ESA module confusion

[A1957]

I have a weird problem I'm hoping someone can help me with.
I have a 1988 OMC King Cobra 5.7L. The model number is 574PBRGDP. The ESA module I took off has part # 987571 written on it which is for an engine with a BID (Breakerless Ignition Distributor) made by Pertronix. Problem is my engine has a points style distributor made by Mallory. The distributor is original (I bought the boat new in 1989). The module may have been replaced.
The instruction sheet that came with the new module says NOT to use it with points style ignition. The module that the parts book says to use does not have the same plug connector, in fact it has 2 connectors (my original has 1- 5 wire plug).
The instruction sheet said to check the resistance on the gray/black wire on the engine side of the ESA connector but the connector on my boat only has 4 wires coming out. The engine side pin location for the gray/black wire on the ESA side has a plug in it. Again, factory.
Also, I cannot find a ballast resistor so I’m assuming there is a resistor wire there but I’ve not had a chance to check the resistance.
So my question is has anyone seen this mix of parts? Any wire diagram that shows this combo?
Thanks,

 

[HT32BSX115]

I have a weird problem I'm hoping someone can help me with.
I have a 1988 OMC King Cobra 5.7L. The model number is 574PBRGDP. The ESA module I took off has part # 987571 written on it which is for an engine with a BID (Breakerless Ignition Distributor) made by Pertronix. Problem is my engine has a points style distributor made by Mallory. The distributor is original (I bought the boat new in 1989). The module may have been replaced.
The instruction sheet that came with the new module says NOT to use it with points style ignition. The module that the parts book says to use does not have the same plug connector, in fact it has 2 connectors (my original has 1- 5 wire plug).
The instruction sheet said to check the resistance on the gray/black wire on the engine side of the ESA connector but the connector on my boat only has 4 wires coming out. The engine side pin location for the gray/black wire on the ESA side has a plug in it. Again, factory.
Also, I cannot find a ballast resistor so I’m assuming there is a resistor wire there but I’ve not had a chance to check the resistance.
So my question is has anyone seen this mix of parts? Any wire diagram that shows this combo?
Thanks,

Howdy,

Welcome aboard!

Well you have me a little confused too!

You bought the boat new, but didn't change the distributor or the ESA? How'd the "wrong" ESA get in the boat?

Yours is a 574BPRGDP 1988 (looks like you might have transposed a couple of letters)

Looking at http://epc.brp.com/ Your model came with a points type distributor. There's 2 different distributors though..... one of them is a MALLORY YL670AV. It doesn't give a name for the other one but both appear to be points type. The ESA harness indicates 2 plugs (4-pin, 2-pin) See "WIRE HARNESS, BRACKET & SOLENOID" for your model at http://epc.brp.com/ If one of your plugs is a 5-pin plug, someone changed it, or you're looking at the wrong plug.

The original ESA is 0984276 SHIFT ASSIST (I'm just copy/pasting here) But since it no longer exists, that ESA part number has been superceded more than once....I found Evinrude / Johnson / OMC (0984276) was replaced by 0984730


Another search resulted in a CDI 123-9898-P - Shift Assist Module OMC

Which replaces: 123-9898-4, 123-9898-6,123-9898-8, 982749, 982755, 982774,984036, 984276, 984281, 984730,984740, 985902, 986342, 986837,987738, 987739, 987740.

If you do not have an OEM OMC service manual, you might want to find one that definitely covers your model. Get an OMC manual. (NOT SELOC or Clymer)

CDI electronics has fairly detailed instructions on their site if you haven't looked. If you can't find a ballast resistor, it's either resistor wire or you have a 3-ohm coil (with a 3-ohm coil, ballast is not needed according to CDI)

I hope I have been of some help!

I became intimately familiar with OMC Cobras when I had the 7.5L OMC Cobra in my Four Winns. MAN I'm glad I swapped it all out for the Mercruiser Bravo!

Regards,


Rick

 

[Lou C]

The other points distributor it might have is a Prestolite, that’s what I have in mine. The CDI module Rick mentioned is the is similar to the one I got from CDI when my original failed (after 26 years!) when I also replaced the switches. The CDI module worked perfect with the Cobra shift system. They have a tech line where they will answer questions, give them a call and ask which part number is right for your engine.

 

[A1957]

Sorry about the transposed model numbers. I mentioned that the ESA module may have been replaced in the past. It was in the shop years ago for hard shifting so maybe then. The distributor is definitely original.
The wiring harness is also original and has the single 5 pin connector. The replacement I’m being told I need shows a 4 pin and a 2 pin. The weird thing about mine it the while the ESA module has 5 wires in the connector, the boat side of the 5 pin connector only has 4 wires in it. The whole thing looks original to me.
The failed ESA appears to have a small burn or corrosion mark in the epoxy coated rear. It’s so tiny I can’t tell.
The coil is 1.5 ohms. I didn’t check the wire for resistance but I’ll try today.
The replacement module I got is a CDI 123-7571. That’s where 8 saw on the instruction sheet that’s I’ve got a component mis-match. The 123-9898p or the HD version 123-9800 are what I’m being told I need but are 4/2 pin connectors. I’m going to call CDI again this AM and see what they can tell me.
Does anyone know WHY your not supposed to use the 5 pin ESA without the BID distributor? What’s the failure mode?

 

[HT32BSX115]

Does anyone know WHY your not supposed to use the 5 pin ESA without the BID distributor? What’s the failure mode?

Good question...............The triggering system for most (or all) electronic "points" systems while they emulate breaker type interruption of the coil primary winding they don't do it exactly the "same" way since there's no condenser (capacitor)

Also, if there is no resistor, that might be why the ESA failed in the first place. CDI will probably be able to tell you what is going on with the modified harness since it's probably been done before.

Suffice it to know that you're going to need the right ESA if you want it to work right (or you need to install a pertronix triggering system, which is probably ok too)

Sticking with the points will likely entail replacing the 5 pin plug with a 4 pin plug so it can be easily connected.

Someone up to nearly 30 years ago modified that harness for whatever reason, and they're not talking!

 

[Lou C]

The only thing I can add is that someone may have changed the original ESA to the later style one that uses just the interrupt switch and not the overstroke switch, maybe they did that and modified the wiring. The later style ones used a timer instead of the overstroke switch.
I cant recall the connections because I did the install about 6 years ago but I can say with the standard harness in place the CDI module worked exactly the same as OE. Plug n play. Theirs still uses the overstroke switch so it’s just the same as OE.

 

[A1957]

The wiring is virgin. It’s how it was built. No doubt about it. Here are some pics. I have an interruption switch AND an overstroke switch.
CDI did not return my call today. I’ll try them again tomorrow.
I’m thinking that 30 years ago the 5 wire ESA module was installed but with a points style distributor. As I mentioned before, there is a chance the ESA module was changed in the past because I have had shift issues before but the distributor is stock as delivered from Sanger.

 

[Redrig]

That is wild, certainly looks stock. Even the stringers before the cobras used a 4 and a 2 wire connection .I wonder what the extra spot in the pigtail would be for ?

 

[A1957]

CDI assures me that their part # 123-9800 is what I need. They’re telling me I need to go farther down the original harness and I will eventually see where my 5 pin harness splits into a 2 pin and a 4 pin.
I’ve returned the 123-7571 which is the match for what came off and the 123-9800 should be here next Monday.
I’ll let you know how it works out.....

 

[A1957]

Back from the dead.....So the CDI module number 123-8900 was the cure. The difference was in the wiring on the boat.
On the original module there was a 5 pin connector that only used 4 of the pins. Further down the harness there were 4 and 2 pin plugs and a grounding ring.
on the replacement module, there was no 5 pin connector. All of the wires came out of the back o& the module where it’s potted and went straight to the 4 and 2 pin plugs. It also had a ground ring.
i unplugged the 5-to-4 and 2 section of the harness and went direct. The engine rpm now drops as it should and shifting has been restored!
Thanks to all of you guys that helped with this and I am personally inviting you over to my NEW post in this same forum section where I will be asking about why the drive sounds like a blender chewing ice cubes in slo-mo.