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OMC Cobra ESA switches

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jbash27

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"Good morning all! I currently

"Good morning all! I currently have the outdrive off my 1988 5.0L OMC Cobra so I could replace the bellows and do a shift cable adjustment. My question is which switch on the shift bracket does what? I see that the switch with the small button switches as soon as the shifter is moved, I assume that is the one that acctuates the ESA. But my manual says that is the "overstroke" switch? The other switch with the long arm (book calls that the interrupter) doesnt move unless I disconnect the remote cable and manually move the transom shift cable all the way in either direction. So which is which and what are their functions? Thanks
"
 
"Book is right, looking at the

"Book is right, looking at the pic below the switch with the long arm sitting in the valley of the V-shape notch is the interrupter (on the left), the other with the little button that gets activated by a cam on the shift arm is the overstroke (on the right)
293390.jpg


You can manually trip the interrupter by hand but the only way to do it for real is having the boat in the water in gear and then shift into neutral, the resistance on the shift cable to separate the gears is enough to cause the v-notch arm to move the switch, engage the ESA, stumble the engine, separate the gears and before you know it your in neutral (or so the the theory goes)"
 
So what is the overstroke swit

So what is the overstroke switch doing by getting tripped everytime you go to forward and reverse?..... Also the interrupter only trips when you go from in gear to neutral? I thought it activated the ESA to help it go INTO gear from neutral? Wow Im confusing myself!LOL
 
"ok...first of all the overstr

"ok...first of all the overstroke switch is kind of like a safety net. The 2 switches are actually wired in series with each other but the interrupt is a NO (normally open) switch and the overstroke is a NC (normally closed). The overstroke actually disables the ESA (when you are in gear) and prevents it from accidentally activating while in gear.

For the ESA, it's main job is to make it easier for you to come out of gear...trust me you need it. You read many threads on here where the ESA is not working and the boat owner has to practically stand on the gear shift to get it out of gear and then usually what happens is they are pulling so hard they go right from fwd into rev...not good!

Going into gear should be no problem, just make sure your idle is low enough, around 600-650 in gear. Have a look in your manual at the wiring diagram for those switches, you will see the jumper in there that ties them together."
 
"The 600-650 is in gear in the

"The 600-650 is in gear in the water, it needs the load of turning the prop through the water. So either out in the lake in gear or tied securely to the dock and in gear."
 
Hi Bob Hill.
I'm new here

Hi Bob Hill.
I'm new here but having the same trouble as many describe withthe esa. You seem to have the best understanding of the system. I understand the basics concepts of the system. so... I have an 88 cobra stern drie that has been re-powered from 4cyl ford to 1984 3.8 chev omc. with points.
Very hard to shift and get no reponse when try to manually activate esa will re test switches to b extra sure. I read in another forum about people re-wire like a merc. they say to use the interupt switch only go to ground on one side and to go to coil neg on other this will cut all ignition rather than stumble the engine. Is it really taht simple. Can a micro switch handle that? thanks. Look forward to you good advise.
 
Hi Bob hope your still out the

Hi Bob hope your still out there some where.
Thought I had good understanding but what a loop when I started to trouble shoot the switches. think interrupt is bad as it always shows continuity(after I realize there must be a break in the lead as I need to wiggle the wire to get reading and hold in a particular position) and now I find that the overstroke has continuity only while depressed. I believe this to be the opposite of what is norm.
Also the arm on the interrupt goes from the valley to the peak when in gear. Should it stay on the peak(closed)while in gear or should it go right past and open allow the switch to open again.(momentary closed) mine looks the same as the picture you posted for Jake.
Thanks to anyone that can help. Please.
 
"Hi Chris....I just replied to

"Hi Chris....I just replied to your email. Those 2 switches are opposite of each other in that the Overstroke is wired through it's NC (normally closed) points and through NO (normally open) points of the Interrupt switch. You can pull the 4 pin connector apart and do your continuity testing from there.

When you shift into gear the v-notch arm might bump the interrupt switch but if it does it should only be for a split second. The roller on the switch should never be riding up on a peak, always down in the valley. It normally should only hit a peak for a second while going from gear into neutral. You have a problem with yours, could be adjustment but my money would be on the lower shift cable being sticky (need replacement?)."
 
Thanks Bob....ya kinda strange

Thanks Bob....ya kinda strange turns out the interupt switch works mount screw was to tight binding the switch but still has poor conection in switch so gotta wiggle wire. retested the over stroke and is complete opposite of what should be needs to be presed to be closed. thought was maybe prev. owner replaced with wrong one but looks like original wire right to harnes. tried to jump the wire in harnes to esa still no result Guess need new switch and esa required.
About the roller in the valley.it sits good in neutral. I was checking this without engine running as I was alone in the driveway. Does this make a difference? And i am not sure about the normal action of the shift plate does the roller rise up the slope then back to the valley or right over top to nest valley while in gear mine seems to go to fixed points an stay there then only return to the valley when in neutral. Mine looks like the one in pic above just mounted flat up by the left side of the carb. Sorry not up to speed on shift cable yet but will learn fast I bet. If cable was sticky would i not feel it it the lever move real nice whan not tryin to get out of gear or motor is off.
 
thanks for the link chiefalen

thanks for the link chiefalen
did not know the lower cable had a dual kind of action thought it was fixed cable guess mine is stuck not sticky it does not return the plate to the center at all only in neutral.
Hey Bob I see your in the gta as well Know any omc shops I can trust. Im in the east end? Think this might not be the best drive to take my first shot at. Seems adjustment is real critical on these and this one seems to be in good shape except for cable and esa. want to keep it that way.
 
Thanks Bob that is close enoug

Thanks Bob that is close enough for me I'll go down today and get some estimates....then go to the bank for loan. Hope not too bad. Thanks again everyone will let you know how all works out.
 
Boat is in the hands of the pr

Boat is in the hands of the pro's now will have report in the morning. Fingers crossed just need adjustment and new esa. went to glm today there aftermarket parts catalogue is awesome parts breakdown and pictures are real good. Price on shift cable is well below 50% of what dealer quoted.
Wish me luck.
 
"Hi Mr Hill, got the shift cab

"Hi Mr Hill, got the shift cable done just need to replace switches. the tech says the ESA is good just need new switch setup. Not sure what i did wrong to test the system i get no response when i by pass switch. Tech also says the overstroke switch is good but if i test it it still is normally open (NO) switch is quite clearly marked (NO),(NC) and (C) with the wires at (NO) and (C) did i miss something in the manuals that some of these are wired diff. But as I said to the tech (after he took my money and would not explain where i was miss understood) I'm just a bus driver what could i possibly know.
Any thoughts on this switch. I think I scrap both and get new ones.
Thanks for all you advise everyone."
 
"Hi Chris....what I said befor

"Hi Chris....what I said before goes, the Interrupt switch is NO and the Overstroke is NC.
Now lets make sure we are talking about the right switches. The Interrupt has the arm on it that rides in the v-shaped notch. The Overstroke switch only has a small plunger sticking out through a rubber boot. I actually went and pulled my spare out and it's only got 2 wires, attached at each end of the switch, the NO contact is in the middle and is removed. Looks just like the one in the pic below, just to be sure I've put a red circle around the overstroke.
334638.jpg
"
 
"Thanks Mr Hill. Yes I do hav

"Thanks Mr Hill. Yes I do have the same setup as in the picture and yes my overstroke switch also only has two wires, but on mine the NC wire is the one that is removed. the switch only shows continuity when the button is depressed. I have studied the switch it shows no sign of tamper and appears to be the original (cherry). Wondering if you can give model numbers off your switches mine worn off. I have contacted Cherry they say they may able to match replacements with original model numbers."
 
"Yes...you can get those switc

"Yes...you can get those switches directly from Cherry. But you know it really sounds to me like someone has put an Interrupt switch in place of your Overstroke switch but removed the roller arm?

I can't really see much in the way of PN's on the switch but took a pics to show you. On 1 side it says 11-97 and then E72 SAEJ1171 Marine which just means it's approved for marine use. You can see Cherry stamped right into the plastic, on the other side all you can see is cherry. You can see the NC in the bottom left and the C in the bottom right. I don't have an Interrupt switch to look at but the one wire should come from the middle of the switch NO and the other from the C.
334649.jpg
"
 
"Great pic. Mr.Hill, I believe

"Great pic. Mr.Hill, I believed the switch to be original but never thought of someone removing from harness as show in your picture(pins and all) I assumed they would cut and solder in a new one. Here is a pic of my switches. You can see the overstroke has no place to mount the arm so eliminates the possibility some one removed but clearly someone done something wrong here. Do you want to sell your switch?
334656.jpg
ESA Switches
 
"Chris...do me a favor and dro

"Chris...do me a favor and drop the Mr. Hill part (starting to get a complex and your making me feel really old) Bob works just fine, thanks.

Your right, your 2 switches are definitely different, wouldn't have believed except to see it.

Sure...I'll sell you mine if you want. But beware these things are not cheap, I paid around $60 a piece for mine several years ago. The little rubber boot tore on one of mine causing the plunger to stick in sometimes, it was a hard problem to find but I bought 2, one to replace the bad one with and another for a spare. Of course you that when you buy a spare anything for the boat then you will never need it
lol.gif
The OMC PN is 982767, you can give good old Klaus Marine a call to see what they go for now but I'll give you this one for $25 (plus shipping or maybe we can mail it?)


ps...if Andrew reads this post...sorry if this transaction goes beyond the forum rules, not trying to compete with you!"
 
THANKS EVERYONE INVOLVED THIS HAS BEEN A VERY HELPFUL THREAD. I tried setting up per hastings notes and I did so incorrectly because when he spoke of rocking upward stiffly and downward easily I didnt know he was speaking of the load lever that the interrupter switch rides on, I thought he was talking about the throttle handle:eek:, so no wonder my boat hasn't been running right in gear!!!! MANY THANKS
 
Glenn987 said:
Hello,


Can someone tell me how to adjust the overstroke switch withe the two cams?

thank you very much
Click to expand...

No. I can tell you what I did. Disabled the complicated and useless ESA entirely. Cut the wires to the micro-switch (the one with the arm that rides in the V-notch) and connect one side to coil negative and the other to ground. Adjust (bend) the micro-switch arm so that it engages the switch at the upper most*travel on the V-notch when shifting.

Did all this AFTER doing the Stuart cure.

Further work could include a switch on the control panel that enables*and disables the shift interupt altogether.**


Not saying this is "accepted", but MY problems*with this pandora box are OVER.*After TEN years fighting the ESA plague, I'm now a happy boater!!

IMHO, the OMC Cobra outdrive was the best built in its time. OMC*management hired*losers to make that drive function properly.*
 
widi59 said:
No. I can tell you what I did. Disabled the complicated and useless ESA entirely. Cut the wires to the micro-switch (the one with the arm that rides in the V-notch) and connect one side to coil negative and the other to ground. Adjust (bend) the micro-switch arm so that it engages the switch at the upper most*travel on the V-notch when shifting.

Did all this AFTER doing the Stuart cure.

Further work could include a switch on the control panel that enables*and disables the shift interupt altogether.**


Not saying this is "accepted", but MY problems*with this pandora box are OVER.*After TEN years fighting the ESA plague, I'm now a happy boater!!

IMHO, the OMC Cobra outdrive was the best built in its time. OMC*management hired*losers to make that drive function properly.*
Click to expand...





Thank you for your answer. I also thought about your way. You can even make a manual switch to activate the interrupter. But i want the original way :)
I can use my gas handle when my engine is running. But when my gear is in the reverse state there this no power for gas because the interrupter switch is still activated. Maybe i can try to adjust the overstrike onces to overbright the interrupter
switch. In the manuals i can't find anything useful with some pictures.
 
Glenn987 said:
Thank you for your answer. I also thought about your way. You can even make a manual switch to activate the interrupter. But i want the original way :)
I can use my gas handle when my engine is running. But when my gear is in the reverse state there this no power for gas because the interrupter switch is still activated. Maybe i can try to adjust the overstrike onces to overbright the interrupter
switch. In the manuals i can't find anything useful with some pictures.
Click to expand...

Your system is out of adjustment. When you are in gear, the ESA should not activate. Trying to adjust the overstroke switch to compensate for this is not the solution. See the site below.


http://www.hastings.org/~stuart/cobra/
 
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