How to test an ESA module without an engine ?

[HorizonblueDK]

I have an ESA module for a 4.3 V6 OMC Cobra that I would like to sell. I'm not going to use it ever, I think.

I would like to test it, so I can prove for an interesting buyer that it works. But I don't have an engine I can put it on. Well I have a V6 engine in the Draco 1800, but that one has electronic ignition.

Has anyone tried to connect it to a battery with a few wires, a light bulb and so on, so you could perform a test on the work bench?

 

[HT32BSX115]

Re: How to test an ESA module without an engine ?

I have an ESA module for a 4.3 V6 OMC Cobra that I would like to sell. I'm not going to use it ever, I think.

I would like to test it, so I can prove for an interesting buyer that it works. But I don't have an engine I can put it on. Well I have a V6 engine in the Draco 1800, but that one has electronic ignition.

Has anyone tried to connect it to a battery with a few wires, a light bulb and so on, so you could perform a test on the work bench?

Howdy,


I seem to remember a procedure to test an ESA when connected to the engine. You could look at the manual for the procedure.

Have a look at Boatinfo - OMC 1986-1998 Service Manual

Go to page 10-62 (OMC stern drives) Fig 52 and/or 153.

You'll be looking at the engine wiring diagrams for the GM and Ford engines. The ESA is wired with a "control" wire connected to the negative lead on the coil (where the points are connected) The ESA is in parallel with the points. This would allow the ESA to "short" the points to ground intermittently.....(there must be an "open collector" to do the "shorting!)


You could also just connect it to any engine and see if it "stumbles" the engine.

From the wiring diagram, There's appears to be only 4 connections to the ESA............ there's an A+ and Ground (-) connection, and one switch connection.

There's 2 switches for normal operation. An actuator switch and an over-stroke switch............. but they're connected to the same BL (blue) wire.

The GR (Gray) wire goes to the (-) points side of the coil.

The PU (purple) wire is A+ (12v DC)

The B (black) wire is ground.

The BL (Blue) wire is switched to ground THROUGH the actuator /over-stroke switch.

It appears the ESA intermittently grounds the (-) the GR wire, so you may not be able to see the rapid "pulses" on an analog meter (if they're too rapid) .

Since the ESA appears to "pulse" the ignition, (causing the engine to "lope") you could probably wire it using a "breadboard" hookup and an oscilloscope.

Connect 12v through a 1K resistor to the gray wire (the one that would go to the (-) coil connection).

Connect another 1k from the gray wire to ground. (This will create a simple voltage divider with 6v across each resistor)

Connect the Oscilloscope across to second resistor (the one that goes to ground)

Power up the ESA and actuate the switch connected to Blue wire.

You should see voltage across the resistor (the one connected from the gray wire to ground) until you actuate the switch.

Depending on the pulse rate, it could either show no drop in voltage or a slight drop (measured with an analog meter)

If it's a rapid pulse, it'll be very clear on a scope.

It's also possible that the ESA provides pulsed 12v DC to the negative side of the coil. If this is the case, you would see it on an analog meter or a scope. and it might even light a small bulb!



To make it easier though, my suggestion would be to just wire it up to an engine and try it!


I'll assume you're not trying to sell it here. (classified ads are prohibited)

You could put it on EBAY or craigslist though. Don't expect to get more than about $25 or so. (new ones are around $100)



Cheers,


Rick



Ok,


Here's a thread where someone did simple test procedure.....essentially what I'm suggesting above...... iBoats search is your little friend!

http://forums.iboats.com/omc-i-o-inboard-engines-outdrives/esa-not-working-501191.html

 

[HorizonblueDK]

Re: How to test an ESA module without an engine ?

Thanks, Rick.

I'm not trying to sell it here. I will sell it locally(no shipping), so people can come and see that it works, before purchase.

It's not going to cost much, but I think it's a waste to throw it out, if it works.

I was hoping that the ESA module could light a small bulp, since I don't have an oscilloscope. Think I will give that a try, maybe with an LED lamp.

I believe that it should be possible to see a flashing light from a bulp, since the pulses emitted from the ESA isn't that fast I guess.

A friend has a V8 Cobra, with electronic ignition, where the ESA module has been ditched. We have tested to see how fast it is necessary to interrupt the ignition to make the engine stumble. Quite easy, just put your finger to the interrupt switch and start pulsing. Approx 3 times per second was adequate, to make the V8 stumble. The faster the pulses, the less stumble.

 

[HT32BSX115]

Re: How to test an ESA module without an engine ?

Thanks, Rick.

I was hoping that the ESA module could light a small bulp, since I don't have an oscilloscope. Think I will give that a try, maybe with an LED lamp.

I believe that it should be possible to see a flashing light from a bulp, since the pulses emitted from the ESA isn't that fast I guess.

Yeah. You'll have to experiment. It either pulses 12v to the negative side of the coil or it grounds it.

I never played with mine but it should be easy to test. If it produces a voltage, that'll be easy to measure with a multi-meter.

If it's an open collector ( & goes to ground while pulsing), then you could probably also use the resistor technique with an LED.

Instead of 2 resistors, use 1 in series with an LED to ground. put 12v on the resistor and put the output of the ESA to the LED.

When it goes to ground it'll kill the LED ........


12vdc

GND


Current limiting Resistor calculator for leds

Using 12v and most red or green leds, the above circuit would use an approx 500 ohm, 1/4w or higher resistor.

Connect the gray wire where the word "current" is. The LED will flash at the "pulse" rate if the thing works.

 

[boobie]

Re: How to test an ESA module without an engine ?

Very simple test. If someone needs one, let him try it on his motor and if it works, it's okay.