1990 Chris-Craft Concept 4.3 OMC Cobra PLEASE HELP

Seaward10

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Jul 31, 2024
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I hope that I can get some help, while also providing a laugh.
My engine will not turn over. The boat has been in my wife's family for 20 years and has always had issues. The ignition switch has always been loose and spun around when turning the key. I told my wife that this should clearly be fixed after I had turned the key and nothing happened. I had looked under the console and only two of the wires (I believe it was the battery and starter wires) were connected while the other was just dangling there. I reached in and accidently touched the dangling wire to the other connected wire and it started... basically hot-wired the boat by accident.

Prior to this, the boat would die at 3000 RPMs in which I had fixed it with replacing the fuel pick-up line and anti-siphon valve. After reattaching the wires to the ignition switch, everything was fine with the exception of the engine turning over. I checked the spark plugs, fuel filter, backfire flame arrestor, exc. and all were fine. Everything was great after I changed the fuel pick-up line and before I accidently hot-wired the boat.

Any/all advise would be greatly appreciated.

-NC
 

Seaward10

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Joined
Jul 31, 2024
Messages
8
I hope that I can get some help, while also providing a laugh.
My engine will not turn over. The boat has been in my wife's family for 20 years and has always had issues. The ignition switch has always been loose and spun around when turning the key. I told my wife that this should clearly be fixed after I had turned the key and nothing happened. I had looked under the console and only two of the wires (I believe it was the battery and starter wires) were connected while the other was just dangling there. I reached in and accidently touched the dangling wire to the other connected wire and it started... basically hot-wired the boat by accident.

Prior to this, the boat would die at 3000 RPMs in which I had fixed it with replacing the fuel pick-up line and anti-siphon valve. After reattaching the wires to the ignition switch, everything was fine with the exception of the engine turning over. I checked the spark plugs, fuel filter, backfire flame arrestor, exc. and all were fine. Everything was great after I changed the fuel pick-up line and before I accidently hot-wired the boat.

Any/all advise would be greatly appreciated.

-NC
 

kenny nunez

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Jun 20, 2017
Messages
3,289
The start wire is the yellow/red, the ignition should be purple and as you already know the battery wire is red. If you remove the switch the backside should be marked B-bat, s-start & I- ignition.
Do this and be sure that all the wires on the backside of the instrument panel are tight.
 

Seaward10

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Jul 31, 2024
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The start wire is the yellow/red, the ignition should be purple and as you already know the battery wire is red. If you remove the switch the backside should be marked B-bat, s-start & I- ignition.
Do this and be sure that all the wires on the backside of the instrument panel are tight.
Thank you for that, Kenny!

I did make sure the wires were in the correct spot after your message. The next day I had switched the battery on and tried to turn the blower and bilge on but both were not able to turn on, along with the engine. Trim works though. I only touched those three wires (red, yellow/red, and light purple).

Would this be a fuse situation? Ignition starter? I can take a pic of the wires under the console later if that will help.

Thanks!
 

Seaward10

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When key is turned to ON nothing happens, gauges don't energize, etc , correct?

If this is the case look for the 90 amp fuse on the starter post, it's square looking thing. See if you have Battery voltage where the Red/Purple wire connects
https://www.connollymarine.com/MerCruiser_90_amp_Starter_Fuse_Assy_p/qc-8m0207795.htm
When the key is turned on, the gauges (fuel, volt, temp, exc) do work. None of the accessory buttons (horn, bilge, blower) turn on. The engine wants to start but never gets over the ledge without me feeling it will flood.
 

alldodge

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My engine will not turn over.
ok, when you said it won't turn over (motor cranking) you mean it won't start, it will crank

None of the accessory buttons (horn, bilge, blower) turn on.
Look under the helm I'm thinking either a wire was either missed and not put back on the key switch, or one may have been put on wrong place

There will be a 15 to 20 amp fuse behind the helm and many times is a inline fuse. Normally when this fuse blows then there is no power to the key

Turn key ON and measure voltage at the coil
Check for spark at a spark plug
 

Lou C

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Nov 10, 2002
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12,649
Cobra doesn’t have the fuse on the starter solenoid like Merc but there are 2 large 50 amp fuses in a rubber fuse holder near the big cannon plug. The rubber fuse holder is snapped into the back of the shift linkage bracket.
If your gauges go on & your trim works but accessories don’t something is wrong with your dash wiring.
 

Seaward10

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All great advise! I am a rookie when it comes to electrical/engine fixes, so, it is nice to have an idea of where to start before I replace every part of the boat haha. I will give it a look this weekend.
 

Lou C

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Nov 10, 2002
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You will find it MUCH easier if you get ahold of an OMC shop manual with the factory wiring diagrams. That is for the engine & trim system. The dash wiring is separate, it might be available from Chris Craft, I was able to get one for my boat from Four Winns. BTW I think in that time period both Chris Craft & Four Winns were owned by OMC.
 

Seaward10

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kenny nunez

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The blower, bilge pump, lights or any other items not related to the engine’s operation are on a seperate circuit and should not be fed through the ignition switch. In other words their circuits are always hot as long as the battery is connected.
I have seen boats that had the fuse panel being fed from battery post on the ignition switch where the bilge blower etc have their uses.
This was used only as a main connection point for the wires.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Some light reading

See the bottom of the post in this sticky for a factory OMC manual


And since none of the documentation from the OMC era survived the multiple company sales of Chris Craft to the company it is today

 

Seaward10

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Jul 31, 2024
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I cannot thank you all for your boat wisdom. I did come across the fuses in the rear starboard of the engine… zero idea how to take it out/replace without totally messing things up but will do some more research haha
 

kenny nunez

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Take some pictures of the wires, label them and every thing will work.
If several wires are on the same terminal tape them together before removing them.
 

Seaward10

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Jul 31, 2024
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UPDATE - Welp, still not looking good.

-Engine will not start (clicks when turning key)
-All dash switches (horn, lights, blower, bilge, exc) will not turn on - even tested electrical wiring and replaced circuit breakers. Main battery was new as of this year
-Replaced kill switch

I did a continuity test on the solenoid and 90% sure it has no continuity, yet, the position of the solenoid is tucked back facing away from me.

Since I am not in any way, shape, or form a mechanic or electrician (this was the first time I have ever used a multimeter... that much of a rookie) if any tips can be provided as if you are speaking to a 5th grader, that would be ideal haha.

What I think could be the issue/s-
-Solenoid ?
-inline 50 amp fuse (no idea how to take off of metal bracket without thinking I will break something) ?
-ignition coil ?
 
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