Click but won't turn over

[dridas]

2006 Tahoe Q6S with a 5.0L MerCruiser Serial - 0W380250
I followed this thread for troubleshooting - and everything seemed to be right. I verified the Safety/kill switch were closed/shorted, and that the Neutral Safety switch was closed when in the neutral position. Verified power to the slave solenoid. Verified power was at (starter) terminal B when the Ignition was turned to the "start" position. I checked for voltage at (Starter) Terminal A as well, and power off the back of the fuse block seemed intermittent. Power was present with and without key in start position.

As for the fuse block on the starter, there was some slight surface corrosion which might have accounted for the intermittent contact, and I did not remove the block to verify. Haven't ruled it out, but it seems if power is present throughout the system to the starter solenoid, the problem might be a fuse that isn't completely blown?

Somebody mentioned jumping the two large contacts on the slave solenoid and that would make the starter spin, but I've verified that the slave solenoid is working. Power in, no power out with key in run position - power in, power out with it in the "start" position. That leads me to believe that the slave solenoid is working correctly. Perhaps he meant to jump the two large contacts on the starter?

I think I've followed the troubleshooting in the below link fairly well, although was confused by terminal B on the starter, and how the directions state to troubleshoot it. If there is power on that terminal with the key in the "run" position, it would indicate an issue somewhere else, since I believe that terminal is was pushes the drive of the starter to the crankcase. Power should only be there when the key is turned to the "start" position. Terminal D and C should be ground? Likewise, a bad ground on the starter would keep it from spinning, and a bad ground on the solenoid would keep it from pushing the star drive?

Anyhow, any assistance would be appreciated. I'm tending to believe the problem is either the starter itself or the white fuse block on the starter. I've stopped short today on removing the starter - that might be a weekend project, since it's in a tight spot - or I'd have to remove the starboard manifold to make it slightly easier.

 

[Bt Doctur]

Your missing the point. 2 things are needed to make an electrical item respond a 12v input and a current input. Reading voltage and not passing current will not make something work. If there is power at the red or red/purple post on the slave and you read 12v on the yellow/red the contacts may be making such a poor connection you will see voltage but cannot pass the current need to operate the starters solenoid.
The best testing is done with a load. I sometimes use a car headlight or a halogen bulb to draw amps. Could care less is it has volts.
Be like trying to start your motor with a 12 transistor battery or 8 D cell flashlight batteries in series

 

[Bt Doctur]

jump the 2 large lugs on the slave, starter spins or it dosent
With a jumper from the battery touch the large yellow/red wire on the slave , starter should turn
If nothing happens check the battery cable connection especially the engine neg one.

 

[dridas]

Your missing the point. 2 things are needed to make an electrical item respond a 12v input and a current input. Reading voltage and not passing current will not make something work. If there is power at the red or red/purple post on the slave and you read 12v on the yellow/red the contacts may be making such a poor connection you will see voltage but cannot pass the current need to operate the starters solenoid.
The best testing is done with a load. I sometimes use a car headlight or a halogen bulb to draw amps. Could care less is it has volts.

Bt Doctur - You make a very good point, and it's highly possible that the connection is bad enough that it'll light up my test probe, and not the starter. Test probe will work on as little as 6v. I have a 2 halogen fog light set up that I use for draining batteries to desulficate (spelling?). I'll check that out tomorrow afternoon. Thanks for the correction.

 

[Rick Stephens]

If twas me, I would take apart all the connections and wire brush them bright and shiny, paying particular attention to the battery ground side. All it takes is a tiny bit of electrolysis in a connection to make it fail under high amp requirements.

 

[Bondo]

If twas me, I would take apart all the connections and wire brush them bright and shiny, paying particular attention to the battery ground side. All it takes is a tiny bit of electrolysis in a connection to make it fail under high amp requirements.

Ayuh,.... A film of corrosion ya can't even see, will stop the electrons,....

I slather grease on cleaned connections to keep 'em corrosion free,....
Or, sprayin' 'em with Fluid Film,....

 

[dridas]

jump the 2 large lugs on the slave, starter spins or it dosent
With a jumper from the battery touch the large yellow/red wire on the slave , starter should turn
If nothing happens check the battery cable connection especially the engine neg one.

I jumped the slave solenoid and it sparked when I put it on the hot side. Attempted to turn the key, and heard a click (as I had before) and still didn't turn over. I'll do the jumper on the yellow/red tomorrow. Have to get some other stuff done this evening, and will try to do that first thing in the AM. Thanks for the advice.

 

[dridas]

If twas me, I would take apart all the connections and wire brush them bright and shiny, paying particular attention to the battery ground side. All it takes is a tiny bit of electrolysis in a connection to make it fail under high amp requirements.

I'll do that tomorrow morning. I have a feeling that I'm going to end up dropping the starter anyways, and might as well plan on cleaning that stuff tomorrow. It's a tight spot, and think I might use a dremel with a bristle brush. I'm assuming that the grease you speak of is dielectric grease? Or is there another type that would be better for Marine applications.

 

[dridas]

Thanks for all the advice and guidance. Great News - She starts and purrs' like a kitten. Not bad for sitting winterized for 2 years. Yeah, I know - really bad idea.

I can't name the culprit, but ended up changing-

New Starter
New 90A fuse block that sits on the starter
New Slave Solenoid
New 50A Circuit Breaker
Sanded every terminal lug, and "slathered" every connection with Dielectric Grease
Charged Battery, load tested, and analyzed. CCA's were a little low, but a little maintenance on a maintenance free battery never hurts. Just wear proper protective gear.

Anyhow, I never use fuel that contains ethanol, and have always added fuel stabilizer. Next up- warm up the oil, and change it for a second time.

Once again, thanks for the assistance, she is running like a dream!