trying to isolate the issue. If you now have no continuity, then short is between the testing point you're on and the previous testing point.. (checking for cut insulation, exposed wire etc.. along the way..)

​Then test lower unit wires again, red on knife connectors leading to lower unit (one at a time green and blue)
​Black on ground (or lower unit casing if unbolted). Should have 5-6 Ohms (Possible 6.7, should confirm that's ok..) on EACH of the wires.
​If 0 ohms on a wire, then there's a short in that wire.

It is however only showing a short still from the wires that run down the lower unit and into the solenoids. This is what makes no sense, I have replaced EVERYTHING including new wires and harness, brand new solenoids and even 'newused guaranteed to work' solenoids and it is still reading a short once the lower unit is bolted together.
This sounds like you may be confusing a short, and what it's supposed to do... If you're saying you get 5-6 ohms continuity when bolted up, that's correct and normal, not a short.
​However, if you're seeing 0 ohms, then yes.. There's a short in the lower.. (Cut insulation, exposed wire contacting any metal of the lower unit or leg inside)

Like I stated before if the lower unit is not bolted together it doesn't get hot which is so weird to me. There is nothing left to replace in the lower unit. The 2 solenoids are the only thing electrical down there. The only thing I can think of is the way the wires are crammed into that small space where the solenoids are or does that not matter ? Does ANYONE have any more ideas ??? I am at a complete standstill on what should do next.
Think of it like this..
​The casing of the solenoid was your ground when you tested them on the bench.
​The casing is attached to the lower unit casing somehow..
The lower unit casing is bolted to the leg of the engine.
The leg is bolted to the power head.
​The main ground is attached to the power head.

​So, if lower unit is unbolted, you have broken the connection to ground and you will NOT have power flow. (It won't get hot).
​When lower unit is bolted up, you have completed the ground connection, so power can flow through wires, down to solenoid, through solenoid casing to lower unit casing, up leg, into power head, and to the main ground wire.. Circuit complete. (it CAN get hot if there's a short somewhere, and that doesn't necessarily mean the short is in the lower unit.)

​I suppose it's possible that even the new wires got pinched in the "Crammed space" and cut insulation or something causing a short, but that should show up in the above continuity tests..

​Not sure how else I can describe it, and honestly, not sure if this description will even help you..
​Maybe there's something in the link I gave in a previous post to the online manual that can help as well?

Again,
​I am NOT an expert on these, nor am I an expert on troubleshooting them, but I have one and that's the best attempt I have to describe it as I know it.
Hopefully I'll be corrected if anything stated above is incorrect...

​I truly hope that helps, but I'm out of Ideas and ways to describe it.

​For what it's worth...
 

F_R

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I quit reading this thread some time ago, but just now came back to see where it is going. If it were me, and I was concerned about the blocking diode temp, I would be checking the amperage through it. The expected amperage can be found by calculations, using Ohm's Law and a wiring diagram. If amperage is excessive, then it is up to you to figure out why. There are other items connected to that circuit besides the solenoids. But common sense combined with knowledge of electrical circuits is the key. And that is a fairly complex system on that motor. You need on-site help. Or you can flounder around in the dark and buy unneeded parts.
 
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The advise given above is solid!
Testing wires can be tricky. I would replace the wires as the wires can be broken inside of the insulation and not be seen and can test good when bent just right.
The wires are usually bent in the same location to facilitate installation and can cause internal breakage.
Again the advise already given is solid!
 

F_R

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I heard it as jack up the gas cap and run a new car under it. Then go down and buy a new gas cap.
 

F_R

Supreme Mariner
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Could be. I'm not that old. But I do remember some cars had cranks. And throttle & spark advance on the steering wheel. And suicide doors.
 
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Duely Noted fellas. I appreciate all the feedback. F_R, yes the diode heating up is the issue. That diode is not suppose to be getting hit let alone warm.....JBUOTE i really appreciate the time and respectful replies you have given me. I am going to forward those instructions to a friend(with more electrical know how) and have him perform those tests over the weekend................ That aside this is my UPDATE.....So after working on the boat today a little this what I did. I decided to try cranking over the engine(muffs and water connected obviously) It won't start and also the cables that attach to the battery get really warm within 30 seconds of trying to start the engine. I am wondering if the starter is fried, powerpack is fried, coil, something else fried ? Would any of these components be causing the short or surge to the diode and cables ? Anyone know how to test my power pack ? I tested the rectifier via instructions and it tested good so i know it is not that. Again I would like to say THANK YOU to everyone who has been trying to help, you guys are awesome 👍. I just want to be a happy boater asap
 
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jbuote

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if your battery (6 awg I think) are getting warm/hot while cranking the engine, then It's most definitely time to CLEAN all connection points in the starting circuit.
​Use wire brush if it'll get it all, but use sandpaper if you have to.,., You want those connections nice and shiny with no corrosion.
Also make sure there isn't any corrosion wicking up under the insulation on the battery cables.. That's common., Can go quite a ways up the cable if it's bad enough..

​Take off starter, clean the surfaces on the starter and the head where they contact each other..
​Take wires and cables off of starter solenoid and clean them up..
Take positive cable off starter and clean that up
​Also clean the ground points on the block...

​I particularly had an issue with the ground lug on mine..
(Blue box below. Pic is from another thing I did, but the ground lug is in there. At least where it is on my 50, but I'd guess it's something similar to this on your 100??)..
Safety Switch Testing.jpg

​I had to remove the whole bolt from the power head and clean it up.. Mine broke when taking it out, so had to drill and tap the head for a new one,
so be careful if you actually remove the stud from the engine..

​On the battery itself, again, shiny clean connections..
Use nuts and a wrench to secure cables to battery posts..
​No wingnuts or hand tight fasteners..

​Basically, if you look at a wire and think "Hmm.. Should I take that off and clean it?" Then the fact you thought it means the answer is a resounding YES!!
​Take it off and clean it! lol

​Doing the above will "Probably, and Most Likely" take care of the cables heating up when cranking (though not guaranteed...)

I'd consider taking pictures of the areas you work on BEFORE and AFTER cleaning them.
The before pics can help if you forget where things are connected.. Use the pics to reference where it was..
Also, get a hold of a wiring diagram for your engine.. Use that to be sure things are connected correctly..
​(Factory service manual specific to your engine is a virtual must!)

​Not sure if this will relate at all to (or help) the diode heating up... Don't think so, but I'm not looking at the diagram, so you never know.. Stranger things have happened, and it may help the diode problem at the same time... :noidea: (Common issue is they both heat up.. )
​lol
 
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Thank You Sir. I will in fact do that tomorrow. Do you know the symptoms of a bad powerpack or how I can test mine ? I disconnected it at plug yesterday and there's 5 wires that run into the plug harness. I will start attaching pics as well. Thanks
 

jbuote

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Some (but not all), symptoms of a bad power pack is no spark on a cyl, weak spark, loss of spark after warming up...
​Lots of things, but has to do with spark.. (usually.)

​To test the power pack, stator, etc... You need a multi-meter and a DVA Adapter,

Best not to jump the gun on anything for now.. Think about that stuff later.
​Just one thing at a time..

Right now, it's wires and such heating up..
​Solve that, then look at other things..

That's my approach anyway..
​Start at the beginning, test everything, find problem, Fix problem, repeat by starting at the beginning again until no more problems.. LOL

​It's uncanny how sometimes fixing 1 problem, can expose another issue in something you already checked before and seemed good! Or even fix another issue that seemed like it was something else...

​So when you think you're done, test it all again to be sure..
But ONE step at a time...
 
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