Interesting electrical problem...possibly the ground???

[SS194]

Hello, I have an 76 Slickcraft with a Ford 302. I replaced all of my battery and starter cables a few days ago because they were all corroded and were in pretty bad shape. While I was in there, there were a few wires (not exactly sure what they are for) that were badly corroded and/or broken. So I replace all of these cables, power up the boat and hit the starter. The solenoid just clicks. So I reverse the positive and ground on the starter thinking I must have screwed that up. Now the starter engages when I turn the key, but the engine is turning over backwards. I let go of the starter, and the starter does not disengage, even after turning the key to off, it's still cranking. I have to hit the kill switch in order to stop the starter.

I have switched everything I can find just in case something was backwards, and that is not the problem. And for some reason, no matter which way I have the polarity on the starter, it still turns the engine in the wrong direction.

And sometimes I won't get any power at all to the boat. Then randomly, all the lights come on and the horn and pumps and blowers and stuff all work. When I try to start, that's when it goes crazy.

I'm thinking I have a ground problem. Instead of trying to trace a bad ground, can I just run a new ground?

Where do I even start?

Thanks,
Steve

 

[WillyBWright]

Re: Interesting electrical problem...possibly the ground???

Start by taking it to a shop before any more damage is done. .

 

[SS194]

Re: Interesting electrical problem...possibly the ground???

That's not very nice.

 

[WillyBWright]

Re: Interesting electrical problem...possibly the ground???

I'm not kidding. I recently worked on a boat that had a very simple problem, but the owner did everything wrong and turned replacing a stupid cracked lanyard fork into a thousand dollar job. He's lucky it didn't cost him the motor.

 

[SS194]

Re: Interesting electrical problem...possibly the ground???

Here's the thing, I got this boat out of the junk yard for $2000 with a brand new engine, a great trailer, and an outdrive that's in pretty good shape. I ran it all last summer without a glitch. I had a problem with the starter cables that would get pretty hot while cranking, so that's why I decided to replace the cables. If someone gets into this boat, I'm sure they will find tons of things they could replace. I enjoy working on things myself and do not mind a challenge. This is a very simple boat, and I'm sure with some patients and a tester, I'll be able to figure out what's going on.

I am learning though, this electrical system is not exactly like the cars I'm used to working on.

I'm only going to the shop as a last resort. I can only imagine how much I'd end up spending on labor at a shop.

 

[jimhen]

Re: Interesting electrical problem...possibly the ground???

it's your boat, but I'm inclined to go with Willy based on what you have said. I'm not a pro mechanic, just a guy like you and I do everythng myself cause I am poor cheap and stubborn.
If you are not sure of your polarity and how to figure that out on your own you may be better off getting help !
They arn't going to overhaul your boat if you just ask for help with the starter. It will be cheaper in the long run.
But if you have to ... the blak wires are negative and the red positive. trace the black to ground and dissassemble and clean the connections there is probably more than one.

 

[jimhen]

Re: Interesting electrical problem...possibly the ground???

Also don't power up again until you are sure your polarity is right !!!!

 

[Coors]

Re: Interesting electrical problem...possibly the ground???

You need an oem manual, so you can re-wire it correctly.

 

[Robj]

Re: Interesting electrical problem...possibly the ground???

OK, maybe I am missing something here, but how could you reverse the polarity on the starter?? The big red wire goes onto the big stud on the solenoid. A big black wire goes somewhere onto the engine as your ground. Quite simple, I think?? Check all your connections and grounds to make sure they are clean. If you are still having problems, then I have to agree with the others to take it to a shop. Hooking up wires where they are not meant to go can make an aweful mess of your electrical system.

Good luck and have a great day,

Rob.

 

[Windykid]

Re: Interesting electrical problem...possibly the ground???

OK, maybe I am missing something here, but how could you reverse the polarity on the starter??



Just switch your cables on the battery! Now everything is reversed.

 

[Robj]

Re: Interesting electrical problem...possibly the ground???

I realize that, but what is the logic. -ve is ground, why would one even consider switching the polarity?? Does not make sense to me. The problem will not be fixed by reversing polarity, it will probably do more damage.

Have a great day,

Rob.

 

[Windykid]

Re: Interesting electrical problem...possibly the ground???

Agree it does not fix the problem, I think thats what he did in the first place.

 

[Windykid]

Re: Interesting electrical problem...possibly the ground???

SS next time with battery disconnected, one cable at a time and mark connections.

 

[Haut Medoc]

Re: Interesting electrical problem...possibly the ground???

Hmmmm.....
Nice way to welcome a new member....
You guys are helpful......
SS194, the wiring is pretty simple on this......
Looking aft at the solenoid, there are four terminal posts.....
The large starboard side connection, (left) is for all red wires....
The large port side connection, (right) is for the single thick yellow wire that goes to the starter....
The two smaller terminals on the front.....
Starboard side -thin yellow.....
Port side-thin tan......
The starter is grounded to the block through the mounting bolts....
NOTE:
There should be no black wire connecting to it or the solenoid with the exception of the grounding cluster that mounts on the bracket that is connected to the back of the exhaust manifold, where the solenoid itself is mounted to........
Hope this helps.......
P.S., you should get yourself a Merc. manual #2, but in the meantime feel free to ask any questions you might have......
PSS.....
Make sure you press the red circuit breaker located on the shift plate to insure that it is not tripped.....
Welcome to iboats, btw.......​

 

[SS194]

Re: Interesting electrical problem...possibly the ground???

Haut....THANK YOU!!!

Basically I screwed up. I should have written down exactly what went where, but I didn't. I pulled all the cables off to go match them up at parts store. Came home, started running wires and got stumped on which wire went to the starter off the solenoid. My ground wire runs directly from the negative of the batt to the negative of the starter.

I know for a fact that I had the wiring correct the first time, but started second guessing myself once I had problems.

I had an MR2 that had some work done. One day I turn the batt on and the starter engaged and wouldn't stop until I pulled the key out. Also started having problems with ZERO power to anything, then all of a sudden everything was back.

Took it to a shop and it was a bad ground wire. That's it.

Same thing is happening to my boat. I'm sure some wire somewhere is either broken or corroded and me poking around broke what little connection it had.

Unfortunately I won't be home for another few days. I'll check back in and let you know what I find.

I really appreciate the help. I know I didn't do what windykid said to do, and that's exactly what I should have done, but I didn't. This isn't a huge deal and I'm not taking it to a mechanic who is going to do the same things that I can do. I just need some guidance.

Thanks for the help,
Steve

 

[Bt Doctur]

Re: Interesting electrical problem...possibly the ground???

Only other way to have a motor turn backwards is to install a reverse rotation starter in a standard engine.

 

[wire2]

Re: Interesting electrical problem...possibly the ground???

Wait a minute; there's no negative cable on a starter. The negative from the battery goes to a bolt on the engine block. The starter is grounded internally when bolted to the block. The positive (red) from the battery goes to the left large stud on the solenoid, the right large stud goes into the starter.

>My ground wire runs directly from the negative of the batt to the negative of the starter.

 

[SS194]

Re: Interesting electrical problem...possibly the ground???

Here's an update for you guys. I've been out of town a lot and just now finally got around to messing with the boat again. I found that the starter relay was welded closed, that's why I was having so many problems.

So, here's where I went wrong. I thought the mounting bolt for the starter was the positive, when that was obviously the ground for the block. That's probably what welded my starter relay closed.

I installed my $17 relay and she fired right up.

I learned my lesson, I'm just glad it was a $17 lesson.

Oh and the engine was rotating the correct way the entire time. I guess I just never realized that it's a counter rotating engine.

Whatever.

Thanks guys!

 

[jpgoodman23@msn.com]

Re: Interesting electrical problem...possibly the ground???

SS, on a slightly unrelated question, where was the kill switch for your motor? I can't find mine on a Mercruiser 898 (305).

 

[Coors]

Re: Interesting electrical problem...possibly the ground???

It just takes time to stand back and cool off.