More Electrical Issues:(

[Dougal]

My list of ongoing problems get longer
My engine won't crank with only one battery. Solinoid clicks and lights dim. Just like a flat battery. If I add more current with another battery, all is well and starter turns engine well. All batteries are good and fully charged.
I've removed, inspected and cleaned all connections at battery end.
Can anyone think of anything remaining other than poor starter motor connections that could cause these symptoms? I ask as starter motor is an absolute bitch to get at.

 

[Champagne Murphy]

I had a similar problem last year. What I didn’t have was the strange thing with the different batteries which speaks of either a duff battery or a duff battery connection. Have you checked the fluid levels (if lead/acid). Then you could try fully charging them, then disconnect for 24 hrs and recheck the voltage. If one has fallen then its the problem. Also (and this is what I had to do in the end) disconnect all the joints, one by one, check them and run a file over both surfaces to ensure a good connection. I found a broken battery connector (although that wasn’t the problem) and just got so exasperated I did all the joints at one go. Cured the problem but I never did find out which joint was at fault.

PS I should have said that just because a battery gets to a good voltage doesn’t mean its accepted a full charge.

 

[PaulRainbow]

To be sure it isn't the battery, can you swap with another one ? Failing that it sounds like a bad connection on one of the main supply cables, rather than the solenoid energising wire. Make sure both battery connections are good, then look at the negative cable. it probably goes to the engine block, rather than the starter, this is often the source of problems with starters, alternators etc. Remove the cable, clean the terminal and where it bolts, apply some silicon grease and refit, apply more grease. After that, it really only leaves the positive connection at the starter. I am assuming you have a pre-engaged starter (solenoid built into starter), if not you'll also have to clean and grease any solenoid connections.

 

[zoidberg]

I'm sure some much more qualified than myself will contribute, but FWIW...

You have demonstrated that the starter device itself functions when supplied with enough 'wiggly amps'. You have demonstrated - you believe - that the batteries you have can supply sufficient power for the starter to function. I'd query the nature of the 'test' you've given them, for it may be that one of them is failing internally. Can they be taken off and 'stress tested' professionally?

Given a confirmatory answer, then the problem seems to be in the cabling and connections.... not carrying the required starting current when required.

Several possibilities suggest themselves: one or more of the connections is inadequate, due to surface corrosion or a vibrated-loose nut-on-terminal. The cabling itself may not be 'tinned' and corrosion could have developed on the surfaces of the multitude of tiny wires. There may not be enough 'sound' connection between the copper wires and the inside of a terminal. The 'calibre' of the cabling may not be of adequate cross-sectional area for the load, perhaps through some 'cracking' of a crimp-terminal, creating a large resistance. All that suggests to me a removal, inspection, test or/and replace.

A good marine 'lecky, armed with a good multimeter and some years of 'know how' ( there are several around here ) will be along and have some suggestions for elimination of some of the above......

Edit: Oh, I see one of them just has...... :encouragement:

 

[LadyInBed]

I had a similar problem a couple of years ago.
Taking out the starter motor and cleaning up all the connections sorted the problem.

 

[Pye_End]

It would be worth taking the battery voltage whilst turning the engine over. If it only drops a long way it is a battery issue. Sometimes checking battery voltage at rest doesn't give a full picture.

 

[lpdsn]

It would be worth taking the battery voltage whilst turning the engine over. If it only drops a long way it is a battery issue. Sometimes checking battery voltage at rest doesn't give a full picture.

+1

Those little LED digital voltmeters are cheap and accurate enough. Won't take the OP long to temporarily fit one across the battery terminals and lie it somewhere where he can see it when trying to start the engine.

 

[Dougal]

Thanks for help guys. I have 3 nearly new batteries. One normal 95ah for engine and two 105ah deep cycle for domestic. None of themy will engage the starter but any combination of two or more will. Also just fitted a new 1 2 or both switch as I thought that was faulty.

 

[lpdsn]

Thanks for help guys. I have 3 nearly new batteries. One normal 95ah for engine and two 105ah deep cycle for domestic. None of themy will engage the starter but any combination of two or more will. Also just fitted a new 1 2 or both switch as I thought that was faulty.

How big an engine do you have? A 55Ah starter battery has started my 4-cyl Yanmar without issue for the last nine years, so you should have no trouble at all with a new bigger battery unless it is duff (I'm ignoring CCA at the moment as I assume they are high enough).

Check the voltage when it is cranking and if it isn't duff the problem is elsewhere in the circuit.

I'll try not to comment on the 1-2-Both switch as it incites a lot of debate, but I do prefer to keep the starter battery for starting the engine and nothing else.

 

[Dougal]

Perkins 4.108 hence the beefy 95ah.
Know doubt I'll need to crawl from my primeval ooze and upgrade from the 1-2-both switch sometime, but yes, for now we'll leave that debate slone

 

[Dougal]

As all three of my batteries, when connected alone, aren't able to crank the motor, I'm going to asume it's not a battery issue.

 

[Dougal]

In the almost 10 years I've had this boat, I've never previously uncovered the main cable to the starter. It's still the ancient system of battery supply cable feeding separate solinoid on stb side of engine. The separate cable to the starter motor from solinoid is actually black but surely should be red?! I can just about reach all connections so will attempt removal, inspection and cleanup.

 

[seadog30]

Hi Dougal

Had a similar problem with my old Perky 4107, I pinched a solenoid out of our old clasic mini problem solved. went out and purchased a new solenoid problem returned !. The new solenoid (a far east lucas copy) was faulty out of the box !. Found a replacement in a car breaker. Problem solved.

Also check all connections and replace wires where possible, mine were all as supplied by the company who made bike lamps for Wollworths. Much reduced volts drop with new wire and connections.

Good luck

 

[zoidberg]

In the almost 10 years I've had this boat, I've never previously uncovered the main cable to the starter. It's still the ancient system of battery supply cable feeding separate solinoid on stb side of engine. The separate cable to the starter motor from solinoid is actually black but surely should be red?! I can just about reach all connections so will attempt removal, inspection and cleanup.

The colour of the insulation won't affect the electrical conductivity, but that suggests that maybe the original installation may not have been 'to the highest standards' as espoused in here. It may therefore have been made-up in untinned cable and, after 10+ years, is now showing you the symptoms of surface corrosion, which creeps into the crimp and up the wire, from any tiny entry point for moisture..... and thermic cycling will draw moisture in, slowly, over the seasons.

Removal of each of the cables for close inspection, for resistance testing and clean-up seems indicated.... and measurement of the distances run on each. Complete renewal, in the right Gauge of cabling, is not very expensive in materials. ASAP, and others, provide a reliable overnight courier service. I have the necessary hand hydraulic crimper here just south of Bath. You could pop along here ( Wiltshire ) and make up your new ones, while I brew the coffee.

 

[Dougal]

Would love to take you up on that, but both the boat snd myself are in Brittany until late September.

 

[Dougal]

Anyone got an old solenoid laying about?

 

[<152587>]

Two quick "roadside in the field checks"

1 Try and start the engine but lean on the start switch for say 5or 6 seconds. Are any of the connections getting hot in either the neg or pos lines?

2 Connect the dvm set to 20 volts, red lead to the incoming terminal of the solenoid, black lead to the outgoing terminal of the solenoid. Again try to start the engine, press button long enough to allow dvm stabalise. If the reading is zero the solenoid is functional, any voltage indicated on the meter will indicate a potential difference (voltage and current drop) across the solenoid contacts.

 

[superheat6k]

Assuming as you mention these are decent newish batteries, with sufficient Cold Cranking Amps capacity, this does sound like excessive voltage drop to the starter. Finding the root issue can be difficult and frustrating.

Also it is easy to overlook the negative return. I had this issue a couple of months ago, and the source of the problem only became apparent when I noticed smoke from the battery negative. The cable itself looked OK, but had become loose in the swage of its lug, oxidised and was then presenting a high resistance to the high current flow during the starter operation.

This is what I would do ...

1 Note the battery voltage at rest.

2 Measure the voltage when starting at various positions, with the engine battery only. Write these down in a table.

Negative at battery terminal lug of engine battery, then Positive at ...

Battery terminal lug; Cable itself at battery terminal lug; Solenoid from battery lug; cable; Solenoid to battery lug; cable; Starter lug; cable

Add to this list each and every joint on the cable runs.

Repeat these measurements for Negative at Battery cable by lug, starter terminal then again the cable at the lug. For each and every measurement make sure you have a clean connection.

The above requires 32 separate measurements.

2 Repeat for the second battery

3 Repeat for both together.

Now this is going to place a lot of start cycles on the starter so take the readings at 2 or 3 minute intervals, and keep each measurement as short as possible. After around 10 starts give the starter and battery a longer period of recovery.

Once you have your table look for notably lower voltages at the various reading positions. An analog meter I think gives a better visual presentation of the voltage dropping as the starter is operated. However, as you go through this exercise poor connections may become obvious.

For replacement cable Tri Rated 50 or 70mm2 cable, using a hydraulic crimper. City Electrical Factors supply Tri rated cable in the cut length required. Cable ties direct for the lugs, make sure you have the correct CSA and fixing holes sizes for each lug. A crimper from Ebay is ~£20

 

[LadyInBed]

Anyone got an old solenoid laying about?

If it works when you up the battery capacity then I would have thought it more likely to be a connection issue.

 

[PaulRainbow]

If it works when you up the battery capacity then I would have thought it more likely to be a connection issue.

Precisely.

An easy test for a dodgy solenoid is to short the two heavy cable terminals together.