No power on yellow-red wire to starter...please identify this Mericruiser part

[RickeyD07]

I own an 06 Azure DB powered by a 2015 I/O 5.7 350 MPI Mericruiser engine..... Recently purchased and I changed out the dash with all new switches and ignition. New blower motor. Went to warm the engine for an oil change, nothing...all accessories work but no power at ignition. I've changed the 90amp fuse at the starter, checked the 50amp on top of the engine, replaced the 20amp running along the bulkhead behind the motor. There is 12.7amps on the red wire to the 90amp starter-fuse and 12.7 on the wires from the 90amp fuse but no power to the smaller yellow-red wire connected to the starter even when key is turned to start. Tracing the yellow-red wire there is an attach point on top of the motor immediately forward the red 50amp reset circuit breaker (please see photo)...I noticed the object has two-terminals: one terminal receives a blue-red (purple) wire that is hot (12.7amps) and the other terminal receives the yellow-red wire which is not hot...even when I turn the ignition to start. This object also receives a black ground wire.

Is the yellow-red wire at this junction supposed to be hot? Could this be the culprit not allowing power to the switch or the starter? Does anyone know what the object is called so I can replace if warranted? Thank you, Rick

 

[Bondo]

Ayuh,...... Welcome Aboard,...... Go back to the keyswitch,......

Do you have 12v power at the red wire on the batt terminal,..??

If so, with the key turned to "Start", there should be 12v power on the red batt wire/ terminal, the purple wire/ terminal(ignition), 'n 12v on the red/ yellow wire/ terminal(starter excite),.....

The red/ yellow start wire goes from there, Through the neutral safety switch in the control, to the big cannon plug on the motor, to the slave solenoid(yer picture I believe), down to the starter's solenoid, at the tiny terminal nearest the motor's block,.....

 

[RickeyD07]

Thank you Bondo...truly appreciate the information. Earlier, I finally located a legible copy of the vessel's wiring and studied it. I took the multimeter and checked, once again, the power to the starter from the battery and from the starter...all good. I then checked the power to the canon plug...power present to the large pin but no power to or from the smaller pin (yellow-red wire). Once again I checked what I've discovered to be the the "starter slave solenoid"...I have power going to the solenoid through the red-blue (purple?) wire but that power is not transferring over to the yellow-red wire and then to the canon plug or the starter. It is an assumption on my part that the starter slave solenoid is bad and requires replacement? Your thoughts? Thanks again Bondo, Rick

 

[Bondo]

What about at the key switch,..??
It excites the slave solenoid,....

Is the control lever in Neutral,..??

 

[RickeyD07]

Control lever is in neutral...tried two ignitions...no response...as I mentioned, the slave solenoid is receiving power from the red-blue wire but it's not transferring that power to the yellow-red wire...there is no voltage to the yellow-red wire at either terminal on the solenoid...for that reason, I'm guessing the solenoid is defective...is that possible?

 

[Lou C]

First test the ignition switch:
B terminal (Battery, red wire) has batt volts whenever bat switch is on
I terminal (ignition, purple wire) has bat voltage when you turn ignition on
S terminal (start, yellow/red wire) has bat volts when you turn key to start

If you don’t have your switch working this way check the ignition fuse in the fuse box. Do the gauges power up when you turn the ignition on?

 

[RickeyD07]

Thank you Lou...when I turn the key to ignition...nothing powers-up but I do have power to my blower motor, lights, bilge pumps. I traced power from the battery to the starter (large red battery wire) - 12.7 at the 90amp fuse. From the fuse, 12.3-12.7 but the smaller yellow-red wire attached to the starter is not powered...nothing.

Moving up the engine and wiring harness, I checked the starter slave solenoid...the blue-red wire to one of the terminals is hot but the yellow-red wire attached to an adjacent terminal is absent power on the major terminal and the secondary terminal on the side of the solenoid as well.

The 50amp red-button breaker next to the solenoid was never activated...remains set and powered.

When I checked the canon plug...there is power to the large pin (red wire?) on both the pin and the receptacle side but there is no power to the smaller pin or receptacle which I believe is the yellow-red wire; therefore, I'm guessing that the starter slave solenoid is the culprit as it's not transferring the power received from the blue-red wire over to the yellow-red wire to complete the start sequence?

This is just an uneducated "guess" on my part seeing that the initial power is generated from the battery and the initial power sequence is isolated from the ignition-in the dash until a circuit is completed involving the blue-red wire (power) feeding the yellow-red wire at the slave solenoid?

Until the yellow-red wire receives power at the solenoid, the switch cannot complete the circuit? Does this make sense? I'm currently seeking to replace the starter slave solenoid...will locate the correct part number for my engine and purchase online or at a local dealer...if that does not work...I'll keep searching. Any advise? Thank you for your help, Rick

 

[Lou C]

The slave solenoid is always “hot” but the only way that yellow/red wire gets powered is from the ignition switch. The power travels from the ignition switch to the solenoid (really a starter relay). So you need to check what’s coming off your ignition switch. Then go from there.
PS I had the same exact problem on my old Four Winns about 10 years ago. No crank, no gauges; tilt &trim & blower worked. Checked ignition fuse and no current flowing across it ……all it was: oxidation on the old style glass fuses.
I just replaced all the old fuses and it’s been fine ever since….

 

[RickeyD07]

The slave solenoid is always “hot” but the only way that yellow/red wire gets powered is from the ignition switch. The power travels from the ignition switch to the solenoid (really a starter relay). So you need to check what’s coming off your ignition switch. Then go from there.
PS I had the same exact problem on my old Four Winns about 10 years ago. No crank, no gauges; tilt &trim & blower worked. Checked ignition fuse and no current flowing across it all it was: oxidation on the old style glass fuses.

Thank you...I replaced the glass fuse and the housing as the old fuse, though "good" as the filament was intact, the old fuse cap has separated from the glass housing and was stuck in the fuse housing. This is the inline 20amp fuse (red wire) running along the bulkhead of the transom wall behind the motor. Is there another fuse from the starter that I don't know about? I bypassed the safety switch at the throttle controller to make sure the old switch was not malfunctioning. I see no other fuses along the wires from the starter running through the bulkhead back to the motor but a good portion of the wires are not visible as they're concealed in the wall housing. I did detach the ignition wires from the harness and checked the harness...only received about 7amps on the red-wire...all other connectors were dead.

 

[Lou C]

In the boat fuse box under the dash there will be a 10 amp fuse for the ignition circuit…

 

[Bondo]

Until the yellow-red wire receives power at the solenoid, the switch cannot complete the circuit? Does this make sense?

No,...... The power for the red/ yellow wires, COMES FROM THE KEY SWITCH,........

 

[Lou C]

What I said lol that oxidized fuse really had me scratching my head. Multimeter check showed continuity thru fuse…BUT due oxidation in the fuse box itself there wasn’t continuity from the tabs holding the fuse TO the fuse! Probably should have installed a whole new fuse box!

 

[Lou C]

PS
that solenoid is used to prevent voltage drop due to the long wiring run.

 

[RickeyD07]

God Bless you Bondo and Lou...you guys got me to thinking and two-things were preventing my boat from starting. First, I went the extra mile to renovate the older boat with a new dash and new ignition....nice...all the switches worked but the ignition...it was four prong and my wiring harness was set-up for a three-prong...the new starter harness did not make contact with the needed attach points...this was made obvious when you two insisted that I focus on the ignition. I initially did not suspect the ignition because I tried the old ignition when the new one did not work...the old one did not work either. Finally, I located an inline 20amp fuse on the bulkhead...when I pulled the housing apart for inspection, the metal cap separated and stuck in the housing...so I replaced it with another fuse housing and fresh fuse. Today, I continued tracing power back to the ignition and noted the yellow-red wire was dead when the key was turned...so I hooked-up the old ignition and yes...the old girl started up. Thank you both very much for your time and patience...now...another fire to put out....my up-trim is not functioning at the throttle...but again, thank you both very much.

No,...... The power for the red/ yellow wires, COMES FROM THE KEY SWITCH,........

 

[RickeyD07]

PS
that solenoid is used to prevent voltage drop due to the long wiring run.

God Bless you Bondo and Lou...you guys got me to thinking and two-things were preventing my boat from starting. First, I went the extra mile to renovate the older boat with a new dash and new ignition....nice...all the switches worked but the ignition...it was four prong and my wiring harness was set-up for a three-prong...the new starter harness did not make contact with the needed attach points...this was made obvious when you two insisted that I focus on the ignition. I initially did not suspect the ignition because I tried the old ignition when the new one did not work...the old one did not work either. Finally, I located an inline 20amp fuse on the bulkhead...when I pulled the housing apart for inspection, the metal cap separated and stuck in the housing...so I replaced it with another fuse housing and fresh fuse. Today, I continued tracing power back to the ignition and noted the yellow-red wire was dead when the key was turned...so I hooked-up the old ignition and yes...the old girl started up. Thank you both very much for your time and patience...now...another fire to put out....my up-trim is not functioning at the throttle...but again, thank you both very much.

 

[Lou C]

The only difference between a 3 position and 4 position ignition switch is that the 4 has an additional accessory position that allows you to run accessories without turning the ignition on, just like in a car.
The trim system has a blue wire for up and a green for down, check to see if you have a bad trim switch or broken wire inside the remote control....

 

[RickeyD07]

Thanks Lou...the attach point for the wiring harness on the "new" console, the prongs that insert into the original wiring, don't match exactly...I tried to swap the yellow-red/red-blue wires around the four prongs with no results...but the old ignition fired up with the new 20amp fuse.

Concerning the trim...the trailer remote location aft works good (up and down) and the "down" trim on the throttle is operating. The up trim on the throttle has no response. The limiter on the stern looks new...I removed the plastic cap and found it spotless with a little waterproof grease to seal it...but the trim solenoids in the engine housing are old...the nuts-bolts corroded; obviously, there is direct power to the trim motor-pump as it remains hot without the battery switch activated so taking the battery off-line is probably advised to begin a search for the problem?

I'm guessing I should replace both solenoids while I'm struggling to reach the remote area up next to the bulkhead behind the motor...maybe replace the bolts and nuts as well...clean the corrosion and see if that makes a difference? I'm reluctant to start dismantling the throttle internals as I have no clue what to expect there.

Any other suggestions? Have you repaired the remote trim switch in the throttle; if so, how labor intensive was it? Thanks.

 

[Lou C]

If your tilt n trim works up & down from the trailer remote switch but not from the remote control shifter the solenoids are working as they should but the “up” solenoid is not getting the signal from the “up” wire (blue) on the remote control shifter. Could be the trim switch in the remote control shifter or a broken wire inside the control, I fixed mine a couple times what happened is the insulation rubbed through and I was getting a shock if I trimmed while touching the metal helm wheel. Liquid electrical tape makes it easy. Not a hard repair. I have a new remote control I am going to install this season to finally replace the 34 year old OMC control.
You can clean the terminals on the relays as preventative maintenance. I had to do that once as well. Mine has the huge relays that are like an old Ford starter relay that never go bad. The trim relays always are hot, the blue or green wires trigger the relays…
With the ignition switch it must have been hooked up wrong….glad you fixed it…
B= battery red wire
I= ignition purple wire
S= start yellow/red wire
The B,I,S are all marked on the switch….

 

[RickeyD07]

Thanks again, Lou...I won't mess with the solenoids if they both play a role in the proper function of the trailer switch as I'm able to move the prop up and down at that point...I'll focus on the throttle's trim button and see if a wire has been compromised relevant to the "up" trim...though I'm a little concerned about opening up that can of worms. Thank you for labeling the attach points on the switch and clarifying what those letters represent...much appreciated. I'm going to try and integrate the new dash once again but use the old wiring harness to the ignition side that properly fits the connection in the helm... Thanks for all your help...

 

[Lou C]

Glad to be of help. "Electrickery" is a mystery for most of us, it takes time and study to really understand it!
One lucky thing older boats have very simple DC wiring, one thing I would NOT want is a modern boat with CANBUS and multiple ECMs, what a nightmare that will be when those boats get older. Keep the old simple stuff going.