Mercruiser electrical problem, no ignition

[Hcliffe]

I have a 1980 Mercruiser I/O engine, 4 cylinder. The transom developed a leak overnight and a lot of water got in the engine compartment. Now when I try to start it, I just hear a single click sound. No starter grinding etc. the dashboard accessories work okay, but the battery indicator shows only 10 volts, and I know the battery is good. Any ideas on where to troubleshoot this electrical problem?

 

[Don S]

Re: Mercruiser electrical problem, no ignition

With only 10 volts, it won't do anything more than click.<br />Get a voltmeter and check the battery, don't just assume the battery is fully charged.<br />Maybe something was left on, or the auto bilge pump ran the battery down. Who know, but untill you get it started, you can't check the alternator or anything.

 

[Hcliffe]

Re: Mercruiser electrical problem, no ignition

Thanks for the reply Don. I had tried 2 different batteries, same thing. I just checked the one battery with a meter, and it reads 12 volts. Could something (bad connection etc.) be pulling down the battery? Can I check how many volts I am getting at the starter/solenoid?

 

[Don S]

Re: Mercruiser electrical problem, no ignition

Could something (bad connection etc.) be pulling down the battery?

Yes, but it's not so much that it's pulling down the battery, the battery may still have 12 Volts, it just can't get to the engine. It could be corroded, loose connections or a bad cable.<br />The cables all have to be TIGHT and CLEAN. Both positive and negative cables. Wingnuts should be throwed away and regular nuts used so a wrench is needed to tighten the cable.<br />I've also seen boats with the terminal on the battery cable loose and dangling by only a few strands.

 

[fishnfiend]

Re: Mercruiser electrical problem, no ignition

Connections to the terminals, connections of the cable ends to the wires, internal contacts in the slave and starter solenoids - lots of possibilities for voltage loss. Don's troubleshooting guide will help you find the problem. If I were you, I would make sure battery is fully charged and capable of taking a load, and shine up ALL battery cable ends and terminals on the starter and slave solenoid (below breaker reset button - above starter) before even beginning to hunt down the resistance. After getting wet, prolly needs it anyway. Have fun.<br /><br /> http://forums.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=012808

 

[Hcliffe]

Re: Mercruiser electrical problem, no ignition

Good info, thanks. Last night I did loosen all the connections on the slave solenoid, starter, and a few others, cleaned them off and reconnected them. If internal slave solenoid connections are a possibility then that could be the problem. I have Don's troubleshooting page printed off and will troubleshoot tonight. Thanks for the help.

 

[Hcliffe]

Re: Mercruiser electrical problem, no ignition

Any chance it is the 50a circuit breaker that I read about on a few posts here, or would I not get the click if that was tripped?

 

[NorthOfDallas]

Re: Mercruiser electrical problem, no ignition

I ended up having a bad cell in my battery. When I jumped it, didnt help, when I charged, didnt help. All the while, I was showing 12v. <br /><br />I suspected this, so I used jumper cables right to the unhooked battery cable's end and it ran flawlessly going straight to my car battery.<br /><br />New battery and all was well

 

[Hcliffe]

Re: Mercruiser electrical problem, no ignition

I tried my boat battery, the battery from my van (which is about 4 months old), and jumping straight from another car. All with the same results. 10Volts and a click.

 

[fishnfiend]

Re: Mercruiser electrical problem, no ignition

Here's Merc's tech bulletin for evaluating starters prior to warranty returns. Similar info to Don's, but sometimes presented a different way makes a difference too.<br /><br />Don't forget about the ground connections also - they're just as critical. Mine near the exhaust riser was all rusted and crusted. I gained almost 2 volts at the starter after replacing the cables.<br /><br />Auto parts stores have two guage battery cables fairly cheap. If you have any doubt about rusted terminals, it's cheap insurance just to go ahead and replace them. You need a 2' for the ground and a 54" for the positive starter cable.<br /><br /> http://www.boatfix.com/merc/Bullet/01/01_11.pdf

 

[JLowe59]

Re: Mercruiser electrical problem, no ignition

If your meter showed 10 volts for your battery from your van and it starts with no problem I would suggest you check the meter.<br /><br />12.6 fully charged<br />12.45 75%<br />12.3 50%<br />12.15 25%<br /><br />Dont waste your time until the reading from the battery terminals are checked.<br />Once you are certain you have a fully charged battery you can then start your troubleshooting.<br /><br />Good luck<br />Jim

 

[Hcliffe]

Re: Mercruiser electrical problem, no ignition

I've confused you guys. I used a volt meter on the battery, it shows 12 volts. But the boat guage shows 10 volts.

 

[Hcliffe]

Re: Mercruiser electrical problem, no ignition

I'm not sure which is the slave solenoid vs. starter solenoid... I took some digital pictures, is there a way for me to attach them to this thread? I don't see an option for that.

 

[Don S]

Re: Mercruiser electrical problem, no ignition

Try this test with your volt meter.<br />Attach the ground of your meter to a good clean surface on the engine.<br />Now, check the following with the red lead of your meter and report all the readings.<br />1. The positive post on the battery. Not the battery cable ends or the nut. The end of the post itself.<br />Volts =________<br />2. Now check the pos cable end that attaches to the battery.<br />Volts =________<br />3. Now check the cable end where the positive cable attaches to the starter.<br />Volts =________<br />4. Now ceck the solenoid terminal where the battery cable attaches to the starter.<br />Volts =________

 

[Hcliffe]

Re: Mercruiser electrical problem, no ignition

See if this link to the pictures works.<br /> http://pg.photos.yahoo.com/ph/hcliffe/album?.dir=/d59cscd&.src=ph&.tok=phveWCFBjTlFfpJ6

 

[Hcliffe]

Re: Mercruiser electrical problem, no ignition

I did most of those tests and received 12 volts. My red cable from the battery does not go directly to the starter, it goes to a solenoid. I get 12 volts there. See the pictures on the link I attached.

 

[pilotkeith2000]

Re: Mercruiser electrical problem, no ignition

First, you can not test a battery with a volt meter! a battery can have a full surface charge and show 12.5 volts and still be bad! you need to test with a cabon pile load tester.And you need to do a voltage drop test. Use a DVOM and test from the neg side of battery with neg cable disconected. place the dvom between the neg side of the terminal on the battery and the negitive cable and read the voltage. if any voltage reads you have a voltage drop in the wiring at some place. Also do this on the positive side (ie) resistance in the wiring. Also test the voltage from the back side of the starter solinoid. disconnect the lead to the starter and test the voltage with a dvom at the post that leads to the starter with it engaged. dvom from starter solinoid to ground. this will check for voltage loss across the contact pionts in the starter soliniod. if less than battery voltage solinoid is bad.It appears All power feeds to gauges are on the power side of solinoid but dont let this fool you. It may be on the ground side of things. Do the voltage drop test. Best info I can give without a wiring diagram

 

[pilotkeith2000]

Re: Mercruiser electrical problem, no ignition

also do the drop test with cables conneted. test voltage from neg side of battery to good clean ground on engine. any voltage showing ? Same with positive side. <br /><br />My bad

 

[Don S]

Re: Mercruiser electrical problem, no ignition

I did most of those tests and received 12 volts.

I need the answer to ALL the questions, not just some of them.<br />I was thinking you had a 3.0L Chevy engine, by your pictures you have a 470 style Mercruiser engine. Not a big deal, but at least now we know what EXACTLY you have and how it is wired.<br />To the tests I mentioned earlier and where I say starter, insert the word Solenoid.

 

[Hcliffe]

Re: Mercruiser electrical problem, no ignition

Don, performed all 4 tests above and received 12 volts reading. <br /><br />So for a 370 engine, is there no slave solenoid, just the one solenoid that I show in the pictures, and there is no solenoid directly attached to the starter? Also, what is the item on the far left in the picture with all the wires, is that a water pump?<br /><br />Could the water in my boat have shorted out the starter and/or the solenoid?