Mercury 90 h.p 4 stroke starting problem

You know the drill..

Moderators: Redneck_Randy, badmoonrising, lakerunner

norske5
Posts: 9
Joined: Fri Oct 15, 2010 8:27 pm

Mercury 90 h.p 4 stroke starting problem

#1 Post by norske5 » Fri Oct 15, 2010 8:56 pm

I have had a starting problem with my 90HP Mercury 4-stroke too... here are the facts:
1. About 120 hrs on the motor (2005) - 40 of them since Sept 1
2. Stopped the motor to watch the sunset and take photos, engine would not startup afterwards. No sound, no nothing
3. Nav lights worked fine - but I think were quite dim
4. Connected a batter charger while everything was connected. After appearing to charge for a brief time, used the remote trim up (on the Quicksilver console) and it operated briefly then quit.
5. Removed battery and put a charger on it overnight - didn't seem to be taking a charge (although now when I think about it it may've been charged - never tested it w/ a voltmeter
5. Replace the battery and no go. This time, not even the nav lights (and things that are normally on in the OFF position weren't there)
6. Inspected under the console - found a black wire with some melted insulation and bare spots... it's one of the wires coming from the ignition harness.
7. Ordered and installed replacement harness - and connected it across the deck of the boat (just to confirm that was it)
8. Still no go. Can't even use the cowl or remote trim up/down - as if there's no +12V power.
9. Fuses (all that I've found, anyway) - check fine. Several withing the starboard side's electrical panel - and one on the +12V connection at the battery. (there are two other connections in parallel - black wires with no apparent fusing).

I've got all of the test gear I think I need (test light, voltmeter, ohm meter)... and am reasonably confident in reading a wiring diagram. It's tough sometimes though to make sure I've found the right part on the motor.

Finally found a Mercury manual on-line,so that's been great help.

Q: Are there any hidden fuses or something that may be bad and I can't see?
Q: Suggested next steps?
Q: Are the relays (starter and 2 trims) what I see right below the series of fuses at the top of the electrical panel?

Thanks in advance.

---------------------
Norske5
2005 Crest 22-ft w/ 90HP Mercury 4-stroke
Decatur IL


User avatar

badmoonrising
Site Admin
Posts: 10066
Joined: Fri Mar 30, 2007 7:04 pm
Location: Chesapeake City, Maryland

Re: Mercury 90 h.p 4 stroke starting problem

#2 Post by badmoonrising » Sat Oct 16, 2010 5:37 am

I split this post ... :rofl

No hijacking :rofl

Ed, Cheryl, Ethan and Aspen.
2013 Sun Tracker Party Barge 22 w/90 HP Mercury, "Hellrhighwater 2"
2014 E-350 Extended XLT.
Chesapeake City ,MD


Ray Jr.
Posts: 687
Joined: Sun Jul 19, 2009 2:54 pm
Location: Warren NH

Re: Mercury 90 h.p 4 stroke starting problem

#3 Post by Ray Jr. » Sat Oct 16, 2010 5:47 am

Did you check the fuses on the motor? There are small fuse blocks under the motor cowl on the starbord side of the motor. I had a similar problem on my 90 this summer after I was messsing around under the console and grounded out a wire by accident and it was a fuse on the motor.

Freedom Lovin' gun crazy Redneck
2010 Premier Sunsation LTD 225 PTX
2010 150 HP Mercury Optimax
got rid of POS 2010 Yacht club dual axle triple log trailer
now have a 2012 Shoreland'r dual axle triple log trailer, MUCH NICER


norske5
Posts: 9
Joined: Fri Oct 15, 2010 8:27 pm

Re: Mercury 90 h.p 4 stroke starting problem

#4 Post by norske5 » Sat Oct 16, 2010 5:57 am

Yes and they all checked OK.

I think there were about 5 of them - some 20a and some 30a. Several of the sets were paired - I'm pretty sure one in each such pair was a spare, though. (checked ALL of them)

Thanks for the tip. Wish that's what it was...

---------------------
Norske5
2005 Crest 22-ft w/ 90HP Mercury 4-stroke
Decatur IL


Ray Jr.
Posts: 687
Joined: Sun Jul 19, 2009 2:54 pm
Location: Warren NH

Re: Mercury 90 h.p 4 stroke starting problem

#5 Post by Ray Jr. » Sat Oct 16, 2010 6:11 am

Their are at least 2 fuse blocks on the motor, and the one that was blown on mine was a 15 amp in the upper block.

Freedom Lovin' gun crazy Redneck
2010 Premier Sunsation LTD 225 PTX
2010 150 HP Mercury Optimax
got rid of POS 2010 Yacht club dual axle triple log trailer
now have a 2012 Shoreland'r dual axle triple log trailer, MUCH NICER


User avatar

Ghost Rider
Posts: 186
Joined: Fri Oct 16, 2009 10:51 am

Re: Mercury 90 h.p 4 stroke starting problem

#6 Post by Ghost Rider » Sat Oct 16, 2010 6:39 am

Check your ground. Follow the cable from the Battery back. It sounds as though you are over thinking this one.

Ghost Rider
1976 20 Foot Flote Bote
40 HP Mercury 4 Stroke
Home : Channahon Illinois
Boating on Cory Lake in MI


norske5
Posts: 9
Joined: Fri Oct 15, 2010 8:27 pm

Re: Mercury 90 h.p 4 stroke starting problem

#7 Post by norske5 » Sat Oct 16, 2010 6:50 am

Ghost Rider - I did check for continuity between the battery ground terminal and the terminal below the starter - and it was fine.

I'll recheck just for certainty, though.

I'll report back later today/tonight about my findings.

Thanks.

---------------------
Norske5
2005 Crest 22-ft w/ 90HP Mercury 4-stroke
Decatur IL


norske5
Posts: 9
Joined: Fri Oct 15, 2010 8:27 pm

Re: Mercury 90 h.p 4 stroke starting problem

#8 Post by norske5 » Sat Oct 16, 2010 6:18 pm

Ghost Rider was right - I maybe over-complicated this one. I now think that I haven't been putting the cable to the battery to the proper terminals.

Before I go and ruin something - any comments from the experts here on my analysis?

Thanks in advance.

markup starboard side motot IMG_2043.jpg
markup starboard side motot IMG_2043.jpg (345.61 KiB) Viewed 4645 times
mark up 640 x 480 engine wiring - colored diagram.jpg
mark up 640 x 480 engine wiring - colored diagram.jpg (186.41 KiB) Viewed 4646 times
markup battery leads IMG_2053.jpg
markup battery leads IMG_2053.jpg (355.67 KiB) Viewed 4637 times

---------------------
Norske5
2005 Crest 22-ft w/ 90HP Mercury 4-stroke
Decatur IL


User avatar

BassFrequency
Posts: 706
Joined: Tue Feb 16, 2010 3:09 pm
Location: LOTO

Re: Mercury 90 h.p 4 stroke starting problem

#9 Post by BassFrequency » Sat Oct 16, 2010 8:16 pm

worst case senario, some of those symptoms smell of a failed ECM. I know on Etecs the trim and all motor power is run through or supplied from the ECM.

24' 1989 Starcraft 23.1mph gps
60HP Evinrude
'96 GMC Jimmy "The Demon" custom 8 ball lever 4x4
no muffler or cat. just strait to the back

Image


User avatar

Parasympathetic
Posts: 1785
Joined: Mon Nov 19, 2007 4:48 pm
Location: Missouri

Re: Mercury 90 h.p 4 stroke starting problem

#10 Post by Parasympathetic » Sat Oct 16, 2010 9:30 pm

In your last picture, the green circled area has a Pos cable end AND a neg cable end laying up against a bulkhead. Have you been hooking that one up? Easy to miss................

Image

2015 Ranger RT175
Yamaha 70hp
Lake Wappapello, MO

IF WE MAKE GUNS ILLEGAL, THEN NOBODY WILL GET SHOT ANYMORE. THAT'S HOW WE STOPPED EVERYBODY FROM DOING DRUGS.


norske5
Posts: 9
Joined: Fri Oct 15, 2010 8:27 pm

Re: Mercury 90 h.p 4 stroke starting problem

#11 Post by norske5 » Sun Oct 17, 2010 5:41 am

@parasympathetic - yep, I now am sure I have the battery connected properly. Accessories that are available without "RUN" work (nave lights, horn, stereo, lights for gages).

Neither trim switch works in either UP or DOWN positions, and nothing happens in the START position. The only common thing I can see is the 30A fuse in that circuit. Gotta double/triple check that today.

I'll also check my wiring diagrams to see if the ECM circuit is common. Not sure where that's physically located.

Guess I'm closer.... :)

---------------------
Norske5
2005 Crest 22-ft w/ 90HP Mercury 4-stroke
Decatur IL


User avatar

Ghost Rider
Posts: 186
Joined: Fri Oct 16, 2009 10:51 am

Re: Mercury 90 h.p 4 stroke starting problem

#12 Post by Ghost Rider » Sun Oct 17, 2010 6:58 am

Okay, Before you said nothing at all worked. Now you have accesories, This is good. I think you may have hooked the battery up wrong and blown a fuse. My Merc four stroke has a 20 amp fuse that blew once when my kid did the same thing. When that happened I could not get anything at all. Just like you are experiancing. I would pull every fuse and recheck.

Ghost Rider
1976 20 Foot Flote Bote
40 HP Mercury 4 Stroke
Home : Channahon Illinois
Boating on Cory Lake in MI


User avatar

Parasympathetic
Posts: 1785
Joined: Mon Nov 19, 2007 4:48 pm
Location: Missouri

Re: Mercury 90 h.p 4 stroke starting problem

#13 Post by Parasympathetic » Sun Oct 17, 2010 7:47 am

And make sure you've got a good strong battery. Wouldn't hurt to load test the battery.

Image

2015 Ranger RT175
Yamaha 70hp
Lake Wappapello, MO

IF WE MAKE GUNS ILLEGAL, THEN NOBODY WILL GET SHOT ANYMORE. THAT'S HOW WE STOPPED EVERYBODY FROM DOING DRUGS.


norske5
Posts: 9
Joined: Fri Oct 15, 2010 8:27 pm

Re: Mercury 90 h.p 4 stroke starting problem

#14 Post by norske5 » Sun Oct 17, 2010 11:13 am

I don't think this has anything to do with my issue... but it's tucked next to the starter relay within the electrical compartment on the starboard side (below the fuse holders).

Any idea what it is?

640x480 what is this IMG_2044.jpg
640x480 what is this IMG_2044.jpg (197.35 KiB) Viewed 4541 times

---------------------
Norske5
2005 Crest 22-ft w/ 90HP Mercury 4-stroke
Decatur IL


norske5
Posts: 9
Joined: Fri Oct 15, 2010 8:27 pm

Re: Mercury 90 h.p 4 stroke starting problem

#15 Post by norske5 » Sun Oct 17, 2010 11:41 am

SUCCESS!

Thanks for the help... but it was really a bonehead (but learning) experience. :oops:

Here's what I assume the deal is/was:
1. Battery went bad - when removed would not accept a charge
2. Replaced battery, but didn't hook up the cables properly
3. Once the cables were correct, was able to get the accessories to work (those not needing the RUN position)
4. Trim UP/DOWN nor START would work - so tracked it down to fuse issues
5. Found that when I'd checked fuses early on, I didn't insert the upper 20A fuse correctly - which was the issue.
It's inserted correctly and appears to have solved the problem.

Bad news - I missed a week of great autumn boating weather :(
Good news - I learned about the boat's electrical system and... I'm back in business without any service calls. :biggrin2

This forum is awesome!

---------------------
Norske5
2005 Crest 22-ft w/ 90HP Mercury 4-stroke
Decatur IL