1988 OMC Ballist resistor location??

[rboyer224]

Hello. Does anybody know the location of the ballist/primary resistor on a 1988 Four Winns Liberator with the 350 OMC king cobra? It talks about it in all the books but I can't find it in either the wiring diagrams or on the boat. Is it under the dash panel or in the engine compartment? I would greatly appreciate your help. Thanks.

 

[Don S]

Re: 1988 OMC Ballist resistor location??

On the engine, near the coil.

 

[rboyer224]

Re: 1988 OMC Ballist resistor location??

Okay thanks, do you know what it looks like? Will it be noticable or does it look more like a fusable link? Thanks again.

 

[Boatin Bob]

Re: 1988 OMC Ballist resistor location??

See pic below, You will have a resistor wire, look for the red/purple wire coming off the positive post of the coil, it goes back into a splice that comes off the alternator.

 

[rboyer224]

Re: 1988 OMC Ballist resistor location??

A fusable link usually just looks like an inline fuse or a fat spot in a wire. Thanks for your help. I'll look for it tomorrow.

 

[HT32BSX115]

Re: 1988 OMC Ballist resistor location??

Oh man...not another Liberator!

This proves that they must have made more than 1!!


My 87 service manual may not be right for yours but there's a discussion that indicates that "Resistor Wire" is used in the ignition circuit.

The following was excerpted from my OMC Service Manual #507605

Resistor Wire

For Models: All

Special Tools Required: Ohmmeter

Test Procedure - Resistor Wire

Disconnect 20 gauge purple/red resistor wire from ignition coil positive (+) terminal. Disconnect purple lead at back of alternator. Connect ohmmeter between purple/red wire at coil and purple wire at alternator. Meter low ohms scale should read:

Resistance in Ohms............................ 2.0 plus/minus 0.5

If resistor wire fails test, do not shorten wire. Replace engine wiring harness.

I am thinking you really do not want to replace the harness. You could simply use a ballast resistor in place of the wire or get yourself some resistor wire of the correct resistance to replace it if it's open.


Regards,



Rick

 

[rboyer224]

Re: 1988 OMC Ballist resistor location??

Excellent. Thanks guys. That would also explain how the ESA gets less than 12V. I wonder why they call that a splice on the diagram and not a resistor? Anyway, thanks again. Hey Rick, how envolved is the swap from an OMC outdrive to the Bravo III? I've been thinking of doing that when this drive wears out.

 

[Boatin Bob]

Re: 1988 OMC Ballist resistor location??

You are not reading the wiring diagram correctly, the ESA does not get less than 12v only the coil does because the purple/red is a resistor wire, the splice is not the resistor either, it is simply a splice(connection).

 

[HT32BSX115]

Re: 1988 OMC Ballist resistor location??

Excellent. Thanks guys. That would also explain how the ESA gets less than 12V. I wonder why they call that a splice on the diagram and not a resistor? Anyway, thanks again. Hey Rick, how envolved is the swap from an OMC outdrive to the Bravo III? I've been thinking of doing that when this drive wears out.

Hi Robert,


I donno about wearing out a Cobra....mine is 20 years old and it's not worn out yet!
Taken care of they last as long as any of them!



It's actually pretty easy. you just pull everything OMC and bolt in everything Merc.... You do have to drill 2 additional holes (Cobra has 6 studs, Bravo has 8) The rest of the cutout is the same.

You may have to relocate the front engine mounts forward or back. I did a bunch of re-fiberglass in the engine compartment because Four Winns sdid a pretty poor job in there.... You can even use the OMC wiring harness (plug is the same) although there's an extra wire for the alarm. Control and cables need to change. I used a Teleflex CH1700

 

[rboyer224]

Re: 1988 OMC Ballist resistor location??

Hey Bob, I don't know about you, but it looks to me like the purple/red wire you talk about it connected to the purple that goes to the ESA. That would mean they both get the same supply correct??

 

[HT32BSX115]

Re: 1988 OMC Ballist resistor location??

That is a splice. direct connection. there should be a voltage drop across the "resistor" wire only.

 

[Boatin Bob]

Re: 1988 OMC Ballist resistor location??

I don't how to put it any simpler but the red/purple wire coming out of the splice is the resistor wire and it only feeds the coil not the ESA. Maybe in your mind remove the red/purple wire and place an actual ballast resistor in there.

 

[rboyer224]

Re: 1988 OMC Ballist resistor location??

Yes, that makes sense. I just wonder why people say not to remove that resistor wire when going to an upgraded/HEI/MSD ignition? I've read a lot of forums that say the ESA will not work if you remove the resistor wire and run 12V to the coil. Why would that be if the ESA is operating on 12V? It would seam that removing that wire and getting the full advantage of 12V to the new coil would be a huge advantage.

 

[HT32BSX115]

Re: 1988 OMC Ballist resistor location??

It shouldn't matter.

If you look at the circuit diagram, you'll see that the A+ (thru the ballast "resistor") goes directly to the "plus" side of the coil.

The ESA (output) is essentially in parallel with the points/condenser.

The ESA using an electronic switching transistor and associated electronics "shorts" out the points/condenser circuit to briefly stop ignition (it actually "pulses" it) to cause momentary torque "pulses" to allow you to easily pull it out of gear.

The gray wire that goes from the ESA to the NEG coil lead & dist also goes directly to the tach.

(by the way, the instrument cable diagram in my OMC manual shows the tach wired wrong....they have the gray, dark blue, black and purple wires all connected to the same "lug" on the tach! An obvious huge error that would blow fuses and/or cause fireworks!!!

All this works great with mechanical points. If you use an electronic ignition like Pertronix or some other electronic ignition like MSD etc, you must have some sort of isolation to prevent ESD/electronic ignition system interaction. Pertronix does it with a diode/resistor combination. I'm sure MSD does a similar circuit.

If you install an MSD, Pertronix or similar system just follow their directions with the "ballast" wire. Some may tell you to remove it and others may just have designed theirs to keep it in place.

 

[rboyer224]

Re: 1988 OMC Ballist resistor location??

Yes, I've finally figured it all out, with your help of course. Thanks. MSD does have a plug in shift assist module that interrupts their coil. Thanks agin for all your help, and Boatin Bob,....that's an awesome color wiring diagram. Do you have the other half of that one? The one that has the dash and gauges on it? If so, could you post that one too? I made a nice color copy of the other one. My diagram is b/w. Thanks.

 

[rboyer224]

Re: 1988 OMC Ballist resistor location??

See pic below, You will have a resistor wire, look for the red/purple wire coming off the positive post of the coil, it goes back into a splice that comes off the alternator.

Hey Bob, do you have the other half of this color wiring diagram? If so, that would be great. Mine is black and white. Thanks.

 

[bzuchero]

Re: 1988 OMC Ballist resistor location??

What wire needs to be cut to add the resistor? Purple and red?