ESA testing/wiring help please.

borman

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Hello from Riga. Sorry in advance for my grammar!!:)
In reference to an archived iboats topic titled Anyone know how to test an ESA switch, and ESA module? I could really use some additional help please.

I bought a 1990 Caravella with an OMC COBRA 2.4 without an engine. So I had put in 2.9 v6 ford cologne. Correctly connected it to stern, built cooled inox exhaust and done electrics....started engine and connected gauges. My problem is esa. I have all in place and all esa switches is working (technically) From original boat wires I had only two free wire connectors. (no where to connect) from which one was for tachometer. ....So I have two free wires, BUT I am not sure that it is for esa.

I had tested them, but with tester there is no signal in any way. I had read here in forum about pulsating signal, but have not tested it, and not sure if it's possible?(theoretically must)?.
Please help with this deal. Maybe with some pictures or diagrams or words :). Which wire/s goes to coil from esa???? Which wire gives what signal?????
P.S.
Soon is coming summer and project must be done :) :) :) Thanks all.
 
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borman

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esa wiring

Hello from Riga. Sorry for grammar :). ..In two words about my problem. i bought caravella 1990. OMC COBRA 2.4 without engine (at all). so i had put in 2.9 v6 ford cologne. Correctly connected it to stern, built cooled inox exhaust and done electrics....started engine and connected gauges. My problem is esa. I haw all in place and all esa switches is working (technicaly) From original boat wires i had only two free wire connectors. (no where to connect) from wich one was for tachometer. ....So i haw two free wire, BUT i am not shore that it is for esa. I had tested them, but with tester there is no signal in any whey. I had red here in forum about pulsating signal, but have not tested it, and not shore if possible (teoreticaly must).
Please help with this deal. May by with some pictures or diagrams or words :). Witch wire/s goes to coil from esa???? Wich wire gives what signal?????
P.S.
Soon is coming summer and project must bee done :) :) :)
 

alldodge

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Howdy
I'm finding the 2.9 motor was installed in Rangers and Broncos from 86 to 92. The motor was never installed in a boat and this is the issue. ESA module needs to be connected to the distributer to cause the motor to miss. This is the wiring for the OMC V8

OMC Engine Wiring.jpg

The wiring for the 2.9L V6 is below. I'm not sure about how to install it. My thought is to not use the ESA module and use the Mercruiser shift interrupter switch design instead.

The shift switch for the OMC and the Merc operate the same, the difference in connection will be the switch type. The switch needs to be a Normally Closed (NC) instead of Normally Open (NO).

The interrupter switch would be installed inline where the arrow is. This way when the shifting the switch momentarily breaks connection and the motor stumbles

Maybe bruceb58 or another OMC guy can advise

Ford 2_9L.jpg
 

borman

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Thanks for diagrams. They helps. The new engine has a ignition coil, so I think (hope) that oem OMC esa must work for mine new ignition too, but it depends of several questions..... 2_variants.jpeg
 

borman

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The red arrow wire I have taken from 2.9 engine ecu. Does it meters? I think that no.
Does pink wire will give some signal when only ignition is on? ...engine not running... I think that must...What kind of signal must come?
The blue arrow.. I have very similar esa system ( of course) but..... I have one more little box (like esa ecu, but litle smaller) wired in esa system. I am not near my boat, so i cant explore that at the moment. But I am pretty shore that I have something more...not like in the upper diagram.
 

borman

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P.S.
It takes a time for my to write in english :)
P.P.S
European ford market is different from USA. We have 2.9 engines in ford scorpio (running car costs about 300 $), but it stays very rare ( too old). We have no broncos and other USA cars with ford 2.9 engines. Very very rare and will cost lot more. Exclusive car :)
Thank for all helpers and just readers. :)
 

Lou C

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We did have the Ford Scorpio back in the 80s as a Mercury, called the Merkur Xr4ti or some such. It was a cool car but did not sell well. To make the OMC ESA work the way it was deigned, you need an old fashioned breaker point style distributor, with an electronic distributor it may not work at all. There is a company in the USA, called CDI electronics, that makes aftermarket ESA modules that can work with electronic distributors.

​the difference between the Merc system and the OMC system is that the Merc system will momentarily short out the ignition, and if you are too slow shifting it will make the engine stall. The OMC system was somewhat more advanced in that it will lower the idle speed to approx. 450 rpm, to allow the shift to neutral to occur, and as long as the engine can run at that low speed, it will not stall. So in this regard the OMC system was more advanced than the Merc system. But given what you have, if you cannot convert to a points distributor (unlikely) or find a CDI ESA module for an electronic distributor (possible) then wiring it like a Merc may be the only way to make it work.
 

alldodge

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The Red arrow wire goes to the Tachometer
The Pink arrow wire is signal when motor is running to ESA
 

bruceb58

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If you are not running with a points distributor or the distributor that came with the engine, the ESA will NOT work. I would suggest to do what AllDodge said and use the interrupter switch to disable the ignition. Make sure you also wire in the overstroke switch so there is no interruption when your drive is in gear.
 

borman

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Will esa work for me?
Do I have "an old fashioned breaker point style distributor"
 

borman

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Does interrupting (or braking) signal from esa goes to ignition coil? If it is so.... It brakes coil signal!? How does it works? It sends positive signal to negative? Or else?
Does OMC esa system is independent system from engine. Will or must it send interrupting (or braking) signal when just switching gear (or just switch) even if engine is totally taken out? Does esa system needs signal that engine is running?
These are main questions?
I have to figure out what kind of signal from which wire in which moment must come out from esa. How to test esa. When I will understand how, or works it at all, I will figure out what to do next. I understand that merc system is simpler, but it is much harder and expensive for me to just get that system.
Please put someone merc esa system diagram for me to understand how it works.
 

alldodge

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Unable to answer all your questions but you do not have a breaker points distributer, its electronic.
Don't know how it works but you being electronic I would look at momentary interrupt of power to the coil. The OMC switch works the same way as the Merc does (makes and breaks connection), a difference with OMC it also has the overstroke switch.
 

borman

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So I spent some time today with my esa. That wiring diagram is simple. One positive to esa, ground and that is actually all wiring. All other are switches and signal wires. Blue wire is (-) wire (which is activated with switch)....it sends (-) to esa, and esa must send negative (-) signal to coil when switch is activated. But mine esa is not sending that signal. I figured previously written, because the only way to interrupt coil signal is sending (-) to coil (-) . Pulsating like OMC or simple as Merc, it doesn't meter.
The only difference in my wiring and diagram upper, is that I have two free wires. One is gray and other is gray with white stripe. None wire is sending (-) signal.
Maybe someone can tell what to those wires must be connected??? I had them both in one connector (plugin). But I cut it off, because I did not had where to plug it in. As I previously wrote, I had no engine at all.
P.S.
And so...The only thing what comes in my mind is that I have dead esa. ...if only those two wires must have some signals from somewhere!!???
Any ideas or suggestion?!!!
I can make Merc esa system, thats not hard, but cooler would be working OMC esa.
 

borman

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image_252642.jpg
When switching swith, there is (-) signal in red arrow wire.
There is no any signal in blue arrow signal.
And I have one more wire next to red arrows wire (next to gray wire) , and that is gray with white stripe. ???!!!
 

alldodge

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Wish I had more advise but unable. Merc does not use an ESA, all it does is momentarily supplies a ground or 12V to the distributer. The length of time the switch is engaged depends on how much time it takes to go into neutral. The time is done by a lever and spring on the switch plate.
 

borman

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I spoke to one men who works with inboards for a years, and he told that if engine is ok, with normal idling, at about 800 rpm, there is no need for esa. I was arguing, but he was promising.I will see it in spring. For now i had taken off esa, and if I will have need for it, I will make something like Mercruiser. Next info coming in spring..../summer.
 

alldodge

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Look forward to hearing more when things get a bit warmer :thumb:
 

Lou C

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What I might do is call up CDI electronics in Alabama. They make aftermarket OMC style ESA modules and if I recall correctly they do make one that will work with electronic ignition. This is what you'd do if you had an OMC rigged engine and wanted to switch from points to the Delco EST system. I bought one from them that works with the regular points distributor and it works fine. To me the only options are to do that, or wire it like a Merc. I like the OMC ESA system better because it is less likely to stall during shifting as long as your engine is in good enough tune to run at 450 rpm without stalling. I've replaced both the switches and the ESA module but they were 28 years old at the time! So the OMC engineering was really not so bad.
 
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