Not sure when Merc started using a slave relay as part of the switching circuit. Mine failed 1st year I had it & started acting up again this year so I replaced it again. Same symptoms you are having.
Mine is mounted directly behind the TBI, yours may have this or a carb.. Mounted on a stainless plate with 4 wires. 2 of these have an angled connector that fit over a couple threaded studs.Small relay, maybe 2-3" long. It's a cheap & easy fix if this is the cause.

 

Battery ? most electrical problems start there

 

My comments mirror the one's that Steve made, it sounds like the starter solenoid. On my boat it is under the Mercathode controller. It took about ten minutes to replace and cost less than $20.

 

OOPS - I just looked at my photos of the engine prior to removing it and I believe I have found it "WATSON" . I will check this device tonight!

 

yep slave solenoid on the top of the engine... cheap and easy fix

 

I would start by cleaning the battery terminal connections. This sounds a lot like some oxidation of the battery posts. When your done, coat them with Vasoline to prevent further corrosion. Also look closely at battery cables, they can be NG, even when they look fine. Corrosion gets down inside cable and is not readily apparent.

 

+1

 

Thanks for the feedback - So far I checked the wiring schematic and do not have anything like you are describing on the engine. Now of course I have a solenoid on the starter, but I don't see an auxiliary relay on the motor. Do you guys know for sure on the 7.4 MPI it's there? I will look around some more tonight, but I know for sure there is not one on the motor since I have already pulled the motor once. I have also removed the battery cable and cleaned all the connections to the starter for both the positive and the start wire. There is a fuse of some sort where the battery cable connects at the starter and this connects to the starter solenoid. I am wondering now if this could be causing some issues? I actually replaced the terminal on the solenoid wire (soldering it to the wire) thinking this was causing the problem but to no avail. I was thinking that the battery connections were ruled out since I clean them every year and this week I switched to "both" batteries on my switch and nothing changed. I will double check that though. The click I hear doesn't sound like the starter is engaging and losing power though. I will re-visit all these suggestions- keep um coming if you have had the same symptoms. Thanks -Mark

 

Don't forget when checking battery cables that the ground wires connect to a grounding stud on the engine block - remove/clean/reinstall with dielectric grease too!

You probably do have a slave solenoid (relay) somewhere with other electrical relays somewhere mounted on the engine. This allows the ignition switch to have relatively small, low current wiring that runs to the slave. When the ignition wire is powered it causes the solenoid to connect larger sized/higher current wires that go to the starter. Your ignition switch simply wouldn't be robust enough to handle the current required wired directly to the starter.

Good luck!

 

You probably do have a slave solenoid (relay) somewhere with other electrical relays somewhere mounted on the engine...........Good luck!

If anybody has my set up and has this relay please let me know where to find it. I have the SeaRay wiring diagrams printed out and it is not shown to have one. I have the mercruiser manual however and it shows one in their wire diagram but I don't see it anywhere based on the picture shown. I truly don't believe I missed seeing it after looking so many times, but I was hoping someone with my type of boat and motor might chime in here. I won't post the pic of the harness as its a PITA downloading it but I am now stumped. I will be bringing the test light with me this week to diagnose further - wish me luck.

 

Sterndirves.com lists part number 96158T as the remote solenoid for the 1999 7.4 MPI. It looks like this:

 

Sterndirves.com lists part number 96158T as the remote solenoid for the 1999 7.4 MPI. It looks like this:

Well - I finally found this relay! I decided to put the test light on it while my wife turned the key and of course it starts without the click. We repeated this ten times with the same results. I decided to look at this relay in my hand before buying the replacement (in stock locally). When I put the wrench on the top stud nuts they were loose! So loose I could remove them with my fingers only. I can't believe the nuts did not fall off. I pulled it out anyway and everything is spotless. I wire brushed everything anyway. I re-installed it and we tested this twenty times with the test light and the starter wire disconnected so the engine would not turn over during this process. Tonight, it starts every time. Now the real test will be to invite people for a ride I may need to buy the relay but having these nuts so loose tells me to see first if this basic was the root cause. Thanks to all who steered me here - I'll update this after the weekend - Mark

 

Good to hear you found it. When everyone learns to check wires and connections every time they hear the dreaded 'click' the parts places will be crying due to a drop in sales.:smt043

 

Well done, I expect that tightening the nuts will solve the issue. If it doesn't, you know where it is and the part is under $20.

 

I have the same exact issue on my 99 5.0 MCM. Click, click, click, then finally start. Once started it will always start on the first try. The shop said the solenoid gets a bit of rust on it from sitting and then will be ok for the rest of the day/weekend. I'm told a new starter is about $160 plus 3 hours labor due to the access. Is there any way to know if I have a similar remote solenoid?

 

Go to http://www.sterndrives.com and click on Mercruiser parts and then "Mercruiser and Mercury Outboard Parts Lookup". Put in your engine serial number or select your model. That will give you diagrams of your engine and outdrive with part numbers.

 

I saw the pic, I just didn't know where to look. My eyes kind of glaze over when I lift the hatch and look. I went ahead and ordered one from Amazon for $17.00 and I'll have it tomorrow. Thanks for your direction... kind of important for things to fire when you turn the key.

 

I'm glad that i could be a little bit of help, you have the hard part to do. I hope that solves the issue.

 

Look around the intake manifold and see if you can find the red reset button. It will probably be horizontal from starboard to port. Mine was right next to it, they share a mounting plate. The Mercathode blue controller is on top of it and there is a plastic wire cover on the studs so I missed it a few times. The plastic protects the two red wires from shorting since they must be high current. Be careful because one is HOT! Shut your batteries off before changing it.

good luck - mark

 

I found my relay attached to the intake just behind and to the right of the carburetor. As far as mechanical things go this was as about as simple as they get. I detached the old one and moved the wires, one terminal at a time, to the new solenoid. I removed the flash suppressor, or whatever the metal air filter thing is called, to give me better access over and around the carb.

Note to self... ALWAYS plug the top of the carb with a clean rag if you are working with anything small enough to fit inside. Yeah, one of those little brass nuts magically jumped out of my fingers, assumed a vertical trajectory, and very cleanly landed inside said carburetor. Clink! Oh sh........ It took me a few minutes to get my body in position to work on the solenoid, very carefully laying all the right sized wrenches within tactile reach.

Now I have to work my way back out and peer down inside the barrels. Those things go down a long ways. The bolt couldn't have landed on a shelf near the top, nope... all the way to the deepest depths. Luckily I have an antique magnetic probe and retrieval was much less eventful than delivery.

Solenoid replaced, all parts back where they belong, water to the muffs and perfection in starting, multiple times.

Thanks for all the pointers!

 

ok, so this post is 6 years old but today It saved me a trip to the marina service department and most likely an inflated bill. Thank you to all who responded long ago. I diagnosed the click today with a jumper and I believe it's the solenoid $30 should do it

 

Funny you bring this up so many years later-this year I started experiencing the same thing AGAIN. I realized I never installed the solenoid I bought years back as I figured the loose connection was the issue but I always kept the new one on board. So I ended up changing it before she hit the water and it's been perfect ever since. Good luck with your repair.

 

It did the trick no more click click click