Replacing resistor wire with in-line resistor?

[projo198]

On an OMC 2.3L inboard.

To eliminate the possibility of it being my problem (not always getting spark at the coil), can I replace the resistor wire between my ignition coil and alternator with a heavier gauge wire and install an in-line 9V resistor?

 

[projo198]

Re: Replacing resistor wire with in-line resistor?

This is the one I am considering.

10W8D2 8.2 Ohms Cermet Power Wirewound Resistor : Resistors | RadioShack.com

 

[Grandad]

Re: Replacing resistor wire with in-line resistor?

Electrically, it should make no difference, but I believe resistance wires are/were used rather than resistors because a wire is less likely to fail than an individual component such as a resistor. - Grandad

 

[bruceb58]

Re: Replacing resistor wire with in-line resistor?

That resistor value is way too large. You will drop too much voltage. Look up the spec for your current resistor wire and match it. Should be closer to 1.5 ohm and will need to be at least 30W resistor.

I also have no idea what you mean by a 9V resistor.

If you mean you want to drop 3V so that you have 9V at the coil, you need to measure the resistance of the coil and pick a resistor that is 1/3 the resistance of the coil. That would cause 1/4th of the voltage to be dropped across the resistor.

 

[projo198]

Re: Replacing resistor wire with in-line resistor?

That resistor value is way too large. You will drop too much voltage. Look up the spec for your current resistor wire and match it. Should be closer to 1.5 ohm and will need to be at least 30W resistor.

I also have no idea what you mean by a 9V resistor.

If you mean you want to drop 3V so that you have 9V at the coil, you need to measure the resistance of the coil and pick a resistor that is 1/3 the resistance of the coil. That would cause 1/4th of the voltage to be dropped across the resistor.

Sorry, my electrical knowledge does not match my mechanical knowledge ha ha.

But yes, I want to eliminate the resistor wire altogether and replace it with an external resistor so that my ignition coil gets the required 9 volts from the alternator instead of 12.

I am checking into these, but I believe the automotive application they were meant for only called for 6 volts. I am still searching for the exact specifications.
BWD RU4 - Coil Resistor | O'Reilly Auto Parts

 

[KM7]

Does a Breakerless ignition like the Prestolite BID on my 91 Ford 5.8L 4bbl ever need a resistor wire?

The boat runs great above idle and especially at WOT! I can't get idle below 800 under load (in the water) without stalling.

Looks like a bad coil. The book says the coil is a P/N 3852217 18-5437. Does that coil require a resistor?

Is the function of the resistor to drop the voltage going to the points if there are points? Mine does not have points.

The coil on there now mat not be an original, It is marked Diamond E-035, Japan, 153J0 but that is hard to read.

I hope someone is still reading this thread.