Ignition coil ID

[slixtyfive]

I haven't had the tractor running in a couple months and it wouldn't start when i tried yesterday - no spark. I'm suspecting the coil but i'm struggling to determine if i need a replacement with the internal resistor or not. This is a mid-70s IH 574 and all references i've found online list both for that model.

The coil itself is a Delco and has RES embossed on the housing - i'm thinking that pry means it has an internal resistor. I haven't found an external res but some of the wiring is 'under the dash' and a pita to get to........

Appreciate the help if anyone knows for sure regarding the embossed RES.

[Toyz]

If it is stamped "res", I would replace with the internal resistor listing. I just got tired of looking at a gas 464 and sent it to the smelter. If i can locate the factory manual which covers both, I will bring it to Slickstock if you don't have one.
Paul

[slixtyfive]

I got to thinking that i should do some checking first - so i actually have voltage on the dist side of the coil. That tells me the coil is OK - right?

[Nathan390]

What do the points and distributor cap look like?

No spark out of coil or at the spark plug?

[slixtyfive]

points and cap appear to be fine

When i said no spark i was referring to no spark a the plug-plug wire and no spark at the cap-coil wire.

I had a brain fart when i was thinking that having voltage a the dist wire off the coil (points wire) meant the coil is OK. For whatever reason i spaced off that the coil needs to have power at the coil-cap wire .....

[slixtyfive]

Well, after replacing just about everything else it appears new points was the trick (even though i had tried cleaning them first with no avail)..

[Toyz]

Glad to hear it! If cleaning/ filing the points didn't show any results and new points "fixed" it, it might be worth the time to carefully inspect the primary wire running to the points. There are myriad of possibilities related to lack of point gap, bad condenser, or poor voltage delivery that will often be corrected by point set replacement. Time spent now checking everything including good grounding of both points and condenser, as well as setting dwell may well translate to less possibility of time spent diagnosing another "no-start"!
Paul