TheSamba.com :: View topic

Mon May 02, 2022 3:56 pm

Well, there is no shortage of forum discussions on coils, coil specs and coil replacement options. However I have not seen a comment about the significance of lower than spec resistance on the secondary.

I have one of those 27270 generic, oil filled coils. Resistance between the 1 and 15 terminals is 3.5 ohms ... which I believe is right in the middle of the desired range. However from either 1 or 15 to the center post it is 6,979 ohms. I think the preferred range for this reading is 9,500 - 10,000. The engine starts and seems to run okay. (BTW ... all readings taken with the coil out of the car.) I am wondering where these preferred coil specs come from. There is no mention of them in the Bentley manual that I could find.

Why am I checking the coil? Well, thanks to a senior moment, I left the ignition in the "on" position for a prolonged period of time (30 - 45 minutes) and of course the coil got too hot to touch. Battery was dead after that too. Charged up the battery and the engine started right up and ran, so the points and condenser don't seem to have fallen victim to my mental lapse. Still wondering:

Does the lower resistance at the center post (6,979 ohms) suggest a failing coil?

Is this a concern for a stock ignition system?

Should I expect that the condenser took a beating and plan on replacing it? (I seem to recall reading in another post that leaving the ignition on too long would damage the condenser.)

If any of you think I'll need to replace the coil sooner rather than later, what would you recommend?

Thanks!