3.0L 135hp merc starter problem but everything checks ok - stumped

[Skyrider1]

I have a nice running 3.0L in a Bayliner that is giving me starter problems. The key switch, solenoids, starter, engine and battery test good but will not start with key. I can jump the solenoid and the starter turns over the engine and the engine starts. Here is what I have checked. The key activates the slave solenoid. The slave solenoid activates the starter solenoid. I hear a click on the starter solenoid but it doesn?t put 12V to the starter post. The starter was repaired and all worked the first 1/2 of last year and quit half way through the year. We jumped the solinoid to start the last part of the year. I have replaced the starter solenoid...twice. I am stumped. What am I missing? Any help is appreciated.

 

[Don S]

Re: 3.0L 135hp merc starter problem but everything checks ok - stumped

Just hearing a click doesn't mean the solenoid is working, only that it's clicking.

HOW TO: Troubleshooting your engines starting system?/ 167035

 

[Skyrider1]

Re: 3.0L 135hp merc starter problem but everything checks ok - stumped

Just hearing a click doesn't mean the solenoid is working, only that it's clicking.

HOW TO: Troubleshooting your engines starting system*/ 167035

Thanks for the link. the tests show that the starter solinoid is bad but I have put two new ones on now with no change, just a click when I hit the key. I know the starter works cause I can jump it and I know Im getting 12V to the S post on the solinoid but no luck on either of the new ones I installed.

 

[Don S]

Re: 3.0L 135hp merc starter problem but everything checks ok - stumped

How about a SN for your engine.

 

[Don S]

Re: 3.0L 135hp merc starter problem but everything checks ok - stumped

Post a picture of your starter solenoid. You may have the wiring wrong.

Here is a newer procedure that may be easier to print out, and follow for the tests.

View attachment Troubleshooting a mercruiser Starting system rev2.pdf

 

[Skyrider1]

Re: 3.0L 135hp merc starter problem but everything checks ok - stumped

How about a SN for your engine.

Here is the serial number D501009

I have attached pictures of the both solinoids and starter.

 

[Skyrider1]

Re: 3.0L 135hp merc starter problem but everything checks ok - stumped

how about a sn for your engine.

d501009

 

[dubs283]

Re: 3.0L 135hp merc starter problem but everything checks ok - stumped

when you jump the starter solenoid are you energizing the primary (smaller) post??

have you tried troubleshooting the slave solenoid??

 

[SSTKO81]

Re: 3.0L 135hp merc starter problem but everything checks ok - stumped

Thanks for the link. the tests show that the starter solinoid is bad but I have put two new ones on now with no change, just a click when I hit the key. I know the starter works cause I can jump it and I know Im getting 12V to the S post on the solinoid but no luck on either of the new ones I installed.

I've had the same issue on mine at various time. Won't start with key, then it will, etc. The problem is the solenoid, almost certainly. It takes a beating and
A lot of heat back by the engine. That can cause internal expansion issues and will cause the solenoid to fail -if only intermittently. I invested in an expensive aftermarket one and haven't had a problem sinse. But I keep a old spare on board just in case.

 

[Bt Doctur]

Re: 3.0L 135hp merc starter problem but everything checks ok - stumped

If you apply 12v (jump) to the small pin on the starter mounted solenoid and the motor turns, thats good.Now folly the yellow/red wire back to the slave solenoid.The red/purple wire is what supplies the 12v .Check it for 12v.if not find out why.
short the 2 large lugs of the slave, motor should turn.
Next apply a 12v to the small yellow/red wire on the slave, motor should turn, if motor does not turn ,check the black wirs at the slave for a good ground.
If still having issues, run a tempory wire from the start position of the ign switch to the small lug of the slave. If it now works ,you have a corroded wire between the ign switch and the slave.

 

[Skyrider1]

Re: 3.0L 135hp merc starter problem but everything checks ok - stumped

when i jump the solinoid all I do is touch post to post. The small "S" post is not energized. the slave solenoid seems good to me. A test light lights up when I turn the key and touch it to the small post. It also then puts 12V to the "S" post of the primary solenoid so it seems to work.

 

[Skyrider1]

Re: 3.0L 135hp merc starter problem but everything checks ok - stumped

If you apply 12v (jump) to the small pin on the starter mounted solenoid and the motor turns, thats good.Now folly the yellow/red wire back to the slave solenoid.The red/purple wire is what supplies the 12v .Check it for 12v.if not find out why.
short the 2 large lugs of the slave, motor should turn.
Next apply a 12v to the small yellow/red wire on the slave, motor should turn, if motor does not turn ,check the black wirs at the slave for a good ground.
If still having issues, run a tempory wire from the start position of the ign switch to the small lug of the slave. If it now works ,you have a corroded wire between the ign switch and the slave.

If I apply 12V to the 'S" post of the primary solinoid it does not start. Only a click. That says to me it is bad so i replaced it last year and it didnt work and then I put on a new one again this year but it does not work. I dont understand the mechanics of what the plunger does but maybe there is something wrong there. As I mentioned the start works when I put 12V jumper cable to the start + post.