OMC ESA pertronix fix. Help I need this workin before tomorrow!!!

[marlinempress]

ok I installed the pertronix ignition conversion for a prestolite dist. in my omc 800 stringer '85. It's a 5.7L. I made the diode fix to make it compatible with the ESA, but I'm not sure how to hook up the three wires from the circuit. This is the diagram for the fix: http://www.pertronix.com/tech_suppor...s/diodefix.pdf . On my ign. coil neg. post as it is now before doing anything to it, I've got two of the same colored wires going into one ring terminal (I don't remember the color) and the black wire from the ignitor unit. I'm not able to follow this diagram...It sounds as if there's only supposed to be one wire from the ignitor and one wire from the ESA....But I've got a total of 3 wires, two that go into a run wrapped in tape so I can't trace 'em that're the same color. Has anybody done this diode fix on an omc 800 successfully? Thanks for any info!Matt

[Don S]

I know I can't help you, cause I didn't even know the stringers had the ESA system. I thought that was strictly Cobra

[marlinempress]

hm well...thanks for the reply anyway!

[marlinempress]

oh c'mon!!! anybody!?!!?

[Boatin Bob]

Ok...are those 2 wires gray? What OMC did was take the gray wire (output from ESA) and the other gray (tach wire) and put them together. I would cut them off at the ring terminal. Use an ohmmeter and then disconnect the 2 wire connector at the ESA (should have a purple and gray wire) then find out which one of these gray wires is at the coil end because thats the one you want to hook up to the Pertronix diode fix. Put a new ring terminal on the other gray and reattach to the coil because that should be your tach wire. Hope this makes sense and helps you.

[marlinempress]

sweet!!! I'll give'er a try right now! That helps a lot thanks!

[marlinempress]

hmm...it still didn't work...I wonder if I fried the diodes while I was soldering it. It would seem to me there should be no continuity one way and a ton o' continuity the other way. But as of now I'm getting like 900k of resistance one way like 1.3Mega the other way....that just doesn't sound right.

[Boatin Bob]

No it doesn't but you may want to unsolder them and check again, depends where you are attaching the meter. Were you able to find your ESA/Tach wires at the negative side of the coil?

[marlinempress]

Yep I was able to locate the two wires and isolate the ESA wire from the tach. Thanks a bunch for that info. When I hook up an ohmmeter to the diodes in the circuit, doesn't it just send a small current between the two probes? Is it possible to fry those if you get 'em too hot while you're soldering. If I remember right the diodes should be able to be tested while in a two-ended open circuit, current has to be disconnected and broken to test it. Maybe I just remember wrong though. I have them wired in series with the band on the far side of the diodes (furthest away from the neg. coil part of the circuit). Yet the small discrepancy in continuity that I have seems to be opposite per diode...??

[Boatin Bob]

Are you able to get the meter probe in between the diodes? I don't think I've ever measured end to end with 2 diodes in series so not sure what to expect for results. If not too much trouble I would unsolder them and measure them separately to be sure. I have seen many posts where guys have built that fix and it worked very well so unless your diodes are toast I don't see any other reason (assuming your ESA was working prior to this)

[marlinempress]

Yeah I'm able to get the meter probe between the diodes. I'm thinking maybe I'm not getting a good reading because I'm not passing the breakover voltage of this particular diode. Any ideas on that? Also..if I remember right the ESA worked only intermittently beforehand. Is there anyway to test the ESA? I checked the overstroke and stumble switches and they're fine. Another thing, I only have like 18 gauge wire for the leads on the diode fix. Should they be bigger than that? or is there never much current going through them?

[Boatin Bob]

Not sure about the diode voltage, is your meter using a AA or 9v battery? Any chance you can get another diode (the same) for testing by itself? The only way I know how to test an ESA is actually in a boat running by tripping the interrupt switch in idle and see if the engine stumbles. I would think 18 ga is OK, pretty the ESA wires can't be much more than that maybe 16 ga. Last resort would be to call the support guys at Pertronix, I've heard they're pretty good at helping diagnosing these problems.

[newport dave]

Seems like with an ESA that only works sometimes, and an ESA fix that doesn't work, the best solution would be to get a new Pertronix compatable ESA module. http://rapair.com/Default.aspx?tabid=61 enter part number 123-9898Dave