Engine will not crank over - intermittent condition

[deanries]

All - First of all I own a 1992 Maxum 1800SR with a 3.0L Mercruiser, Alpha One - Gen 2 drive. Have been dealing with this issue for over three seasons and the issue has gotten worse this past year. Three years ago the starter & slave/starter solenoid and it seems to work for some time. Had the issue come back the next year so I determined it had to be the starter switch. Well that was replaced and again, seemed to work as desired. Then the issue came up again this year and fault isolation seems to lead to the starter/slave solenoid which again was replaced. Again the issue was still there but still intermittent. Need someone to tell me what the issue is. Checking the neutral safety switch seems to operate as desired so do not think it is the issue (but could be?). All the electrical connections all seem to be clean & tight from the ignition switch to the starter/slave solenoid. Any suggestions?

[mmwjr]

Have you verified the battery connections are clean and tight including the negative connection to the block? Have you used a volt meter on the battery cable at the starter to see if the voltage drops when cranking? I have heard of battery switches going bad resulting in a voltage drop when cranking.

[deanries]

mmwjr - I have checked the electrical contacts / connections at the battery, on the engine block, the starter & starter slave solenoid. everything is clean and tight. The issue I get is there is a clicking sound but the starter does not crank over. Fault isolation states that the starter slave solenoid is the problem. That has been replaced two times now and the issue is still happens, but is intermittent. That is what has me dumbfounded. FYI - I am a 40+ year aircraft mechanic so I truly understand clean and tight electrical contacts. Plus I looked through the schematic for Mercruiser for the 3.0L engine for the start system. Missing something?
deanries (Go Big or Go Home)

[mmwjr]

Dean you can call me Mike. Lots of time the reason the soleniod clicks is due to low voltage. Have you measured the voltage at the starter when this occurs? As I mentioned I have heard of faulty battery switches that cause voltage drops.

Note if the voltage is good the soleniod would only click once and hold.

[yahoo82]

Mmwjr’s comment reminded me that I had a similar issue at the beginning of one season and it was the battery. It would measure 12V+ and the house loads worked fine, but I think due to improper storage it had some internal damage, so it couldn’t provide the full amps to the starter and the voltage drop was too high. Strange thing was I had expected a low voltage issue would crank SLOW and provide some feedback the battery was shot when it fact it either cranked or didn’t. It was made harder to troubleshoot because it depended how long the batt was charging on shore power, etc.


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[mmwjr]

Each cell of a wet battery produces 2V, there are 6 cells to produce a total of 12Vs. Just loosing one cell can prevent and engine for starting.

[deanries]

Mike & All - Guess I failed to mention that I did purchase a brand new marine battery at the start of the season last year. I have not measured for voltage drop at the starter but will check that possibility. I will also go through each connection point and again clean them thoroughly and tighten. Problem for me is it is an intermittent issue. Makes it tough to isolate the problem! For the starter slave solenoid it was one click which means it engaged (aka an electrical switch). Why the starter did not crank over has me confused? Keep working on it until I find the problem. Thanks for the help folks, most appreciated!
deanries (Go Big or Go Home)

[mmwjr]

Don’t rule out a faulty battery switch as the wiper arm may not be making good contact resulting in a voltage drop under load. The starter draws 100’s of amps as opposed to the running load of <= 50 amps.

[deanries]

Mike / All -
I only have one battery and do not have a battery switch. I have replaced the ignition switch since it directs power to the starter slave solenoid. That did not fix the intermittent condition/issue. Just hate electrical problems, can be so hard to find the culprit/fix!
deanries (Go Big or Go Home)

[mmwjr]

Originally Posted by deanries

Mike / All -
I only have one battery and do not have a battery switch. I have replaced the ignition switch since it directs power to the starter slave solenoid. That did not fix the intermittent condition/issue. Just hate electrical problems, can be so hard to find the culprit/fix!
deanries (Go Big or Go Home)

In this case the battery positive cable goes directly to the starter solenoid. When this intermittent issue occurs you’re saying the slave soleniod does one solid click and the starter solenoid chatters; correct?

[jody]

deanries, I have a 2003 1900 that i had a random no start as well. after changing the starter it was still there. i checked all of the connections and terminals. all were good. I cut back the insulation on the battery cable and found the wires were rusted/rotted. they "looked good when looking at them. made some new wires and all is good. Good looking does not always mean good.

[mmwjr]

Originally Posted by jody

deanries, I have a 2003 1900 that i had a random no start as well. after changing the starter it was still there. i checked all of the connections and terminals. all were good. I cut back the insulation on the battery cable and found the wires were rusted/rotted. they "looked good when looking at them. made some new wires and all is good. Good looking does not always mean good.

Good suggestion.

[deanries]

Mike / Jody / All -
The issue I get from the starter slave solenoid is one click, no chatter. Having been through this on my autos I know if it chatters it is usually low voltage/bad battery. Do not have that condition. Will check my battery cables, especially the positive one to the starter slave solenoid. Like I have said, hate intermittent electrical issues! They are a real pain in the ___. Plenty of time before the next season to find and correct the issue, hopefully!
deanries (Go Big or Go Home)

[jparsons121]

My money is on the slave solenoid gone bad. Contacts are worn out.
You can verify easily by checking for voltage on the post of the solenoid that leads to the starter. They are fairly cheap, and as I posted in another thread, one of those spares that I carry onboard since the same solenoid is used on the trim pumps as well.

[jody]

deanries, that is what i had too. and as a retired auto tech i went after the starter as well first . but ended up being the wires. no harm in checking them and (in my option) they are easy enough too make.

[deanries]

jparsons121 / jody / all -
Definitely will check every connection and all the wiring involved in the engine start system another time. The starter is only 3 seasons old so it should be OK (?). The slave solenoid was replaced at the start of the season last year but might be the problem (?). Right now it is in the low 30's here and no heat in the garage. Will wait until it warms up a little. Thanks for all the suggestions, most appreciated! Dean
deanries (Go Big or Go Home)

[deanries]

All- After surviving another winter in storage it was time to get her ready for the water. After spending some time this past Spring checking the wiring, contacts, battery and ignition switch no problems could be found. The engine cranked over and started for the de-winterization run so I felt confident that the slave solenoid replacement near the end of the previous season was the fix. Finally got to put the boat on the water on the first weekend in June. The boat started without issue so all was good. Well after cruising the Kaskaskia River for an hour or so we parked it at an island north of New Athens, IL to have some fun & lunch. Also had the new Rubber Dockie floating mat to get it's first use. When the time came to leave the engine again failed to crank. All the checks showed power to the starter but it would not crank over. The bottom line on this issue was the starter finally, completely failed and had to be replaced. All is good now with a new Sierra Marine starter installed. No more issues concerning the engine will not crank. A couple hundred bucks plus my labor to install it fixed the problem.

[mmwjr]

Glad to hear you finally found and corrected the issue.