mercruiser 3.7 starter issue

[trkr75]

ok here goes, I have a 1986 Sea Ray 270 Sundancer with the 3.7 mercruisers in it. One runs fine the other I believe will run fine once I get the starter problem figured out. Here is what is going on. When I turn the key to the start position it starts to crank. when I release the key back to run position it keeps cranking. I have replaced the key switch, the silanoid (sp) and had the starter rebuilt. Still the same problem. I have went as far as to run new wires from the switch to the silanoid. Same problem. I have unhooked all wires from the starter except power wire and jumped the post to engage the starter same problem. Is there any thing else I should try before just buying a new starter? Even with a rebuilt starter still having the same problem.

Thanks

 

[Bondo]

Re: mercruiser 3.7 starter issue

Is there any thing else I should try before just buying a new starter?

Ayuh,... What yer describing is a Solenoid Issue, it's hangin' up, Not the starter...

 

[Don S]

Re: mercruiser 3.7 starter issue

Are you sure you have the wiring right on the key switch, solenoid and starter?

Did this problem just suddenly happen, or was something worked on, then it started having problems?

 

[trkr75]

Re: mercruiser 3.7 starter issue

yes, wiring is correct, verified on other switch (twin engines) and also in manual. installed new switches, new solenoid, and rebuilt starter with new solenoid.

 

[trkr75]

Re: mercruiser 3.7 starter issue

Ayuh,... What yer describing is a Solenoid Issue, it's hangin' up, Not the starter...

this is the second new solenoid I have put on to fix this problem both new

 

[Don S]

Re: mercruiser 3.7 starter issue

Did this problem just suddenly happen, or was something worked on, then it started having problems?

 

[stonyloam]

Re: mercruiser 3.7 starter issue

I have unhooked all wires from the starter except power wire and jumped the post to engage the starter same problem.

Agree it sounds like the solenoid is staying energized. You jumpered from the large post to the solenoid post and it keeps cranking, right? The only way this could happen is if somehow you are getting electrical feedback to the solenoid coil. In other words when the starter is getting voltage it also is somehow making contact to the solenoid circuit keeping the solenoid engaged. You can check this by taking a voltmeter and putting it on the solenoid post and checking the voltage. Should be 0 with no contact, briefly engage the starter by jumpering it, should read battery voltage, remove the jumper,the solenoid voltage should return to 0, if not and it keeps cranking you have a problem with the internal wiring of the starter. I think LOL good luck.

 

[Don S]

Re: mercruiser 3.7 starter issue

Personally, I keep wondering when he says solenoid if he means the solenoid on the starter or the slave solenoid..
If the slave solenoid is the wrong type, it may stay energized.

It's also why I asked a couple of times when it started and if some work was being done on it.

 

[stonyloam]

Re: mercruiser 3.7 starter issue

The way he described it is that he only has the heavy battery + cable attached. Hope to get more info.

 

[trkr75]

Re: mercruiser 3.7 starter issue

ok sorry for the delay, work in the day school at night. the solenoid (slave) I have tested by switching it with the other motor, works fine. there are two one little one and the one on the starter. The last test I did was to remove all the wires except the battery (+) and jump the solenoid, it kept cranking after I removed the "jumper" and kept going until I removed the battery cable. I have the starter out of the boat and am going to try it by itself tonight before I go to bed. it seems to me that it is a bad solenoid on the starter since I took everything else out of the equation. well let you know the results of the test soon

 

[trkr75]

Re: mercruiser 3.7 starter issue

to my frustration when testing out of the boat (jumper cables then shorting the solenoid) it works fine. yet in the boat did the same thing it keeps cranking. Could it be as simple as a ground somewhere on the motor not being hooked up for something else. I am at my wits end we have traced all the wires back to the switch and they are fine, replaced switch and checked, double and triple checked to make sure it is wired correctly. replaced the slave solenoid twice, and had the starter rebuilt. I am at a loss trying to figure it out. Maybe one of you guys can point something out, the problem is probably right out in the open I just can't see it. My father is coming down this weekend was hoping to take him out for a ride (still will, 2 engines remember) maybe he will figure it out. He was always good at things like this. oh well got to go to work, will try to think this through today

 

[stonyloam]

Re: mercruiser 3.7 starter issue

There are only two things that I can think of 1: The solenoid sticks after it engages and does not release, or 2: There is a internal electrical problem that is feeding voltage back to the solenoid. Check to see if there is still voltage on the solenoid terminal after you remove the jumper and the starter is continuing to spin.

 

[Don S]

Re: mercruiser 3.7 starter issue

Have you swapped starters port and starboard?? If not give it a try.

The fact that we aren't there, can't see everything you can, can't hear anything, makes it a huge disadvantage for us. I know I use sight and sound a lot in troubleshooting.

 

[trkr75]

Re: mercruiser 3.7 starter issue

that is the only thing I have not done is switch the starters side to side, will try that on Fri.

 

[djd999]

Re: mercruiser 3.7 starter issue

IM having the same problem on my 87 mercruiser 3.7. Did u find the answer to the problem?

 

[Don S]

Re: mercruiser 3.7 starter issue

Welcome to iboats djd999, if you are having a problem, best to just start a new thread of your own. Your problem my not be what caused the original posters problem.