The Stovebolt Site Forums The Shop Area The Electrical Bay Ignition Ballast Resistor ?

What is the correct ohm rating for the brick resistor that will go in the ignition circuit of my 261 six ? Last time I bought one of these for my old International I was surprised to find out that there were different resistence ratings available. I figured they'd be standard and provide a uniform voltage drop on any 12 volt system. So what one is correct for my 261?

Question I have is, whats your primary ohm resistance value on your coil? I believe you want to obtain a 3 ohm drop. This will determine which ballast resistor you purchase that does come in several ohm values.

That's a good question ! It is an old Delco Remy coil that came with the motor that I bought for my current project, there is a number / letter code on it if that would tell us any thing or can the primary resistance be accurately measured with an ohm meter?

you'll find there's only one value available, get an ignition resistor for a 55-59 Chev 12V at your FLAPS or any of the online vendors .... or just get a new 12V coil that's internally resisted [AC Delco U515]

Bill

So if you're sticking with a 6 volt system - that 12V coil will still be okay to use? I guess the internal resister steps it down enough to not burn out the points?

if you're keeping the 6V battery, use a 6V coil, the 6V system doesn't use ignition resistance, internal or external, and I don't know that the internally resisted 12V coil would supply enough power at the high voltage side with 6V, it's designed to reduce the 12V to about 9V so it might not work with 6V at all

Bill

Thanks Bill. My '52 Chevy 3100 is still a 6Volt system - it came with a ceramic ignition ballast/resistor. One wire from the ignition on one tang, one wire from the positive side of the coil on the other tang - and I guess the other wire is a ground to the engine block. Drove around with it for about 2 weeks no problem. A couple of days ago it wouldn't start, the starter wouldn't crank, no spark out of the plug. I was able to replace it with a MSD 9 ohm? ballast resistor and everything worked like a charm until this morning (That was yesterday). The engine wouldn't turn over - the lights were extremely dim. I was able to jump the battery and it cranked right over. Took it home and put in a 6 volt CAR battery from Pep Boys (they had one, Sears had golf cart batteries). I can toss the resistor right? The coil I have is a Delco-Remy, I suspect it's a 6 volt - I don't know though. The car starts very roughly, and the lights are even dimmer. What should I be considering now? Thanks again.

yes, toss the resistor, but I'd check the numbers on the coil to see if it's 6V - there's a bunch of numbers listed here that specify 6V, and later ones do specify 12V - might be worth the few bucks to get a correct new one

sounds like you may have a poor ground, or maybe something grounded that shouldn't be, that's running the battery down - if you don't have a shop manual with wiring diagram, there's one here

Bill

Thanks red58 for confirming that. Still don't know what would "all of a sudden" start running the be battery down. I did check the grounding strap and it's snug - really didn't play with anything else when I replaced the ballast/resistor. I guess it's a start replacing one thing at a time technique?