Intermittent Cranking Issue

[sanibel sailor]

I have a cranking problem that is driving me nuts.

When it cranks, it spins merrily. starts right up and runs great. Seems to have an intermittent cranking issue. Other times, I get a resounding "clack" out of the solenoid and volts drop slightly, but no crank.

Just installed a completely rebuilt 4.108 in a boat that had set for a few years. Starter was rebuilt and a new solenoid put in. House battery bank (4 golf cart 6V's) is only a couple of months old, and initially had an older start battery, but started 5/24 after charging it. Started several times in a row. Overnight, it would not start in AM, even with good voltage showing. I recharged battery, rewired new hot lead to start switch from terminal block, still no go, so I put in new start battery. No luck. Batteries are fully charged, reading 13 plus volts.
This AM I cleaned all terminals of house and start batteries, cleaned all lugs at the battery switches, on the alternator hot wire and the battery isolator as well as the ground wires to the block. Fired right up, I am thinking problem solved, then later no cranking. So, I assume not enough volts to solenoid, I replaced starter switch, tried a wire direct from distrib panel to switch. No luck, only a click from solenoid.

I jumped a wire from the battery terminal on the solenoid to the switch terminal on it, just a loud click and a hot wire, but no cranking. Wire from terminal on battery selector switch same result.

Tomorrow I will take my little jump-start battery pack and try hooking that to it.

I am thinking that either my starter or solenoid is bad, in spite of being new or rebuilt. One item of significance is that a bad starter or solenoid is the responsibility of the engine guy, any other problem is on me. This started as a cheap and simple running take out swap and ballooned into a total rebuild. They have more hours in it than planned and I am over budget, so I am inclined to try everything before potentially running up my bill higher or asking them for more unpaid effort. Their shop is an hoiur away so a quick "drop by and check" is challenging. Yes, we are still on good terms and they are willing to check it again if I cannot figure it out.

Anything else to look at before I blame the starter or solenoid?

[ShipShape]

The starter that came with my boat ('95 Yanmar) had the same issue, sometimes it would start, sometimes just a click from the solenoid. Three years ago my last husband burned out that starter and solenoid so I purchased a NEW (not rebuilt) starter and solenoid ... same problem right out of the box!! I found that if I repeatedly turned the key on and off that it would start after five or ten times. I jumped it before I figured out I could get it going by turning the key on and off, but unlike yours, both started immediately every time.

[model 10]

After the solinoid fires and the drive engages the contacts for the starter motor are supposd to close then send power to the brushes, that ain't happening

[FlyingCloud1937]

Almost all starter motor issues are ground related.

A starter has 2 circuits, Primary and Control.

The best circuits have Isolated Ground for the Primary, the big wires to the bat & SW.

And, the solenoid also has an isolated ground, the Control, the small wires to to key SW. & Ground

Many starters have a ground through the block for the Primary and the Control, non-isolated.

Intermittent issues can be either the Primary or the Control.

So the first remedy is to replace the solenoid...wow it works with a new solenoid, so it must have been the solenoid. When really what likely happened is a good ground was made by unbolting and bolting on a new solenoid.

Or second scenario, I replaced the solenoid but it still doesn't work, so it must be the starter. Now you replace the starter, and everything works. If the starter doesn't bench test as bad then it was the ground again.

The proper way to trouble shoot is hook the pos side of your DMM to the pos side of the bat. now have someone crank the starter while you probe the neg side of the solenoid and the starter. If they aren't isolated then you have to probe the cases.

Lloyd

[model 10]

Lloyd; speak english. Your last paragraph is to vague for some of us.

[Cowboy Sailer]

I think that he is saying that a positive voltage at what should be a grounded point, either the negative side of the solenoid or the starter case indicates a poor ground.

[oldtomcat]

Make sure that the engine itself is grounded.


OTC

[sailorchic34]

Could also be corrosion of the high amp contacts in the solenoid. To check use a BIG straight blade screwdriver and short across the cables behind the solenoid. If the starter spins its the solenoid. If not probably brushes in the starter. Best NOT to ground between the contacts and the case btw...

Many times the contacts in the solenoids can be rotated 180 degrees. Some people have even fabricated new contacts out of 1/2" copper pipe flatted in a vice.

I've also had it be corrosion in the start wire from the push button to the solenoid, one time. That you can check by connecting a wire from the + side of the solenoid to the connection from the start button (a white wire sometimes). With care a screwdriver can work there too.

[FlyingCloud1937]

Originally Posted by Guy

Lloyd; speak english. Your last paragraph is to vague for some of us.

It is english, It's how you measure voltage drop in the ground wire.

Lloyd

[goboatingnow]

Sailor chic has it right , test it ( carefully )


Dave

[noelex 77]

It is most likely an electrical problem, but don't completely dismiss the possibility of hydro lock.
If it fails to start see if you can turn the engine over by hand.

[sanibel sailor]

intermittent hydrolock? seems unlikely, but I will try hand turning
doubt corrosion as only 4 days post install, I cleaned terminals of both big and small wire to solenoid.
I will check resistance between starter and ground cable but seems not to explain intermittent nature of problem.

[sanibel sailor]

No crank this am
Booster battery pack attached direct to starter and ground cable on engine and it cranked fine, disconnected and no go

Problem is most likely not in starter or solenoid, nor in the switch wire but somewhere in my battery system.

Later I will recheck, sequentially moving cables upstream to find problem spot. First step will be to isolate to either pos or neg side by hooking black to battery

Two suspects, my battery selector switches may have corroded contacts even though they look fine from the outside. Also there is a big shunt on the ground side for the Link monitor that I did not clean yet.

[sanibel sailor]

Still driving me nuts.

Tried further testing with booster battery which yields frustratingly inconsistent results due to the fact that it starts sometimes without the boost.

I have switched battery switches back and forth bunches of times to clean contacts, seemed fixed, but then not. Today I disassembled and cleaned the neg shunt connections. I will let it "rest" overnight and check its attitude tomorrow.

As far as I can tell, I have good solid clean contacts from fully charged batteries to the starter and the same on all the ground wires.

I am back to thinking it may be a bad solenoid. A few times when I jumped a wire from the battery post to the little switch wire on the solenoid, it did not turn. Just using a small gauge wire, so may be poor contacts, but still...

Can I pull the solenoid with the starter in place? Access is great. I understand it is a basic late 60's GM solenoid. Can anyone confirm this? Thanks

[oldtomcat]

You might have a flat spot on the starter. I drove English cars 60 years ago and they were prone yo developing flat spots. They even had a place to put a wrench to turn the starter off the flat spot and try in again.(Lucas electrics)( Charles Lucas was the prince of darkness).

Could Also be a brsh hanging now and then.

Just thoughts

OTC