Electrical Issue 2007 Mercruiser 4.3 inboard outboard e

Sunpacceo

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I have been troubleshooting a starting issue today on a friends boat. He asked if I would come over and take a look at his Monterey as I would not start. He thought that it might me the solenoid however that had been replaced recently. The boat had been sitting for about 4 months and he found that the key had been left in the on position an the battery was dead.
He had just installed a new battery and It is fully charged. I started the trouble shooting at the kill switch and it appears that is working properly. When I turn the key on the alarm sounds and when you kill the switch the alarm dies. Reset the switch and the alarm again sounds so I determined the switch to be working correctly. I then moved to the starter slave solenoid....this part sounds as though it is engaging properly when you turn the key. You do hear a click inside the unit which I believe implies this part is engaging properly. I'm not sure how else to trouble shoot this part so I moved on to the starter solenoid. Red cable is received a full 12v however, the yellow/red wire is not hot even when the key is turned. I did go ahead a jump the solenoid yellow/red terminal to the RED lead and the engine turned over and even fired so I determined the starter was working right but not sure about the solenoid.

QUESTION:
Is the yellow/red wire suppose to energize the starter solenoid when the key is turned?
How can I test the starter slave?
Anything else I am missing which is not allowing power to get to the starter via a switched lead?

Thank you very much in advance.
 

Pete104

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Re: Electrical Issue 2007 Mercruiser 4.3 inboard outboard e

The solenoid can sound like it works but doesn't. The slave energizes the starter solenoid. Just like when you jumped the heavy red & yellow red @ the starter.
If connections are clean everywhere else, replace the slave solenoid. I prefer OEM with these items, although in a pinch do what ya got to do!
 

Sunpacceo

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Re: Electrical Issue 2007 Mercruiser 4.3 inboard outboard e

Do you know of a way to test the slave solenoid?

solenoid.jpg
 

Pete104

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Re: Electrical Issue 2007 Mercruiser 4.3 inboard outboard e

Take and jump from the yel/red terminal to 12v. You should get battery voltage the heavy yel/red.
 

cdiamond

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Re: Electrical Issue 2007 Mercruiser 4.3 inboard outboard e

the solenoid is a electromagnetic switch
the purpose of a solenoid is to let a low amperage circuit control a high amp circuit

the small post with the yellow/red wire activates the solenoid - hence the click
as stated clicking does not always indicate proper function

to test the solenoid - use a test light or voltmeter
activate the solenoid ( small post yellow/red )

the large posts on top of the solenoid are

red -battery voltage

yellow/red -to the starter solenoid

when activated there should be 12v at the large post yellow/red

it is very common for these solenoids to become intermittent and eventually fail

good luck and safe boating
 

tpenfield

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Re: Electrical Issue 2007 Mercruiser 4.3 inboard outboard e

Yes, everything is pointing to a bad solenoid. Since you jumped the solenoid and the engine cranked you can assume that the starter solenoid is good and the slave is the bum.

FWIW here is a pic of the connections to the starter. The red/yellow (right-most wire) is the activation wire that leads back to the slave.

StarterConnetions.jpg
 

Sunpacceo

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Re: Electrical Issue 2007 Mercruiser 4.3 inboard outboard e

Thank you for your reply. I think that with your answer I only have one last question and the mystery will be solved. Is the red wire on the slave post suppose to be 12 volt? I do not have 12 volt going to the slave. Where does the 12 volts come from? directly off the battery?
Thanks
 

tpenfield

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Re: Electrical Issue 2007 Mercruiser 4.3 inboard outboard e

Yes, the red wire going to the slave should be live with 12v. It comes from the starter terminal, which merely acts as a junction for the battery lead, the red wire and the orange wire (leads to the alternator). The slave then connects the red wire to the yel/red wire upon activation, and activates the starter solenoid.

It is kind of a funny loop that the current takes to activate the starter solenoid. It begins at the starter junction terminal (stud) goes up to the slave solenoid (red wire), then back down to the starter (yel/red wire).

So, if you do not have 12 v on the red wire at the slave, then the red wire may be broken or not connected properly.

Update: I forgot about the circuit breaker . . . the red wire goes there first, and then becomes a red/purple wire from there to the slave solenoid. (maybe check the circuit breaker . . .)
 

Sunpacceo

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Re: Electrical Issue 2007 Mercruiser 4.3 inboard outboard e

Just checked. Red at slave is not 12v. No power here. I know you said it comes off the starter solenoid or does this lead come from somewhere else?
 

ENSIGN

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Re: Electrical Issue 2007 Mercruiser 4.3 inboard outboard e

If you do not have 12v on that red wire,check the circuit breaker next to the slave solinoid.it should be hot on both terminals
 

tpenfield

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Re: Electrical Issue 2007 Mercruiser 4.3 inboard outboard e

Just to be clear Red comes from the main junction at the starter (not the starter solenoid connection, that is the yel/red) It then goes to the circuit breaker and becomes red/purple and on to the slave solenoid.

there are some wiring diagrams posted on various threads here. If you Google (mercruiser 4.3 wiring diagram) you should find them. Also, it will be in the Mercruiser manual for the 4.3, which there are some download site for as well. It is kind of tough to explain, and the pictures in the diagrams will do it so much better.

I think I may have added some confusion in my earlier posts as I forgot about the circuit breaker. . . .
 

Sunpacceo

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Re: Electrical Issue 2007 Mercruiser 4.3 inboard outboard e

Now I am getting somewhere. The circuit breaker is not hot on either side. The reset also appears to be out( I'm not sure if it even pops oust since I've not worked with on my outboard) Power too one of the terminals I would guess should be 12v even if the circuit is tripped I would think.

I guess now I am at no power to the circuit breaker.
 

Fun Times

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Re: Electrical Issue 2007 Mercruiser 4.3 inboard outboard e

Now I am getting somewhere. The circuit breaker is not hot on either side. The reset also appears to be out( I'm not sure if it even pops oust since I've not worked with on my outboard) Power too one of the terminals I would guess should be 12v even if the circuit is tripped I would think.

I guess now I am at no power to the circuit breaker.
Are you getting 12V to the orange wire off the back of the alternator? If not, then there is a pretty good chance the 90 amp fuse hooked to the starter cable stud is bad.

Since you have no power at the circuit breaker hopefully it will be either the 90 amp fuse or a bad connection with the main wire harness running between the boat and the engine.

Mercruiser part number 88-79023A91 FUSE ASSEMBLY, 90 Ampere

Good luck.:)
 

Don S

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Re: Electrical Issue 2007 Mercruiser 4.3 inboard outboard e

Since you have power to the helm and the starter slave solenoid is clicking, then you don't have a bad 90A fuse on the starter, and the circuit breaker is working. If you checked the circuit breaker with a meter and put a test lead on each terminal and got 0 volts, then it's working fine, that is a voltage drop test, not test for voltage. You need to have your black meter test lead on a good ground to test for voltage.
Use the link dubs posted to check your starting system. Here it is again http://forums.iboats.com/showthread.php?t=167035
 
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