Merc 3.0 No power to dash...no 90 amp fuse.

L

LakeMeader

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Went to start up for the new season and I have power to the trim but nothing to the dash. Been reading a lot about the 90 amp fuse on the solenoid but there is none.

Both sides of solenoid are hot as well as the 50 amp circuit breaker. Fuses under the dash are all good but no power. Battery is new and like I said trim works fine. Is there a reason mine doesn't have the 90 amp fuse that everyone talks about or maybe my model has another located somewhere else?

Thanks for the help!

LakeMeader
 
achris

achris

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Re: Merc 3.0 No power to dash...no 90 amp fuse.

LakeMeader, Merc have been using the 3.0 litre engine since 1968, so we need a little more information to track down the right wiring diagram. Can we start with an engine serial number please.

Chris.....
 
Fun Times

Fun Times

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Re: Merc 3.0 No power to dash...no 90 amp fuse.

Also you may have a safety lanyard ignition kill switch that is bad or in the off position. If your boat has one, have you tried toggling the switch on and off a few times to ensure it's in the on position?
 
Bt Doctur

Bt Doctur

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Re: Merc 3.0 No power to dash...no 90 amp fuse.

"Both sides of solenoid are hot as well as the 50 amp circuit breaker"
Then your testing it wrong. If the solenoid was powered on both sides the starter would be active and spinning the motor. Having 12v at the CB is correct.
From there it goes thru the main engine plug and up to the dash. Is there power on the large red wire or the red wire on the ign switch.
 
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LakeMeader

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Re: Merc 3.0 No power to dash...no 90 amp fuse.

Yeah Chris, serial # OK037032


No nothing on the red wire to ignition switch and toggled kill switch several time.
 
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L

LakeMeader

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Re: Merc 3.0 No power to dash...no 90 amp fuse.

View attachment 226658


Ok time to confess....amateur here in electrical things but when I said that both sides of solenoid were hot what I found was while black prod connected to battery ground the meter registered 0 on the top scale when I touched it to the battery side of solenoid and then dropped to about 2.5 when I touched the other side of solenoid.
 
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achris

achris

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Re: Merc 3.0 No power to dash...no 90 amp fuse.

LakeMeader said:
View attachment 226658


Ok time to confess....amateur here in electrical things but when I said that both sides of solenoid were hot what I found was while black prod connected to battery ground the meter registered 0 on the top scale when I touched it to the battery side of solenoid and then dropped to about 2.5 when I touched the other side of solenoid.
Click to expand...

You sure you have the meter on the right scale? You should have it on 'Volts', not 'Ohms'...
 
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LakeMeader

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Re: Merc 3.0 No power to dash...no 90 amp fuse.

I had it on the setting you see in the picture. If you can't see the picture it says 9v BAT Oh and btw Chris I was reading your first reply and I kid you not "Men at Work" came on the radio at just that moment.:laugh:
 
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achris

achris

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Re: Merc 3.0 No power to dash...no 90 amp fuse.

LakeMeader said:
I had it on the setting you see in the picture. If you can't see the picture it says 9v BAT Oh and btw Chris I was reading your first reply and I kid you not "Men at Work" came on the radio at just that moment.:laugh:
Click to expand...

No, the attachment doesn't work. Can you load the picture to a photo site (like Photobucket) and post the link.

You're one of few who got the connection. ;)

Chris..
 
achris

achris

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Re: Merc 3.0 No power to dash...no 90 amp fuse.

LakeMeader said:
Voltmeter_zpsded5f640.jpg Photo by global3guy | Photobucket
Click to expand...

Nope, that's for checking 9V batteries... You need to be set on the 50VDC scale...

attachment.php
 

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achris

achris

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Re: Merc 3.0 No power to dash...no 90 amp fuse.

Bondo said:
Ayuh,.... Click it 'round to 50v, on the left, the yellow numbers on the left of yer picture,...

That's 50v DC, 'n will show 12v,...
Click to expand...

Nope again... The yellow numbers on the left are for AC volts, not DC. DC is on the right, and white numbers.
 
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Bondo

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Re: Merc 3.0 No power to dash...no 90 amp fuse.

achris said:
Nope again... The yellow numbers on the left are for AC volts, not DC. DC is on the right, and white numbers.
Click to expand...

My Bad,... Fixed it,... Shoulda looked closer,...
 
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LakeMeader

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Re: Merc 3.0 No power to dash...no 90 amp fuse.

Ok guys will check in the morning as I'm heading to work right now. Did the wiring diagram show any other possible fuses I might check since mine doesn't have the white 90 amp fuse on the solenoid?

Thanks very much!
 
achris

achris

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Re: Merc 3.0 No power to dash...no 90 amp fuse.

LakeMeader said:
Ok guys will check in the morning as I'm heading to work right now. Did the wiring diagram show any other possible fuses I might check since mine doesn't have the white 90 amp fuse on the solenoid?

Thanks very much!
Click to expand...

No. If you have 12v on both sides of the circuit breaker, and nothing on the red/purple on the back of the key-switch, you have a problem in the harness, probably the main plug. BTW, for testing in these conditions, you've better off with a test light than a meter.

I've had another look at the circuits, and on every engine I've worked on, there is a 20A fuse behind the dash, in the red/purple wire that goes to the key-switch. For some reason, the diagram for your engine is not showing one. Just check and see if you have one there... And check the fuse and the condition of the contacts. I've seen a few engines shutdown by corroded fuse contacts. I always replace the standard glass fuse (it's known as a '3AG' fuse) with a water resistant automotive blade fuse holder and fuse.

3AG fuse

images


Water-proof 'blade fuse' and holder

fuse_holder.jpg


Chris..
 
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Bt Doctur

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Re: Merc 3.0 No power to dash...no 90 amp fuse.

reminds me of a boat i rewired once. customer basically ordered me to go to the boat to find what i did wrong.Had no power to dash, but motor cranked jumping the solenoid. He kept blaming me untill i pointed out the new side lights that he just installed with 3 of his friends on the boat.
A beautiful install but he forgot to check under the gunnels when he bored the 2 inch holes . went right thru the main harness.
So, unless you had done some wiring work proceeed as follows.
check to see if the battery cables are attached and tight. Its not uncommon to have the trim power come off the solenoid + side and the - trim cable go to the battery neg. "Trim works but nothing else works"
jumper the slave solenoids large lugs. motor should spin, if not check battery cable connections especially the neg engine block side.
Report back with results
 
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