I installed a Sierra Marine Delco EST Conversion Kits 18-5514 on a 1985 OMC(GM) 5.7 Litre that had a Prestolite Points ignition. The system has a shift interrupt setup that used a momentary grounding switch to decrease RPM's when shifting. The new setup requires changing the shift interrupt switch from momentary grounding to a MOMENTARY BATTERY VOLTAGE SUPPLY SWITCH. I am confused by the instructions regarding the procedure to complete this step and hope someone on here can give me specific instructions so I may use the new setup correctly. The instructions say to "Determine proper routing of shift interrupt harness and wire to shift interrupt switch. Use 18 AWG purple wire and route from key on 12VDC circuit to shift interrupt switch." I am really hoping someone can elaborate on those instructions with a much more detailed explanation of what exactly needs to be done. Do I need a different switch? IF so, which one? What existing wires will be used and how will they need to be connected? What new wires will be needed and exactly how are they to be connected to prevent shorting out the new module, etc? I am fairly mechanically inclined and do not want to damage the new distributor and related parts.
This is one solution I saw online and would like to know if it is correct and any other details that are missing or incorrect. "How to Reconfigure the Wiring
This is another solution I saw online: "
To change your OMC shift interrupt from a momentary grounding switch to a momentary battery voltage (B+) setup, you must reconfigure the micro-switch wiring and utilize a 12V relay. Attempting to send live 12V directly through the stock micro-switch and into your Electronic Shift Assist (ESA) module will damage your electronics. [1, 2]
The 3-Step Conversion Process
1. Isolate the Micro-Switch
Disconnect the two wires leading from the shift interrupt micro-switch on your engine shift bracket. These are typically part of a 3-wire or 4-wire connector block assembly. [1]
2. Wire the Switch to a Relay (The Trigger)
You need to convert the switch into a trigger for a standard automotive 12V relay (e.g., Bosch-style).
This is one solution I saw online and would like to know if it is correct and any other details that are missing or incorrect. "How to Reconfigure the Wiring
- Locate the 12V Power Wire: Identify the ignition-switched power wire (typically purple or pink) that runs from your ignition switch to the BAT terminal on the HEI distributor cap. [1, 2, 3]
- Cut and Reroute: Disconnect this 12V wire. Route it to one terminal on your shift interrupt switch. [1]
This is another solution I saw online: "
To change your OMC shift interrupt from a momentary grounding switch to a momentary battery voltage (B+) setup, you must reconfigure the micro-switch wiring and utilize a 12V relay. Attempting to send live 12V directly through the stock micro-switch and into your Electronic Shift Assist (ESA) module will damage your electronics. [1, 2]
The 3-Step Conversion Process
1. Isolate the Micro-Switch
Disconnect the two wires leading from the shift interrupt micro-switch on your engine shift bracket. These are typically part of a 3-wire or 4-wire connector block assembly. [1]
2. Wire the Switch to a Relay (The Trigger)
You need to convert the switch into a trigger for a standard automotive 12V relay (e.g., Bosch-style).
- Run a switched 12V source (purple wire from your ignition, or the B+ terminal) to Terminal 85 on the relay.
- Connect one wire of your shift interrupt micro-switch to Terminal 86 on the relay.
- Connect the other wire of the micro-switch to a reliable engine ground.
- Result: When the switch clicks momentarily during shifting, it completes the ground circuit and activates the relay. [1, 2, 3]
Now wire the load side of the relay to temporarily cut the ignition just like the factory setup intended. [1]- Run a constant 12V power source to Terminal 30.
- Connect your distributor or ignition coil negative kill wire to Terminal 87a (the Normally Closed terminal).
- Result: When the relay is un-energized (normal boating), power flows straight through. When the switch clicks, the relay energizes, opening the circuit at 87a to momentarily cut the ignition. [1, 2]
If you are performing this modification because you installed a newer ignition setup (such as a Thunderbolt ignition or a conversion kit), always test the voltage to ensure your ESA module can handle the load"- THOUGHTS?????
I did search the forums and was not successful in identifying this exact operation.
THANK YOU FOR ANY HALP