Help Electrical problem

[Steve04]

Hello guys, hopefully you can help, launch last week everything went fine, some how, left batteries on for 5 days before returning to boat. Stb batteries were discharged and would not start stb engine. Ran generator to charge batteries, and started both engines. Used the boat over the weekend and charged both batteries using the battery charger for two days while docked. today, check boat and the Stb battery switch in the cabin would not light, but I checked the voltage and it was about 12. Started the engine and in looking at the instruments none of the guages worked and the battery alarm signal was on the stb indicator. and the Central guage indicated no Tech found.
What happened the engines were running, fine, but no guages, I am thinking one of the stb batteries are bad, and will test tomorrow. but I could not find anything in the manuals. I have a 2004 34, with 8.1s Help....

Steve O4

 

[tobnpr]

You say the engines were running fine, but no gauges. Both sets of gauges were not working?
I can't think of anything that would cause that other than a bad ground at the panel. With the engines running, independent of the batteries, you should have plenty of juice at the panel from the alternators (you said the battery showed 12v, so we know it's not shorted). Far more likely that the ground is bad than both ignition circuits supplying power to the gauges going bad at the same time. I'd start by checking voltage at each voltmeter (engines running) with a jumper directly to the battery ground, and continue troubleshooting from there.

 

[Steve04]

dear tobnpr, thank you for your response, I am not an expert in electrical so my first dumb question, would the bad ground cause the light on the stb battery switch not to light, and then cause the gauges not to function? I understand that my gauges are run from the stb batteries, but everything worked on Monday. Could it be a bad battery? other wise everything sounded fine, the genny started and ran, both engines etc... just the stb side gauge showed the alarm signal for batteries. thanks for your input.
Steve

 

[Four Suns]

My "analog" engine gauges will not work if the battery is bad... been there...

Also, if the battery is bad on my genny, it'll shut down and won't run.

 

[tobnpr]

My "analog" engine gauges will not work if the battery is bad... been there...

Also, if the battery is bad on my genny, it'll shut down and won't run.

If the battery's bad, how did the engine get started?

The power that is supplied to the gauges is from the ignition circuit for each engine. Port engine gauges are powered by port engine battery, stbd. from stbd. The ignition circuit becomes hot when you turn the key- that's when the gauges come on.
You say the battery is good enough to start the engine, there's no reason the gauges would not function other than a bad ground or disconnected wire from the ignition circuit that powers the gauges.

I'm not familiar with a "battery switch" that would not light for your particular vessel. If there is something additional wired in between the ignition circuit from the key switch and the gauges, the problem could lie there. Again, I'm basing this guess on the premise that your batteries are good...

 

[In Two Deep]

Did you check the fuses?

 

[Four Suns]

If the battery's bad, how did the engine get started?

I have three methods I use. The first is a pull cord I wrap around the flywheel and start it like a lawnmower. If that doesn't work, I have someone pull the boat real fast to turn the props/shaft and then I pop the clutch and turn the engine. The third method is to hit the "emergency start" switch which connects the port and starboard batteries together to jump them.

My boat doesn't have ignition keys to start the boat but rocker switches (I think all the newer diesels have that). I don't have a clue how these analog gauges work other than they are electric and need a few seconds of juice to spool up before the engine is started and so they are not really "analog". For example, I don't have a cable running down to the transmission that spins for the tach... I do know, however, when the battery is low, the gauges will not spool up and if you hit the emergency button to jump the engine or the battery has all it's remaining juice sucked out by the starter (caused from running the house battery low, battery going bad, etc.) the gauges are put in a state of funk. The check engine light may even come on and stay lit. What I do is let the engine run a few minutes, turn it off, and the restart it to clear the gauges up.

Maybe this is unique to me but I don't believe I have grounding problems or other electrical problems because I ran a battery down.

My assumption has always been that the "analog" gauges use the same sending units as the digital gauges do but put it in an analog format... but I may be wrong on that. The only real analog gauges that I believe are on my boat are the gauges mounted directly on the engines.

 

[Steve04]

Guys, thanks for the input, I purchased two new batteries and will install them tomorrow. if that works great, then I buy two for the port side. My questions, regarding the toggle switch for the engines to energize has a light behind it, and suddenly the light did not work, as well as the voltage meter on the main control panel when the stb switch was energize. but when tested with the toggle switch on the control panel it show 11 volts, or thereabouts. the gauges on the dash on both the port and stb did not work even after the engines were started.
I don't believe its a corrorisn problem the engines are immucuate and spray with anti corrosion spray twice a month. Perhaps a fuse where would I look for the fuses for the gauges?
Thanks for your input and help,
Steve 04

 

[dpvandy01]

Steve,

good luck with the problem. what brand of batteries did you go with?? It is also very helpful to only post your question in one category. Multiple postings of the same question does not get you better results

 

[tobnpr]

Did new batteries solve the problem?