1988 4.3 ltr engine starter wiring

[nola mike]

To spin the motor, disconnect the one wire going from solenoid to electric motor - says 'Field Lug' in your diagram, and just power that lug or wire that comes out of said electric motor.

I think you're saying just power the field coil lug directly, but does it matter? If 12v is getting to the solenoid and the Bendix is engaging, then either the solenoid is bad or the motor is bad. Either way starter needs to come out unless I'm missing something.

 

[Rick Stephens]

I think you're saying just power the field coil lug directly, but does it matter? If 12v is getting to the solenoid and the Bendix is engaging, then either the solenoid is bad or the motor is bad. Either way starter needs to come out unless I'm missing something.

However, that is not what he asked.

 

[Rivergator]

I fired my 4.3L up sitting on blocks of wood and with a 1 gal gas can, a garden hose to the thermostat housing, and a battery with jumpers. It is so easy as to be ridiculously simple. And is so much better than checking your work after it's in the boat. In fact the reason I mentioned it, still may be most useful to pull the motor and do that with yours.

To spin the motor, disconnect the one wire going from solenoid to electric motor - says 'Field Lug' in your diagram, and just power that lug or wire that comes out of said electric motor.

Well Rick, as you can see, this is my first time doing anything on a Mercruiser. My previous boat had a Volvo Penta drive train. So everything I do is a learning process and trial and error to see what works best for my situation, which is primarily the restrictions and obstacles of the boat itself. I thought it was easier to put the engine back in the boat, hook up the harness and start testing, starting with cranking the engine to see if I have oil pressure, all the electricals are working, then installing the exhaust manifolds (because it is very difficult to install the engine with them already on the engine). So I test everything step by step until I come to the last step and check the ignition. If I have spark I will put the manifolds on, hook up the water hose to the bell housing, turn the ignition key and see if she rips. Sure, I anticipated some problems along the way, but nothing that warrants pulling the engine again. However, I wholeheartedly agree with you I could have checked the starter easily while it was out and saved myself this aggravation. But since it was a brand new starter it never worried me. I learned the hard way, thanks to Murphy.

You can do anything if you spend the time reading up and understanding it. And don't mind getting dirty.

Rick, that's me. I am constantly reading up on everything and learning being on Iboats forum picking y'alls brains and I sure don't mind getting dirty doing it.
Well anyway, Kenny Nunez gave me a great trick to try which could make it rather easy to remove the starter while in the boat. If that doesn't work I will have to pull the engine at least a little bit. That's just the way my bilge is, very tight tolerances. It's not a big deal at this stage, just a pain in the butt.

 

[Rivergator]

I think you're saying just power the field coil lug directly, but does it matter? If 12v is getting to the solenoid and the Bendix is engaging, then either the solenoid is bad or the motor is bad. Either way starter needs to come out unless I'm missing something.

Nola, in essence you are right. I had that gut feeling too, but was looking for a miracle. By making sure that the starter spins but not engage I would be assured that the starter works. By making sure that the pinion gear engages without spinning I would be assured that the solenoid works, but then what is the problem? Could it be with the flywheel? Wrong tooth count on the pinion? Probably not. In either case the motor has to come out again. The tests that I did certainly point to the starter. The starter is dead. I removed all wires from it just to make sure there is no external interference. Then I put 12V+ to the field post (bottom post) nothing, I applied 12V+ to the switch post/blade (right post) nothing. I made sure starter has good ground. It does. So the only thing left is putting the starter on the bench and get to the bottom of it. If it works on the bench then I will have other problems to deal with. And the engine is not frozen. I can turn it by hand.

 

[nola mike]

By making sure that the pinion gear engages without spinning I would be assured that the solenoid works, but then what is the problem?

No, solenoid can still be bad. It has 2 functions, first to engage Bendix and second to connect the battery voltage to the windings.

 

[Rivergator]

No, solenoid can still be bad. It has 2 functions, first to engage Bendix and second to connect the battery voltage to the windings.

Thanks Nola for mentioning that. I will know when that bugger in on my bench. I am really dying to find out what the problem with this thing is. It kinda surprises me that I have a problem because the starter is brand new. I got it over a year ago, installed it on the engine 4 months ago and a week ago cranked it for the first time. I know I should have checked it when I got it. My stupidity.

 

[havoc_squad]

Thanks Nola for mentioning that. I will know when that bugger in on my bench. I am really dying to find out what the problem with this thing is. It kinda surprises me that I have a problem because the starter is brand new. I got it over a year ago, installed it on the engine 4 months ago and a week ago cranked it for the first time. I know I should have checked it when I got it. My stupidity.

I hope you are aware that quality assurance on parts made across the auto and marine industry is at an all new low.

Usually its aftermarket parts but some is OEM at fault.

Many independent and dealership service facilities have frequent complaints about new parts bad on arrival or fail within a very short time.

Usually its parts that have been remanufactured poorly.

Yours could be a defective paperweight.

 

[Rivergator]

Ok, the starter is on my bench and it is deader than a door knob. Strange thing is that both the starter and the solenoid don't utter a peep. If one would work and not the other I could understand, but both. And I made sure I had voltage, good ground and some. Could I have blown the starter the first time I turned the ignition key? If yes, how? I did one thing though. When I first turned the key I heard a click, but that was it. So I thought that I may have a problem with the slave solenoid. I quickly bridged the 2 top posts on the slave to see if that made a difference. It didn't. Now that the beast is on the bench I thought I will open it up to see what the problem is, but since it is a Marine starter (J1171) it is thoroughly sealed and on top of that, the main part that I wanted to see, the brushes, is totally inaccessible because I noticed a couple of spot welds on the back plate seam. So if you pull the armature out through the front, the brushes will collapse behind it and you are done. Yeah, I could have ground off the welds and remove the back plate, maybe some other time. So I gave up on it and put it on the shelf. Somethings in there I will be able to use in the future I am sure.
Now to the nice trick how to remove the starter fairly easy from the engine while in the boat. Kenny Nunez told me and it worked like a charm. I lifted the front of the engine just enough to take the weight off the front motor mounts and supported the engine with a couple of 2X4s. Then I removed the starboard motor mount inclusive the bracket and now I had all the fightin' room I needed. Within an hour the starter was out. But I don't think the trick will work too well if the exhausts are on the boat. Mine weren't.

 

[Rivergator]

Well, what can I say that Forrest Gump hasn't said already "Stupid is what stupid does". The reason why I am even posting this here is not to put myself down, no that's not it. To me it is nothing more than Murphy's law at it's best and I am just laughing about it and consider the whole dumb exercise a learning process and fun while doing it. I am posting this so others will benefit from it as well. Thanks to Kenny Nunez' trick I got the starter out of the boat with relative ease in less than an hour. I put it on my bench, pulled up the battery, which I knew was fully charged and kicked like a mule because I had it on my F150 for a day and it started my truck like a pistol. I put the butterfly nut adapters back on, because that is how the engine is connected to the battery, put on the jumper cables, measured voltage at the end of the jumpers 12.45 VDC and I didn't see anything wrong with that. Tested the starter, nothing. Big fat nothing. Ok, that proves once and for all my starter is definitely kaput. Get a new starter. In the meantime while waiting for this thing it is a good time to do my lawn mowing. I jump on my Ariens riding lawn tractor, turn the key, nothing. Ok, dead battery, not unusual, let me just reach for my boat battery's jumpers and jump start this thing. I turned the key, nothing. Not a click. That can't be. Now I went to full battle stations. I double checked the jumpers to make sure they had a good connection and it looked ok. They still measured 12.45 VDC. I was stunned. Now I had myself 2 beers to clear my head and sort it all out and came up with the idea to pull up my F150 and use its battery to test my starter. And my oh my, did this thing kick over. It almost jumped off my bench. Now I pretty much knew what the problem had to be. I took off the 2 butterfly adapters again, cleaned them up and wire brushed them thoroughly, did the same to the battery posts, put some dialectic grease on it all and tested my starter again and boy did that thing kick. Besides calling myself a moron I knew my problem was solved. Starter was fine. it was a simple case of corrosion and boy do I feel like a fool. All of this done for nothing. But after a few more beers I already felt better. Starter is already back in the boat, starboard front engine mount and bracket back installed, on to do the alignment procedure once I get my new alignment tool. As always, thanks for all the valuable advise. Without you all things would be a lot worse, believe me.