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-   -   Engine start shuts off chartplotter (http://www.sailnet.com/forums/electrical-systems/117610-engine-start-shuts-off-chartplotter.html)

Gladrags1 01-17-2014 08:05 AM

Engine start shuts off chartplotter
 
When I start my engine (Yanmar 4JH-TE) my chartplotter turns off and I have to restart it. I believe that this occurs because the electrical draw of the starter is so great at the instant that it engages that the sensitive electronics of the chartplotter lose needed power. I don't notice any other problems with other instruments but I can't say that with 100% certainty.

I only have 1 battery bank and no separate starting battery. The bank is big; 3 D-cell gel batteries with about 500 amps of reserve power, connected in parallel. The chartplotter is on the circuit with other electronics (ie: depth sounder, knot log). The VHF is on a separate circuit. Something just doesn't seem right with this.

I would like to add a starting battery but not sure the best way to wire this up or where to place it. That however, is another discussion. Would that solve my problem though or is there something else that is going on that this is a symptom of?

One thing I am suspicious about is the engine block ground. The bolt that screws into the block for the ground is loose (there is a little play in it) and was JB Welded in place. I'm wondering if I should remove that ground wire and attach elsewhere on the engine? If so, where? Ideas?

newhaul 01-17-2014 08:43 AM

Re: Engine start shuts off chartplotter
 
Sounds like the starter is intact drawing lots of extra power and yes fix the ground on the motor BTW job weld is a verry poor conductor of electrical current. Any time you have poor connections it takes extra power to overcome that just like corroded connections. Also there are several threads on here that have addressed the addition of a starting battery complete with scamatics I'm on way out for weekend do a search for wireing solar or adding installed chargers. Hope this helps

eherlihy 01-17-2014 10:05 AM

Re: Engine start shuts off chartplotter
 
Engaging the starter is pulling the voltage available to the instrument circuit below what is needed to keep the chartplotter on. I suspect that you may not have a fuse on your battery bank either....

Is this a new symptom, or has this come about suddenly?

Where to start:

Fix the ground to the engine block. I suggest adding a negative bus bar, and connecting everything to that.
Inspect the cables that run to the battery bank for corrosion, both at the connectors, and in the cables themselves.
How healthy are the batteries in the bank? Have you had them load tested? ( )

redline 01-17-2014 10:25 AM

Re: Engine start shuts off chartplotter
 
First, definitely clean up and fix that ground. I had a poor ground on the engine block which almost caused a fire as it heated up and melted the insulation on another wire passing beside it, besides having spent considerable time debugging a non-charging alternator (it can be confusing when the alternator +ve output is correct, but its -ve terminal is actually a couple of volts above "chassis ground", to which all measurements were referenced, hence very little current flow.)

A separate starting battery is best; even with a good battery I had to move my Link2000 battery monitor power source to the house bank (3 group 27) because it would often register a "low battery" alarm when starting my 4JH2-TE.

Another approach bif you really can't fit a starting battery is what a friend did on his boat: to prevent his VHF from resetting when when cranking his engine, he added a small gel-cell alarm-type battery with a blocking diode from "ship's battery" to the backup battery, then to the radio. It does incur a half-volt (0.7v for purists, less if he used a Schottkey diode, I didn't ask) drop but the radio now stays on while cranking. Plus it give him a bit of "emergency power" for the VHF to call for a tow if he flattens his main bank while attempting to start, at least theoretically.

The simplest thing would probably be for you to split your paralleled 3-battery bank into two; one for starting and the remaining two for a house bank. You'd only need a minimal amount of cabling to separate the panel and engine feeds and to add a battery combiner relay or similar (ACR) for charging. You'd have a smaller house bank but avoid the need to find or create space for another starting battery.

I'd also double-check the power connections to the chartplotter, maybe it's only getting marginal voltage to begin with.

As another poster wrote, load-testing the batteries would be a good idea - the 4JH is a big engine, but that's a big battery bank.

Good luck.

Gladrags1 01-17-2014 01:54 PM

Re: Engine start shuts off chartplotter
 
Quote:

Originally Posted by eherlihy (Post 1316802)
Is this a new symptom, or has this come about suddenly?

Where to start:

Fix the ground to the engine block. I suggest adding a negative bus bar, and connecting everything to that.
Inspect the cables that run to the battery bank for corrosion, both at the connectors, and in the cables themselves.
How healthy are the batteries in the bank? Have you had them load tested? (Load testing - Wikipedia, the free encyclopedia)

This is not a new symptom. I have checked for corrosion at the batteries but will address that ground. The batteries have been load tested and while they are not new, they are in good shape.

I would like to move that ground to another spot on the engine. Any suggestions? Can it go on the alternator bracket as long as it is securely bolted to the engine?

Tod

Steve523 01-18-2014 01:46 AM

Re: Engine start shuts off chartplotter
 
Darn I just spent so long telling you how to check this, I lost the whole message when I tried to send because I was automatically logged out. Private message me and I will try again later. You can put a ground anywhere that the hardware penetrates the block and your terminal fits. Other places are iffy.

hellosailor 01-18-2014 09:53 AM

Re: Engine start shuts off chartplotter
 
No need for a starting battery if you clean up the existing problems, mainly putting in a good ground point and getting rid of the JB Weld kludge job. You might also take a good look at cable sizing and condition, make sure the battery cables (hot and ground) are adequately sized and not corroded anywhere.

It is pretty common to put the VHF on a fuse/breaker of its own, because you don't want ANYTHING else to be able to trip the breaker and kill your VHF in an emergency. But then, the rest of the electronics are usually fine being lumped on one circuit, which makes it simple to turn them all on/off at once. So, there's nothing "wrong" about the way they've been split up.

mitiempo 01-18-2014 10:55 AM

Re: Engine start shuts off chartplotter
 
Quote:

Originally Posted by hellosailor (Post 1319418)
No need for a starting battery...

Depends. If the current gel batteries are older and have lost capacity over time the problem may persist. If that is true it will only get worse. I would install a starting battery or you may have to call for a tow one day.

Definitely resolve the JB Weld problem and any other iffy connections.

Maine Sail 01-18-2014 11:42 AM

Re: Engine start shuts off chartplotter
 
The problems are / could be:

1- Aged batteries beyond their useful life. No healthy 500+ Ah GEL battery bank should EVER drop electronics even at 50% SOC when starting a 4J Yanmar.. Something is simply wrong...

2- Poor wiring or connections creating undue voltage drop during starting. The best place for an engine negative connection is directly to the mounting bolt for the starter itself.. This helps minimize passing hundreds of amps through paint, dissimilar poor conducting metals and rust.

3- Poor choice of DC loads tie in to the system wiring...

4- Undersized wiring, poorly executed terminations or poorly wired batteries...

Three healthy GEL 8D's should barely dip starting a Yanmar 4J. This is absolute cake walk for them and you should be seeing a bare minimum of 4000 cranking amps at normal cruising temps!!!!

Clean all connections, move the negative to the bolt that holds the starter to the engine (buy a longer bolt if necessary) and let us know how that worked.......

Gladrags1 01-20-2014 06:35 AM

Engine start shuts off chartplotter
 
Thanks everyone for your contributions! I know that I first need to address that ground. Mainsail: thanks for the suggestion about connecting it to the bolt connecting the starter. Access is tight back there but I will see what I can do. I think that may solve my issue and will update the group once done and I've been able to assess the situation.

Steve: I will PM you once I get home from visiting my in-laws. I am interested in seeing your thoughts about this.

Tod


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