Ignition coil check on my 76 (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Mar 18, 2021
Threads
4
Messages
25
Location
Temecula CA
Hi everyone! Here are my ohm readings from the ignition coil. Is it ok or replace?
Primary 3.1
Secondary 9.93

Its original...
20200808_120526.jpg
 
Hi everyone! Here are my ohm readings from the ignition coil. Is it ok or replace?
Primary 3.1
Secondary 9.93

Its original...View attachment 2632214

Per the factory service manual, the late coil (used with an igniter) primary coil resistance should be 0.5 - 0.7 Ohms, and the secondary coil resistance should be 11.5 - 15.5 kOhms.

Are you sure you were reading the right band on your ohmmeter?
 
coil test.png
 
Per the factory service manual, the late coil (used with an igniter) primary coil resistance should be 0.5 - 0.7 Ohms, and the secondary coil resistance should be 11.5 - 15.5 kOhms.

Are you sure you were reading the right band on your ohmmeter?
Oh I'm sure I'm doing it wrong. 😆 I just rechecked and took some
20210331_195623.jpg
20210331_195729.jpg
pictures with my settings.
 
Oh I'm sure I'm doing it wrong. 😆 I just rechecked and took some View attachment 2632369View attachment 2632370pictures with my settings.

Well, your secondary resistance is 10,180 Ohms, so much closer to spec but not quite there. Your primary resistance is still an order of magnitude more than spec, unless I'm not reading the scale on your meter correctly.

The ignition coils that I've seen go bad, usually cracked/broke some of the wire windings due to vibration. Usually when that happens, the resistance numbers are way off, especially in the secondary circuit. So I'm not sure what to think about yours. Has your truck been running with this coil? Did you have any symptoms that made you suspect a bad coil? Bottom line: that one is out of spec, and a new one should not be expensive, so if it was mine I would replace it.
 
Thanks for the replies. I recently rebuilt the engine and carb. I have the truck running decent(starts and runs good, no loud backfires, chugging). She's runs alittle rich with an occasional pop out the tail pipe and notice the timing bb jumps around at times. I'm sure carb needs better tuning. I only checked the coil mainly because I was curious on its readings.
 

Users who are viewing this thread

Back
Top Bottom