help with battery drain?

[ratking20]

i have a 350 mercruiser 5.7 i/o

fyi ive been doing alot of searching and reading posts to help get a better knowledge of the situation

after getting the boat running and ready to go this year, a few days later it wouldnt start
i have a dual battery setup(blue sea add a battery) one batt dedicated for starting, one for everything else
so the boat wouldnt start. was hearing a single click when starting(which from reading could prob be the slave solenoid)
i remember the boat wouldnt start a week ago with the batt switch set to on( other option is combine)
but when switched to combine it would start(that would tell me the starting battery is dead)
now both seem to be dead. and still getting the single click and nothing else.

so i went out and bought another battery. i disconnected the dual battery setup and have just the new battery. too many wires everywhere with the dual setup and acr. wanted to keep it simple and go from there. but it still wont start. still get a single click.

i disconnected the positive cable off the battery and uses a multimeter from the cable to the battery(when ignition is set off) and it reads 3.6 but i had it in volts.im not sure if that means anything but i will test it again in amps tomorrow. i know finding the problem is going to be a ***** i assume. im not very knowledgeable in electric and/or engines. but im no idiot either. but shouldnt the engine still start????

could the slave solenoid if it was the problem cause the drain? could the drain have caused the slave solenoid to go bad? if it actually is the problem. are the two related?

my first plan is to replace the slave solenoid. i know it could also be the starter solenoid. i did have a new starter put in very recently. so who knows. i also plan on checking and cleaning all the connections. what else can i do to figure this out?

any help would be great...... thanks in advance?

 

[slothman]

Re: help with battery drain?

just curious....do you have any aftermarket stereo equipment ?

 

[ratking20]

Re: help with battery drain?

i do. but hasnt been hooked up yet this year. i have the wires ran but the waterproof faceplate or the radios control box are not yet installed. its hooked up to a bus bar and then to the battery switch so it shouldnt be drawing anything from the batt when switch is off. assuming the switch is working

 

[dingbat]

Re: help with battery drain?

i disconnected the positive cable off the battery and uses a multimeter from the cable to the battery(when ignition is set off) and it reads 3.6 but i had it in volts.im not sure if that means anything but i will test it again in amps tomorrow. i know finding the problem is going to be a ***** i assume. im not very knowledgeable in electric and/or engines. but im no idiot either. but shouldnt the engine still start????

could the slave solenoid if it was the problem cause the drain? could the drain have caused the slave solenoid to go bad? if it actually is the problem. are the two related?

my first plan is to replace the slave solenoid. i know it could also be the starter solenoid. i did have a new starter put in very recently. so who knows. i also plan on checking and cleaning all the connections. what else can i do to figure this out?
any help would be great...... thanks in advance?

Your starter requires at least 12V to operate correctly. The drop to 3.6V tells me that you don't have the necessary current. Either the battery is bad or you have a cable problem. BTW: Don't use your VDM to check amperage on that cable. You'll damage the meter.

Why are you focused on the solenoid? The click you hear is the closing of the relay. That's normal operation. Instead I would focus on the cables, then jump to the starter itself.

Use a pair of jumper cables an go directly to the terminals on the relay. If it starts, you've narrowed the problems to cable/switch problems. If it doesn't start, bypass the solenoid by connecting the jumper cables directly to the starter, If nothing happens, your starter is bad...not uncommon for a boat.

If everything is seems good, remove the cable running to the starter from the battery post and measure the current going to the starter with and without the key on. You should get nothing, or very little if anything. If you get nothing here, you have something wired to the starting battery that is pulling the system down. A hung float switch resulting in a burnt bilge pump are notorious for such problems