OMC: ESA module replaced, still not work

[aJohn79]

I have a 1990 OMC with a 2.3L Ford. RPMs were not going down when manually activating the ESA shift switch. Read many posts here and performed many of the checks suggested. I checked for conductivity and both switches were working ok. Concluded that it may be the ESA module. Purchased Repair's 123-9898-P. Installed it and still the RPMs are not coming down when the switch is manually activated. I still have points/condenser. I purchased the boat used last year. I have replaced plugs, cap, the only I did not replaced was points/condenser since last owner "did" it. I am planing on getting the electronic ignition from Pertronix. However, that won't get installed for couple weekends, and I need to fix the shifting ESA problem before then.
Does anyone have an idea what else can be wrong with the ESA system? does the "P" module works with points and non-Pertronix ignition?
Thanks....

 

[bruceb58]

Re: OMC: ESA module replaced, still not work

Next step would be to determine if the switch contacts are actually ok and that the wiring from the ESA to the coil is correctly connected.

Do you have an OMC service manual with the wiring diagrams...not Clymer or Seloc?

 

[aJohn79]

Re: OMC: ESA module replaced, still not work

I checked for conductivity at the switch plug and I have on/off as the switch is depressed, so, I assume they are working.
It will make sense to check the wiring. The manual I have is the SELOC I think. Why, is it a bad manual? it had helped me a little, they jump many steps and pictures are hard to see.
I also have the wiring diagram on one of the OMC service booklets the previous owner gave me.

 

[bruceb58]

Re: OMC: ESA module replaced, still not work

The Seloc manual covers multiple years. It may be that the wiring diagram that is in that manual may not be the exact wiring that is in your boat. Probably will be ok but just keep that in mind when looking things over

 

[aJohn79]

Re: OMC: ESA module replaced, still not work

if the wrong condenser is installed, will this affect the operation of the engine or ESA? what about the point's gap?

 

[bruceb58]

Re: OMC: ESA module replaced, still not work

You need to check the dwell with a meter. Gap gets you in the ballpark but you really want to measure it with a dwell meter. After you do that, adjust your timing since dwell affects timing

Since you say it running fine but the RPMs are not dropping when you shift or depress the ESA button, you need to address the ESA operation.

 

[aJohn79]

Re: OMC: ESA module replaced, still not work

ok, so I checked all the connections. All work fine. The two switches seem to work. The ESA module engine dual connection, according to the OMC electric schematic, one goes to the coil and the other to the alternator. Both checked ok in the engine. The ground is solid. What else can it be?

 

[Coors]

Re: OMC: ESA module replaced, still not work

The 3 prong finger that they are hooked too; is it moving correctly?

 

[bruceb58]

Re: OMC: ESA module replaced, still not work

What else can it be?

Power to the module.

 

[Boatin Bob]

Re: OMC: ESA module replaced, still not work

Try bypassing the switches all together. Follow the wires from the switches to a 4 pin plug and unplug it. In the end that comes from the ESA (not the switch end) you should see a black wire and a blue wire, there are 2 other blues as well but it's just a jumper. Take a piece of wire or a jumper wire and with the engine running jumper across from the black to the blue, this will simulate the switches, if it works then your problem is in the switches. Other things to check for, corrosion inside the 4 pin plug and the 2 pin plug (purple and gray wires), check for 12v on the purple, the ground wire attached and the gray wire attached to the neg side of the coil.

 

[whywhyzed]

Re: OMC: ESA module replaced, still not work

there's always a chance the new ESA is bad... slim.. I would tend to think your old one still was alive and you will find a wiring problem yet...have a real good look at connector 24 on page A-22 and the other one on A-23 of the Seloc manual. Make sure all the colours are as described. look at that loop of the blue wire at 37.
That 2.3 schematic in the Seloc book looks pretty accurate to me.

 

[aJohn79]

Re: OMC: ESA module replaced, still not work

Thanks guys...

Coors: the 3-prong finger or Y is moving correctly. I tested the ESA by activating the switch manually, though.

Bob: I have not tested simulating the switch with a jumper on the 4-pin connector, can try tomorrow. However, I tested for conductivity on the 4-pin connector and both switches seem to work. The tester goes from zero to infinity as I de/activate the switch.
I tested for voltage on the grey and purple wires (on the 2-pin connector). Connected the other end to the bolt where the ground of the module connects. With the engine not running, and ignition on, I measured 12.3V at each, the blue and gray wires. Are they supposed to supply the same 12.3V?

KJD: checked wiring and looks allright.

Any other ideas???

Will take the GF and her friend boating tomorrow w/o the ESA. Won't be shifting too much.

 

[Boatin Bob]

Re: OMC: ESA module replaced, still not work

I measured 12.3V at each, the blue and gray wires. Are they supposed to supply the same 12.3V?

I'm assuming you meant purple here and not blue? The voltage your seeing on the gray is actually coming through the coil because you have the key on supplying power to the coil. On the 4 pin plug coming from the ESA module does it really have the 4 wires (2 are the blue loop)? Because the newer ones actually only came with 2 since they did away with the overstroke circuit. I can't believe you have 2 modules doing the same thing?

 

[aJohn79]

Re: OMC: ESA module replaced, still not work

you r right, i meant to say "purple" and grey at the 2-pin connector. Those two measure 12.3V.
Regards to the other connector, I have two wires between the 4-pin connector and ESA. The other two wires are jumped as you say two make the two switches work in series. I followed the recomendations in other threads and bought the Repair 123-9898-p. I am planning on adding the Pertronix ignition and coil soon.

 

[aJohn79]

Re: OMC: ESA module replaced, still not work

what happens if I place a jumper between the two wires on the 2-pin connector, the purple and gray (engine side) ? will the engine turn off? will this make sense to try? is there a way to simulate what the ESA is supposed to do?

 

[aJohn79]

Re: OMC: ESA module replaced, still not work

ok... problem fixed.... the 4-pin connector from the new module has very delicate pins, one was slightly bent and was not engaing the "female" connection coming from the switch. Thanks to Bob's suggestion, I jumped the blue and black cable to realize the ESA was working. Then when I looked closer into the pin connector I saw a just slightly bent pin. Bottom line is that my old ESA did not work, which is good. I did not waste my money. Now I am looking forward to installing the Pertronix ignition and coil.
Thanks guys... this board does a great service to the boating community.

 

[Boatin Bob]

Re: OMC: ESA module replaced, still not work

Glad you got it fixed!

what happens if I place a jumper between the two wires on the 2-pin connector, the purple and gray (engine side) ? will the engine turn off? will this make sense to try? is there a way to simulate what the ESA is supposed to do?



Just for your info though, this would not have worked as you would have been feeding 12v to the neg side of the coil. The ESA in a nutshell grounds out the coil to stop it from working but it does it in pulses rather than a solid grounding like Mercruisers do. It only does it long enough for the load to come off the gears in the sterndrive as you are shifting out of gear so it should only last for a second normally.

Anyway you should be good to go with that new Pertronix down the road when you are ready for it.....Happy Boating!