Replace Mercruiser Transom Switches WITHOUT removing lower unit

Replace or Repair Mercruiser Transom Switches WITHOUT removing lower unit.
Manual: The manual shown is from Clymer and can be found at www.clymer.com/s/mercruiser-s...

[@alext5035]

Just took out an ‘86 Wellcraft 192 American with a 170HP MercCruiser w/ AlphaOne outdrive that I just purchased today and luckily everything went smoothly until it was time to head home and encountered this problem. I nursed the trailer home with trim stuck ALL the way down and had it beached on the ledge of my garage door and gravel driveway. Your video is the ONLY that saved my sanity and satiated the inner voice in my head that has been telling me for weeks that boats are nothing but hassles. Thank you SO much!

[@swalesutube]

2yrs and the repair is still working great!

[@Bymb2020]

Thanks for making this simple and explaining each piece clearly plz keep making videos...

[@geoffhoyle479]

I have a bravo 3 and replaced the trim and limit without removing the gimbal. 1/4" socket set and a I had a 5" long 1/4" spring extension bar that worked great, much better then a wobbly joint.. 11mm bolt holding the wire clamp, my clamp was completely corroded and I needed to get a new one. My bravo is 22years old. I put a bit of tape on the new wires to hold them together on the inside side and a small nylon cable tie on the outside, this also helped hold the clamp, this allow the clamp to remain in places as well. I also used a pair of long Forceps to put the bolt in and had the wife pull the wires from the inside. A little fiddle and the job was done. .Oh while I was threading the wires back in I split them down a bit so I could pull one wire first and then the other. I used a thin lashing twine tied to the old wires before I pulled them out one pair at a time. And. Put colour tape on them inside (before pulling them out) and the wires they needed to connect too inside. Many thanks, made it reflectively easy.

[@swalesutube]

Great tips, thanks for sharing.

[@austinhydroax]

Excellent video, my wires are fine but I need to clean out the switches and verify connectors and your video really helped me see what I need to do here. Thanks!

[@markjennings2315]

Interesting, thanks for posting. I also have a good sense of how it looks when you need reading glasses. Focus was a little challenged in this!!

[@BoatLakeHouseKids]

Awesome! Thank you for doing this video. I was just about to tackle this job myself wires in the same condition.

[@josephperry4344]

Excellent video, I love rebuilders instead of replacers. I appreciate your use of self modified/self fabricated tools. I love it! half of repairing is having the correct tools, the other half is the ingenuity in their use.

[@swalesutube]

Joseph Perry thanks for the comments. Glad to see almost 200k views, makes it worth the time to make these videos. Hope it helped give another rebuilder ideas!

[@natecoston1095]

thanks for sharing, I have the same problem, hope to have it fixed soon.

[@joesilverbliss1721]

Thanks for the video. Going to try it next week. I agree about mercrusier engineering. Joe

[@marioflores768]

Sounds so much sense. I going to try to find it. Thanks so much sir

[@danmeister8675]

Just finished doing this. What a pain in the you know what! Took about 4 hours - getting the bracket and bolts back on were the hardest part. Thanks though for the video - saved my self probably $400.00 in labor at a repair shop. Parts were just under $80.00 on amazon.

[@swalesutube]

The fix worked. No issues. If I get another 20 years out of these wires I will be happy. BTW the 12 volt to water comment makes little sense... You need these units to properly trim your lower unit. You are reading resistance not putting 12 volt into water.

[@onemoreboat]

I watched your video and decided to rewire my trim sending unit. FYI, I had some 12awg/3 stranded marine wire laying around and found that the black wire is a direct replacement for the original in size. Mine was a 2002 mercruiser with alpha 1. Thanks for the video!

[@swalesutube]

onemoreboat Thanks for the feedback, hope your fix goes well.

[@derekgale4917]

Every thing works except my trim gauge, now i know what to look for Thanks

[@infinexnow]

Thank you much! Great video that just saved my bacon.

[@chavocanuck]

I took the trim limit apart as you showed and found the wire is held into what the video calls the "brushes" with what looks like an allen screw but I could not find an allen key that fits it. I say it is between the 1/16" key and the 5/64" key. I tried metric too and none of them work either. If I could get the wire out, all I have to do is cut off an inch (my wire is bare at the entrance to the switch) and rewire it inside the switch.

[@andy3590]

That top bolt is very hard to get in trying it tonight for the first time. I was trying everything could not get it to start. Then it dawned on me all you need is a straight screwdriver and some sticky stuff. Now I can have it out and in in less in a minute then tighten it with a swivel socket.

[@swalesutube]

Yep, I think I did that also. You just have to get it started, then go to the wrench/socket. Glad it worked for you.

[@TimmyBunkley]

Thanks So Much For The Info

[@BigIslandMNMinnetonka]

NIce job! My up somtimes works. The gauge bounces around. I traced it back to this part. Do you think I can just pull the cap off and clean it up?. just spray some electrical cleaner untill I am ready to replace them. What do you think?

[@MrCalifornia1234]

Another idea. Put liquid electrical tape on the wires. That’s what I did after I cleaned up my trim sender. My wires weren’t that bad. Trim sender was full of rust.

[@bwestfall7281]

To start the top bolt I used about 18 inches of safety tie wire(used before the age of Loctite). I wrapped it around the shank of the bolt just below the head, brought one end up then the other on the opposite side of the bolt head. I then twisted(tight) the short end of the wire to the longer side of the wire Leaving a small tail on the short side. Using the wire I was able to feed the bolt up into the hole and get it in a few turns, I removed the wire using long needle nose pliers.... Hard to explain but worked for me 2 times.... BTW- My inboard wiring from 1968, looks just fine- the stuff out side of the Gimbal housing was trash...."experts" LOL

[@dennissytsma3561]

The 7/16 wrench fabricated to reach the upper retainer screw bolt and details about the retainer are to my mind the best part of this short video. I agree MerCruiser engineers should consider maintenance and could have located the wire pass through if they had given the trim and tilt sensor replacement more consideration. The author is better than I am reaching the bolts, I found it impossible to do this job without removal of the drive and the bell housing and the yoke. I'm opting to tear down the entire thing because I want to replace everything that might break in future while I do this job. Very good video.

[@swalesutube]

Thanks Dennis.

[@drizler]

I did that a couple years ago and it works OK. It’s only a problem if you have to operate out of the Shallow launch and have to manage to get to deeper water. If you don’t have shallow water you’re all set. Otherwise all you have to do is use the instrument to tell you where Max trim is. Then comes the problem of relying on it because I’ve been trying to get mine to work great for years and replaced everything and it still screws up. You set it and it wanders after a week or so. It works but it’s just not anything I call reliable.

[@QuantumDesignz]

Could always drill a hole right above housing into boat and use reinforced tubing to protect wire then silicone. Or! Use the same wiring and just cut/splice the trim with waterproof connectors easy done

[@fredlehman6337]

Thanks for the video and information. I'm going to try the same thing on my twin 2004 Bravo 2's. I'm hoping I only have one bolt to remove instead of the two you had. How long of an extension did you need on the 7/16" wobble head socket? Thanks again!

[@atkgrl]

Great job

[@user-lw5ik8lw4i]

A complete new switch kit is available on Amazon for $32.00 as of August, 2020. Comes with wire and the trim sending unit for the gage and the trim switch.

[@robertg.9964]

OK, I have several 7/16 wrenches since I prefer to tackle my own work before pulling in the pros. Thanks and I'll let you know how I made out on my replacement.

[@BoatLakeHouseKids]

Lamp cord should work fine apparently mercruisers wire is not coastguard approved either lol nice job again sir

[@jeffthomas1063]

If the wire is good you could cut and butt splice, use a good 3m heat shrink. To start the hard to get at bolt, I've read a small child can reach it and get it started. I have an extension cord passed on from my Grandfather, estimate it from the 50's at least, and the cord is still flexible in cold weather. Anything we bought in the last 20 years gets hard and stiff.

[@edwardmorton6730]

GOOD VIDEO and I applaud your ingenuity to tackle this project as a DIY without removing the sterndrive and bell housing. One recommendation I would like to make for future viewers who might attempt to also tackle this project themselves instead of paying a dealership or marine repair shop. SPECIFICALLY: I would NOT/NOT use LAMP CORD to do this rewiring job with. For reasons of safety and longevity, you should ALWAYS use MARINE GRADE wire (from Anchor or another US manufacturer) as MARINE GRADE heat shrink connectors on any DIY project you complete on your boat. The copper strands in Marine Grade wire are tinned to prevent corrosion (oxidation), which particularly important if you ever use your boat in saltwater. It also has high temperature silicone insulation, so if you ever get an engine compartment fire (and they are not that rare, particularly on older boats), that rubber lamp cord insulation is going to burn like a fuse when it hits its melting and combustion temperature, which may be as low as 350 degrees Fahrenheit. Silicone will get you to around 500 degrees or higher before it will light off, so that buys you at least an extra minute or two to try and extinguish the fire (with your extinguisher) before you have a major conflagration and explosion. Even the original wire that Mercruiser installed in your boat was NOT American Boat and Yacht Council (ABYC) and National Marine Manufacturers Association (NMMA) compliant, likely because of its age (1984). I do like the idea of also sheathing your new wires with heat shrink tubing (also MARINE GRADE) as an extra layer of protection against chafing and water intrusion. Marine grade heat shrink has an internal adhesive that self-seals the inside of it when you apply heat to it (so it waterproofs the wire inside it), and it too has a higher combustion temperature than the automotive stuff you get at an auto parts store or Harbor Freight. Just like the wire, it'll cost a few extra bucks to buy MARINE GRADE heat shrink tubing, but it's worth it both in terms of safety AND longevity for your DIY repair project.

[@kevineich5029]

They didn't put the wire grommets in the sides as you suggest because there would not be enough slack in the wiring to accommodate the steering movement of the drive. Even if they did run the wires where you suggest, the amount of slack in the wiring would not be able to be contained and could get damaged.

[@weldercamaro]

Hi, have you considered using a stud for the upper bolt ? then assemble the rest and put the nut on last.

[@leinie6683]

I wouldnt be using lamp cord , but thanks for showing that it can be fixed without removing the entire drive. I wiggled a new exhaust bellows in there once so I should be able to get new switches in too ! F'n engineers should be forced to pay for repairs to the shit they design

[@swalesutube]

Yeah I would have preferred something different.. maybe silicon based, but honestly the lamp cord has been fine. Its got a rubber cover and the gauge of the wire is large enough. No problems so far.

[@shawnn6926]

This reminds me of something years ago. My wife had this one car with a really bad design. The spark plugs could not be changed near the firewall. After talking to a mechanic, he said that the engineers had to design a special tool just for the removal of 2 plugs. It had 4 elbows in the wrench.

[@liveinmyamerica]

Thanks for the video and information, boat dealers screw the boating public every chance they get. I just changed a trim lift hydraulic line behind my stern drive. The boat shop wanted $250.00 for some kit that would really fix me up, I went to a shop that makes hydraulic hose and they rebuild it for $7.23.

[@davidtyner7247]

I have a 2000 Bayliner and this past weekend discovered that one of the wires on the starboard switch had broken due to corrosion. The port switch is also ready to break. When I attempted to remove the starboard switch, three of the plastic gears fell out. Does the replacement switch come with new gears? Am I able to splice the wire from the new switches to the existing wires so that I don't have to run the new wires through the transom? This would save a lot of work and head aches.

[@robertg.9964]

My boat is a 84', same issue with wires.In the end, did the swivel/ratchet wrench work for the top bolt? Thanks

[@eggbertfarnsworth5787]

Inspired by your video, I'm attempting this. Bottom bolt wasn't too hard, but top one took a lot of wrench modification. Much different than what you did. I'm now at the point to run the new wiring, but I am worried about how to get the bolts back in... specifically getting the threads started.

[@swalesutube]

Glad the video helped. Getting that bolt started can be a challenge. Do the easy one first, then the bracket is lined up for the next one. Good Luck.

[@eggbertfarnsworth5787]

I did exactly that. Tough to get it started though. I wound up taping a coat hanger to the center of the bolt head... acted like a mini-u-joint.Another tip is that I removed the nuts from the top two gimbal ring clamping bolts, and pulled the bolts back to make a little more room.Thank-you for your video!

[@Nickolaughagus]

So was this entire venture successful? Seems like the optimism a guy would have before actually doing the full job

[@swalesutube]

Yes still working

[@craigsteven7805]

I've got that same book

[@swalesutube]

Yes try to find Coast Guard approved wire as that would be best. A polarity problem? Polarity has not changed, resistance is the same as OEM, gauge is working, trim is working. I agree that these should be designed as a sealed unit, but Mercruiser engineers did not design them that way. They were not concerned about the issues being raised here. They still sell the exact same design. Actually the design looks to be made for serviceability with screw connections for wire ends and housing.... Very easy to rebuild. If anything I have reduced the amount of electrical leaking by replacing the deteriorated wiring. I already know the worst case scenario... With bare wires the gauge and trim still worked. I just did not like the idea of having bare wires. I will continue to monitor the units and report any issues... But so far so good.

[@GhostSot]

Don't sweat it. You did a fine job.

[@samiam1150]

Mercruiser doesn't want you to repair it. Mercruiser wants the dealer to repair it for you.

[@allenletizia321]

My trimer gage stop working . could be the wire to sensor ? Sensor SWITCH on right hand side of stern drive looking at it from back ? I notice there 3 wires look like s/s 1 broken . I thought it might be that 1 giving me trouble . IDK were that s/s wire goes to then

[@swalesutube]

A long extension will make it easier. BTW... unfortunately for me... I might as well have removed the lower unit as my shifter cable broke the other day. The outer cable casing broke right after the shifter bellows. I had to drop the lower unit and fix the cable at a campground... at night... So I recommend you look closely at your bellows and shifter cable. If either need fixing then just remove the lower unit and do it all at the same time.

[@fstarockaburns425]

couldnt have said it better - so many different and better ways they could have done it!!! I think a hex nut might work cos then you can get a ball head hex in there at an angle-

[@swalesutube]

Good idea with the hex (allen) bolt.

[@user-lw5ik8lw4i]

Use boat wire with the double silicone installation coating. Boat wire is tinged through out so zero corrosion. It will last a lifetime. Standard usage through out on the Cigarette boats.

[@user-lw5ik8lw4i]

Replace the two sealing screws, the hard to get at 5/16 ones with Philips head.

[@swalesutube]

Mercruiser has been using this design for over 50 years... So maybe you should bring up your concerns to their Electrical Engineers.

[@gdebrango]

Failed miserably is an understatement. I’m fighting this right now. My bell housings out and I’m struggling. lol I have a couple different things coming to try. Can you switch it to the gen 2 cover with one bolt

[@marioflores768]

hi . i have the same problem that the wires just disappeared i find two wires that go to the hydraulic motor and the one that go to the plate that you mentioned that the plate is plastic . but i still got to find where the other wire goes or is got to be join to the one making ground ?

[@swalesutube]

So it seems your Trim Limit switch is connected as you have 2 wires going to the trim motor. The Trim Limit switch basically keeps you from raising the motor out of the water with your hand (throttle) control switch.So the other wires are most likely your Trim Gauge. You should be able to look at your gauge and if it has 2 wires then you need to get the 2 wires to them. If you only have one then I suspect you just need to ground the other wire.

[@ansona705]

I have a broken wire by the trim limit unit. If you wanted to bypass the limit switch temps tilt, could you just jumper the two wires together so that your console limit switch would work, using caution obviously to not raise your leg too high while on plane.

[@josepeixoto3384]

Of course,yes; that will work ; the drive will go up , including ALL the way up; ONE has to be careful,and keep it down when underway; better late than never,lol

[@billnazarenko1716]

I thought I just might try connecting the two limit switch wires in the boat since the wires are totally shot coming through the boat

[@penttiranta9730]

Looking at these videos I found out that my limit switch on my 1992 Searay never worked. I could lift the drive all the way up with the up switch (and always thought it was supposed to be that way), and I would know when it was max up or down from the sound of the hydraulic motor. Now as I use the boat in a big lake with many islands and beaches I dont understand why anyone would want a limit on their drive unit :)

[@swalesutube]

The reason is to prevent cavitation when you are running at high speed. If you raise prop out of the water when going fast it could be dangerous as well as possibly cause damage. Most boats have two separate switches for raising the prop. One is on the handle which respects the limit switch and the other is on the dash (trailering mode) that can bring the prop all the way up

[@rockybutler]

I am sure the engineers were trying to keep the wire and clamps up as high out of the water line as possible, were you are talking about drilling a hole and going through the transom plate is a major pressure and leak zone.have you ever looked back there at full throttle? I sure the heck wouldn't want a potential leak and wire clamp there!

[@swalesutube]

If you look at the other side of the transom you will see the shifter cable goes through the same location I was proposing for these wires. They could have used the same bellows design here as well. Would save a ton of time and effort.

[@rockybutler]

True...

[@alanhillary3882]

To read resistance you have to induce a current in the meter and therefore there is voltage in the water, it may not be 12VDC but there is some voltage. Try this with two meters, the analog meter type if you can find two. Put one on resistance and the other on voltage and touch the red to the red and the black probe to the black, you will read some voltage on the meter set to read DC volts. It's very low when using a very good meter, and the gauge on the boat is not nearly as good as most basic meters.

[@frankletizia7835]

My trime gauge was working when I went out in the boat and came back the gauge was not working could this be the problem?

[@swalesutube]

Very possible. I would take the trim guage apart and possible OHM it out with a meter. Maybe simply cleaning it will fix it. You could then check both ends of the wire for continuity with a meter. That would tell you if the wire is bad. good luck

[@eldraebeytv6235]

Where did you get replacement parts

[@swalesutube]

No parts needed if you rebuild. Just clean and install new wire. Find marine rated wire if possible.

[@goodenergy718]

Just curious why marine grade wire wasn't used for the replacement?

[@goodenergy718]

But I do want to thank you for the tutorial.

[@swalesutube]

I chose the wire I used for a couple reasons. First it was all I could find locally and I needed it fixed quickly. Second is that it matched the size and groove perfectly. I think many are making too big of a deal on marine grade wire. Maybe what I used was marine grade, not sure, I picked it up at Lowe’s. It has been working fine for years. As I suggested in the video a silicon wire would work best as Mercruiser wire dries out and cracks over time.

[@dougdoug2165]

look polyurethane insulated 2 conductor wire 12 or 14 gauge. Hopefully Mercury reads this.

[@russg1801]

MerCruiser trim limit / trim sender switches - another engineering disaster among many on these freakin' drives. If it hadn't been for OMC Stringer drives with the rubber boot in the boat's transom, these would have won the prize for Worst I/O Evah!

[@russg1801]

BTW, what just about EVERY MerCruiser owner ends up doing is saying "Fug It!" and doing without the trim gauge and bypassing the trim limit! I work on boats regularly and hardly ever see a Merc I/O more than 10 years old [5 or less if it's a moored instead of trailered boat] with the trim limit still in the Bow Up circuit. They're all bypassed making the 'Trailer' switch redundant.

[@jeffthomas1063]

I remember reading somewhere, many years ago, the words of maybe an engineer (or lawyer), about these being so badly engineered that there should have been a major lawsuit.

[@caseydabney1042]

Nice boat tho

[@leinie6683]

Well, a previous mechanic did me a favor and left the upper bolt out last time it was replaced ! I would buy him a beer if I knew who it was. Im not going to try to replace it either. If it leaks a little water, Ill be OK with it. It hasnt leaked so far so I anticipate it wont after I fuckit-ahh I mean fix it up

[@leesire]

The wires that go inside the cap on the lower unit look like they are about to come out. Can I just loosen the 4 screws and insert the wires to a better position? I don’t want to take the lower unit apart. Thanks for the clip. What is the name of that manual

[@swalesutube]

The manual is the Clymer Mercruiser Stern Drive manual. You can find it at www.clymer.com/s/mercruiser-stern-drives/marine-manuals

[@swalesutube]

Unfortunately it looks like a no go on the ratchet. Honestly I did not try very hard as I already has the bolt fairly tight. Best option is to use a thin wall 7/16 wrench as long as possible. In my case I only had half of the wrench. Possibly with the open-end I could have switched back and forth between it and the closed end to get the indexing right and tighten the bolt more.

[@caseydabney1042]

For your information Lamp cord is not U.S. Coast Guard approved for use on a vessel. The guy is right you are potentially putting your boat and others at the dock at corrosion risk. You are causing a polarity problem around your boat.

[@batkataaa]

Not the only one case with poor design!!! That is the reason that i'm selling my boat. ... Shift cable bellow - the boat can sink because of 14$ part........... Amazing isn't it?

[@dwetick1]

You can see for yourself what's happening...this is electrolysis at work! Brittle wiring and conductors disintegrating after a few years service. You do not want 12 vdc going into the water under any circumstances! An EE talking...Better to get smart rather than remain stupid!

[@swalesutube]

Not sure what your point is. I agree that Mercruiser could have designed a better unit, but mine worked for 30 years before needing new wiring. Not sure if the ‘new’ versions allow you to replace the wire, but mine seemed to be built to do that... and it works fine.

[@markw5766]

Mercruiser failed period, absolute total engineering piece of shit.

[@toddpedersen1866]

mate i appreciate your attempt but you ramble on and on about everything else except what you are doing and you never actually get to the point .