Shift interrupt stuck when in reverse

"I was out on the water today

"I was out on the water today and all was well until i shifted into reverse. the engine sputtered and seemed to want to die. i went back into neutral and then back into reverse. Same thing.

Looks like the shift interrupt swing arm does not go back to the neutral position when in reverse. When i go into forward, the arm swings to the high part of the arm and hits the ignition interrupt micro-switch and then returns to the middle position( valley). When I go in reverse, it moves to the other high position, but does not return to the middle neutral position. So, the micro-switch is still engaged and is cutting off the engine. I spent about two hours checking all the connections and read and re-read the service manual line-by-line and then checked each part of the shift mechanism via the manual. Still does not return to neutral. FWIW, the swing arm is not binding up.

I'll give it another look when it cools down here in Boston, but i thought someone out there might have a tip or two on this one.

tnx,"

"ok, i cooled down (quite

"ok, i cooled down (quite literally - temp down to 92) and had a cold beverage. I went back and started from the beginning. The cable from the throttle is spot on - the microswitch (the other one) hits the cam right in the middle (per spec). I then calibrated the "forward" shift interrupt by shifting into gear (per manual) and making sure the trunnion lined up properly. Then I put it in reverse and continued to follow the manual. When I was done, the forward motion tripped the switch and the arm returned to neutral. When I went into reverse, the switch was tripped and the arm did not return to neutral position. As I left it, the switch's arm is sitting on the high part of the arm. Time to call it a day."

Sounds like a bad shift cable.

Sounds like a bad shift cable. Need more info on year motor size and which outdrive.

"yea, sorry - heat stroke.

"yea, sorry - heat stroke.

1990 OMC Cobra 3.0L - 302BMRPWS.

when you say "bad shift cable," do you mean from the shifter to the engine or from the engine to the outdrive?

i watched the action very carefully just before I quit for the day. When engaging in forward gear, the roller that "rides" the arm goes up the side of the "bump" but never gets to the "crest." However, it is enough to push in the micro-switch. On the other hand, the reverse function moves the roller all the way to the top of the "bump" and, of course, engages the micro-switch. the problem is that it does not return to the "neutral" position. So, the action is asymmetrical. I would have thought that the movement side-to-side from the neutral position would be the same. I will take all input and then consult with my brother (half owner). If we can't figure it out, I guess we're off to the shop. I don't have the time to pull the whole thing apart. Cheap solutions welcome! tnx

tnx"

"Did you notice whether you ha

"Did you notice whether you have a red or black shift cable? There were problems with the originals, but not sure what years. The fix was the newer designed red cable. However, it sounds as if the one you have is sticking and won't move in the direction for reverse. You may be able to lube the cable and work it back and forth to free it up. I am sure someone with more experience will chime in here and help you out.

Jack"

Sorry cable from engine down t

Sorry cable from engine down to the outdrive leg.

"Like Jack says the most likel

"Like Jack says the most likely culprit is the lower shift cable going down to the outdrive. What I don't get though is why the other switch (overstroke) isn't doing it's job, the arm has 2 cams on it, one for forward and one for reverse, in either gear these cams move and hit the overstroke switch who's job is to disable the ESA while in gear, unless your ESA has been replaced with the newer version that has a built in timer that goes for about 6 or 7 secs and then times out and shuts off the ESA, These newer ESA's don't use the overstroke switch although most people left the switch and wiring in there)"

"I had a similar problem. The

"I had a similar problem. The culprit was the tip of the overstroke microswitch has a rubber cover that had worn off from the cam striking it. without the rubber cover the cams did not come in contact with the switch tip. Replaced switch and it was solved. You can test microswitches with an ohm meter to see if need replacing. That procedure is outlined in original omc manual. I did notice that my load lever (arm where interupter switch roller rides in) would stick more in the up position. I removed interupt microswitch, and removed the arm an cleaned and lubricated the white plastic bushings in the arm that rotate on the shaft.Surprised how gummy they were. That seemed to free up the arm to return to center position."

"Wow - thanks for all the inpu

"Wow - thanks for all the input!

- I'll check the overstroke switch. Maybe the reverse was never working right and the overstroke switch was kicking in - and now it's failing.

- I can defiintely get into reverse. The cable moves and the dog engages (the prop locks). The load lever moves correctly and the roller rides up the "bump" - it just doesn't come back.

- All my cables are black

- when i remove the assembly so all that's left is the load lever, it moves freely up and down. I aos removed it and cleaned the shaft and lubed the bushings. I did notice that they were cracked from 16+ years, so they need to be replaced. Still, i don't sense any binding.

- I replaced the ESA a few years ago (i'm going to guess 4 - definitely within the last 5 - not sure if it's the updated version. I gave the guy the P/N of the part I had and he gave me a replacement.

- I was under the impression that my setup did not have an overstroke cam for reverse. I'll give it a look-see today. If that's been overriding a bad load level all these years, then that would explain things.

i'll keep you posted. We're expecting t-storms today, so i may not be able to get out there to work on it."

"Chris if it was within 4 yrs

"Chris if it was within 4 yrs you could very well have the newer ESA unless the dealer had old stock laying around. The to tell is trace the blue and black wires from the switches back to the 4 pin connector, now look at the connector from the ESA side, the old style will have a blue and black wire plus a blue jumper to make the 4 pins, the new style only has 2 wires coming from the ESA (a blue and a black) I think."

"good morning Bob.

My modul

"good morning Bob.

My module is PN 987566. It has four wires coming out of it: black, blue, purple and white. the black and blue attach to one connector and the purple and white to another. the ESA side of the black/blue connector does not have a blue jumper - just two white plugs (where the jumper used to be?)

Also, I only see one overstroke cam on the shift arm. Would this suggest that the overstroke switch is only in play in forward gear? If so, then reverse would rely entirely on the interrupt microswitch.

So, I'm still not sure what to do next. Is the fact that the bar is not returning to neutral a sign that I have shift cable prolems? If I have the newer ESA, is it failing to shut off after the timeout period? Do I replace that? (expensive part!) So many questions - too few answers! Problems like this should emerge in October, not late June! Arg."

"oh, it gets better. I found

"oh, it gets better. I found the paperwork - i bought the ESA in 2002. Note on the installation paperwork says NOT to remove the overstroke switch, as it is used for adjustments. This suggests that the switch is not used, which is backed up by the lack of a jumper wire. BTW - my old unit has the jumper wire (for some reason, I saved it).

Now, OMC PNs are driving me nuts. My original ESA PN was 986610 (which, BTW, does not correspond to my IPB/parts list catalog). The dealer gave me an updated version with PN 987878, which is on the invoice and on the bar code sticker I saved from the plastic bag. Why the unit has 987566 stamped on it is a mystery to me. Maybe the base unit is a 566 and it becomes a 878 when some mods are made. For instance, my setup is a two-plug - I see some that are one plug only. Dunno

So, I'm sure I have an updated ESA. I'm sure that the interrupt microswitch is working (I manually trip it and the engine starts to stall). I'm sure that the switch is tripping the engine when i engage in forward gear. I can see the arm move the roller, which in turn activates the switch. I'm sure that the switch is activated in reverse gear, as that's the original problem - it stays on the "bump." I can tell you that I have not tested to see if the ESA times out after 6 or so seconds. The engine shakes so violently when that switch is pressed that I immediately take it out of gear. Six seconds seems like an eternity before that override kicks in.

My head hurts."

"Sorry for interrupting but:

"Sorry for interrupting but:
The arm where the shift cable end is attached (from remote) should have two pins, one adjustable, that activates the over-ride switch. One pin when going into forward, the other when going into reverse.
Do the following test:
Start the engine in neutral - carefully lift the arm of the cut-out switch (to engage it)= engine should partly cut out. Then with a small screw-driver: push IN the over-ride switch (cut off switch engaged)= the engine should run stable.
If this works, the module is OK and the switches ok BUT: check that the rubber tip of the over-ride switch is not dammaged. If the rubber is damaged You may try to put a plastic hose on the engaeing pins on the arm to compensate. (only a temporary solution until You may get a new switch).
To adjust the system so the over-ride switch ends at the bottom of the cam (not engaged) both in forward and reverse is close to impossible. You must have the override switch working.
Providing the shift cable from bracket to transom is correctly installed or has not been dammaged/streched, the rest of adjustments is done inside."

"Morten,
Not sure what you me

"Morten,
Not sure what you mean by pins. My cable from the shifter comes in at the top and the book tells me to adjust it so that the cam on the arm lines up in the middle of the override switch. This is done with the linkages in the "forward' position. The manual makes no mention of an adjustment in the "reverse" position. It's spot on (I had not removed it), so i went on to the the next step of checking the interrupt swing lever. I will try the override switch test that you suggest and I'll report back."

"ok, progress - at least in my

"ok, progress - at least in my learning of the system.

Per Morten's suggestion, I tested the interrupt and override switches. The override does not stop the interrupt, but that would make sense if i have the new ESA, right? Override is disabled and replaced with a timeout. so, I let go of the override and held the interrupt switch down. After about 4-5 seconds of a bucking engine, it did indeed time out and the engine returned to normal. I tried this in forward, but one would expect that it will also work in reverse. So, I guess if I had waited long enough, the ESA should have timed out when I had the original problem on the lake.

Still, I think you all would agree that I need to figure out why the arm is not returning to the neutral position. Then I wouldn't need the timeout - which i guess is just a backup - not a primary path to shut off the ESA.

I now need to wait for another pair of hands, as the manual has me putting the unit into gear while rotating the props - a bit of a stretch for me!"

"Yes Chris...it definitely sou

"Yes Chris...it definitely sounds like you have the newer version with the timeout and you are right that it's more like a failsafe mechanism and really shouldn't have to time out to disengage the ESA, you still have a problem with the lever hanging up going into reverse, my first guess would be that the cable is binding going in that direction causing the lever to hang up, you may be able to make it better by going through the adjustments? I know what you mean by shifting into gear and turning the prop to ensure engagement, dam arms just aren't long enough."

"ok, back from another 1 hour

"ok, back from another 1 hour marathon (I sound like a DJ). More progress.

I started from scratch and cleaned and lubed everything. I followed the book to the letter and it looks like the reverse interrupt is now returning to the neutral position. It's the change that has me scratching my head. The manual has you adjust the trunnion after putting the drive into forward. Done. As I've mentioned, that has never been the problem - it trips the switch and returns to neutral. Then the manual has you get the boat into reverse (I found a trick!) and adjust the sliding nut/bolt on the shift lever. Since I've had the boat, I've never touched this and the nut/bolt was about 2/3 of the way down (towards stern) when I started this whole fiasco. If you look at the photos in the manual, you'll see that they have the nut/bolt about 2/3 back - that's what mine looked like. Now, I adjusted it per the manual and it's almost all the way the other way - towards the bow. Big change. If I move it any further back, it puts pressure on the lower cable, which in turn puts pressure on the trunnion, which then puts enough pressure on the arm to keep it from returning to neutral. When I move the nut/bolt back, i can actually see the arm start to torque away from neutral. Phew!

So, "adjust the trunnion on the top cable," I hear you cry. Well, I did go back and make sure that the overstroke button was smack dab in the middle of the cam. That's the adjustment, according to the manual. I can certainly pull the cable back via the trunnion adjust, as the overstroke switch is not in play at this point.

I guess I just need to get out on the water and see what happens.

As for the shifting trick, I managed to spin the prop and use a stick to push down on the shift lever to get it into reverse. It takes very little effort, so I'm fairly certain there is no binding between transom and LU.

I'll keep you posted."

That's good news Chris but

That's good news Chris but of course you realize the true test will be in the water when you have some load on the prop...good luck!

"You had to spoil it, huh? <[

"You had to spoil it, huh? "

"ok, stupid question time...

"ok, stupid question time...

When the manual says "pull the plastic cable guide back...to remove end play from cable" - which way do they want me to pull? Relative to what? Seems that anything that has a trunnion, etc. wants me to take out the cable play. I'm having a senior moment and I can't visualize which way i would pull to get the slack out. It's tough getting old.

tnx"

I've always pulled the cab

I've always pulled the cable end away from the trunion.

"Even with the 'new' m

"Even with the 'new' modules, I allways kept the over-ride switches working both in forward and reverse!
Due to cable play and wear, getting it to work without the 6 sec delay is next to impossible and I saw too many incidents while people were 'waiting' for the seconds to pass and reverse to work!
Honestly I find the 'new' version of ESA a safety-risk.
Suggest You put the jumper back and set it up 'the old way'."

"That's actually a pretty

"That's actually a pretty good idea Morten. I changed one of my modules about 5-6 yrs ago, I've never had a problem with it though but I don't see why adding the jumper back in to the circuit wouldn't work the same as it did with the original module."

"sounds reasonable. i mention

"sounds reasonable. i mentioned that i have my old module. I'll take a look at it, but is it straightforward to pull the jumper and install on new module? Have you done it?

I will absolutely not rely on the timeout function to solve my problem. I will continue to work on the problem until i'm satisfied that the load lever is working properly in both forward and reverse."

"Thats the right approach Chri

"Thats the right approach Chris, If I remember right the those pins should just pull out of the connector although they are very tight, I'm pretty sure you don't need an unlocking tool to push back any tabs or anything."

"yea, the jumper came out ok -

"yea, the jumper came out ok - firm pressure from the inside with a large nail set did the trick.

minor dilemma though... old connector looks like this (looking down at the silver pins on the ESA)

(top row) Black Blue Blue (jumper)
(2nd row) Blue (jumper)

new connector looks like this

(top row) Empty(plug) Blue Black
(2nd row) Empty (plug)

black is ground, so i'm guessing that the new connector is just using the other ground vs. the old connector. the "money" connector for the overstroke is the pin in the second row, which is then jumpered to the other ground on the top row.

I just wanted to check before I blow something up."

"Actually it's all ground,

"Actually it's all ground, the ground signal comes out of the ESA on the blue and goes back in on the black (or visa versa, doesn't really matter)when the switch closes. By adding in the overstroke you are just taking the output of the interrupt switch and running it through the normally closed overstroke switch before returning the signal back to the ESA."

"I have the same problem on my

"I have the same problem on my boat, but in Forward. I just got in from tinkering with it, i had it disconnected for about a week until i could solve my problem. so i went through the manual procedure, and adjusted it, and noticed that when i put it in forward it engaged, and would start to disengage and re-enter the valley-slot but not go all the way and stay engaged. so now, I put it in forward, it engages, i go into gear, and then back off the throttle a bit, just to push it back into the Valley, and disengage it, then i'm good to go. weird eh."

"ok, everything seems to check

"ok, everything seems to check out on land. both forward and reverse now activate the switch AND return to the neutral position. I've verified that the clutch dog engages both in forward and reverse by turning the prop and going into gear (engine off per manual). Both lock solid, so I'm comfortable that things are adjusted fine. Next step is the water.

One last thing before I hit the water. As the throttle was disconnected during the shift adjustment, I decided to make sure that was adjusted per spec. I followed the manual, although the "pull to take out the slack" always confuses me. I can tell you that, if i hold down the throttle with one hand, I cannot move the black plastic end that sits between the throttle end and the trunnion. I think this means I have no slack in the cable. Dunno. Nothing seems to bind. One observation: while I never noticed this before (funny what you miss), I am noticing that the carb throttle does not move when i push the shifter into the first indent (ie. engage forward gear). I do get more RPMs once i continue forward past the indent. I guess this seems intuitive - don't want engine rev'ing up while engaging into gear, but just wanted to check. Is this ok?

I hope to make one final "good news" post soon. Based on some of the other topics, we all need some good news!"

"[b]I am noticing that the car

"I am noticing that the carb throttle does not move when i push the shifter into the first indent (ie. engage forward gear). I do get more RPMs once i continue forward past the indent. I guess this seems intuitive - don't want engine rev'ing up while engaging into gear, but just wanted to check. Is this ok?

That is 100% correct...good luck with the in-water test (remember to keep the fibreglass side down)

"