Logo
FULL SITE MENU

4.3 MPI Not Starting - Starter solenoid click

O

okubricko

New member
Hey there, this is my first post on this forum so thanks in advance for the help.

I have a 2016 SeaRay with a Mercruiser 4.3 MPI engine. Yesterday I tried to start it and I am getting a single click on the starter solenoid when I turn the key. The battery(s) is good (I've tried two different batteries 1st is a 1 year old battery with 12.54v and the other is a brand new battery 12.72v). When I try to start the boat I get a single click from the starter solenoid but the boat doesn't turn over. Blower and bilge pumps work. The radio isn't turning on.

I have Vessel View hooked up and am getting the error "4602-23 Fault Blocker System Voltage"

There is one other thread that I've found in all my internet searching with that error which is here >> https://www.bbcboards.net/showthread.php?t=1104712

>>FAULT BLOCKER: SYSTEM VOLTAGE

You need to turn your battery switch on. The PCM can wake because CLEAN POWER is provided (as required) via direct connection to the battery. However, MPR voltage is not present because you have the battery switch "off".

In this case, almost certainly caused by a "user error". Turn key off, properly supply battery connection (via switch) and he fault should no longer be actively displayed.
That seemed as simple as the owner not turning on the battery switch. <<

That's not my case, I have the switch on the throttle set to Run. Its working because if its off the boat doesn't beep when I turn the ignition on,

I've checked all the fuses I can find. The 50 AMP breaker, all the fuses on the engine block, fuses at the helm, 90AMP on the starter and all look good. It seems like there is something I am missing and something isn't getting power.

One other item, and this is probably a big one. I just installed Vessel View this spring, when I installed it I brought the battery off the trickle charger and hooked it up backwards. It was like that for 2-3 minutes, nothing popped or smoked that I saw or smelled. Could there be something that I fried? I would hope there would be protection built in, fuse or breaker, but I haven't found anything like that fried. Also, Vessel View connects, gauges work, so it seems like the computer isn't fried.

Any and all help would be appreciated.
 
The slave activates the starter`s solenoid if the click is the slave jump the Red/purple and Yellow/red terminals. motor should spin. If Yes, replace the slave
 
find the starter...then the Yellow/Red wire on the starter...follow that wire back up to the slave solenoid.

Probably be a really good idea to make sure your ground cable(s) is clean and tight - on both ends.
 
makomark said:
find the starter...then the Yellow/Red wire on the starter...follow that wire back up to the slave solenoid.

Probably be a really good idea to make sure your ground cable(s) is clean and tight - on both ends.
Click to expand...
Thanks for the info, I’ll have to check it out after dinner.
 
Here’s what I found. On my engine I don’t have a slave solenoid, but relays for the main power, fuel pump and starter.
7B70DDFB-B2FE-40B4-A813-A488F75798EA.jpeg

The starter relay was clicking when I turned the key. I swapped it with both the fuel pump and main power relay and all three clicked. I plugged the main power in as well as the starter and it still didn’t crank.

I keep going back to the Fault Blocker System Voltage error being the issue. As in the post I noted the PCM has power but the MPR doesn’t have voltage.

Here are what the relays look like
CC122679-22F9-4852-9B43-8A6F3E859E81.jpeg
B165AB36-A548-47DD-A26A-86A76959C555.jpeg
 
I am NO expert with EFI systems but this is what I found (see image).
It points to LOW Voltage. Could be weak connection at battery or ground.
I would Load test battery or if you have a spare, swap it out with a fully charged battery and retry.


4602-23.JPG
 
kghost, thanks for the info, battery was at 12.74v. I'll check it again and see and put it on the charger. Where did you pull that information from?
 
Also, Battery voltage does not mean the battery is good. You could have a weak ground to block and still see 12.74 volts

A proper load test is needed to see if the battery output drops under load.

100 amp load test for about 20-30 seconds should be enough.
 
kghost said:
Also, Battery voltage does not mean the battery is good. You could have a weak ground to block and still see 12.74 volts

A proper load test is needed to see if the battery output drops under load.

100 amp load test for about 20-30 seconds should be enough.
Click to expand...
I'll check my grounds as well. I haven't done that yet.
 
did you check Voltage at the starter relay? You swapped relays and no change but the battery voltage at relay is unknown.
 
The grounds are solid as far as I can tell. Tight and no corrosion. I assumed that since the relay was clicking that it was getting the required 12v to close the contacts.
 
okubricko said:
The grounds are solid as far as I can tell. Tight and no corrosion. I assumed that since the relay was clicking that it was getting the required 12v to close the contacts.
Click to expand...
A lack of 12 volts could be the reason.

The scematic is on the relay..
Do you understand how to read it?
 
Connection 85 & 86 are the key swith.
That energizes the relay coil.
I believe 30 is the batttery voltage and goes to 87 in the "off" or normally open state (no output). .

When the relay coil is energized the contact moves and transfers 12 volts to 87a which should be the large yellow with red stripe wire which goes the the starters solenoid.
 
kghost said:
A lack of 12 volts could be the reason.

The scematic is on the relay..
Do you understand how to read it?
Click to expand...
I’ll check to see if the relay is getting 12v. I was assuming it’s getting it because the contacts are closing and the relay clicks when I turn the key, but I’ll verify
 
The starter relay has 12v across 85&86 when I turn the key.

I would think that the main power relay and the fuel pump relay would also have power but I’m not seeing any.
 
Thats correct, but that only engergizes the relay coil.
Line 30 is the battery 12 volts that gets switched to 86a to starter solenoid but is not and the clicking is telling you that..
So where ever 30 comes from (what wire or power source inside module relay is attached to) does not seem to have the 12 volts...if that makes sense.

You are missing voltage somewhere.
You may try unplugging connectors and plugging them back in and check for changes after each to see if one ia the cause.

I dont have schematics for your system.
Not much else I can offer.
 
After some more research and checking with a Mercruiser certified mechanic on another board it turns out that the 90 Amp fuse was blown. I had looked at some pictures online and thought they failed catastrophically, but they don't look any different physically when their blown.

For future reference, if you hook up the battery backwards and reverse the polarity, replace the 90 Amp fuse, it you have all the correct sized sockets it should take about 20 minutes.

Thanks for all the help anyone who replied to the thread!
 
okubricko said:
The grounds are solid as far as I can tell. Tight and no corrosion. I assumed that since the relay was clicking that it was getting the required 12v to close the contacts.
Click to expand...
The most common failure mode for starter relays/solenoids is to actuate ( click) but have contacts that are in poor shape and do not conduct enough current to actuate the starter.
 
Ches4603 said:
Mines just not clicking or anything. Power to everything else. Changed starter, new batteries, 90 and 110 and still nothing.
Click to expand...
might be better to start your own thread and tell us what you are working on. Did you check both positive and negative battery connections and connection at cannon plug from helm harness to engine harness ?
 
Back
Top