Ignition coil test

[Mnoverboard]

Hello all, I think my coil died and am looking for best way to test. Can't seem to find info in the manual. Hooked up in line tester to spark plug - no spark. I'd like to know how to troubleshoot a coil problem vs ignition module problem. 4.3 GL PEFS. Thanks in advance, cheers, Patrick

 

[gm280]

Mnoverboard, exactly how did you test the coil? If you own a meter (DVM Digital Volt Meter) and know how to use it, you can set the meter to the ohms scale (resistance scale) and read the primary side of the coil. It should read a pretty low reading but not zero. Then do the same to the secondary side and you should read a lot higher value, but again not zero or opened. If either side reads shorted or opened, you need a new coil. Of course all these readings are with the coil not connected to anything else. JMHO!

 

[Mnoverboard]

I haven't tested the coil as of yet.. that's what I'm trying to figure out. The only thing tested is that I have no spark at the plugs, and I have 12v coming into the coil.Purple wire.

 

[bruceb58]

Tests are in the service manual. Should measure .35-.45 ohms between the purple wire terminal and grey wire terminal. Likewise between purple and high tension.

Should also measure open between the purple and frame of the coil.

This is assuming you have the Delco EST distributor.

 

[Mnoverboard]

Thanks for info, will test tomorrow. In line tester between coil and distributor tests good. Checked continuity of harness from coil to ignition module- good. Current not leaving distributor to plugs so leaning towards ignition module. New rotor, cap, plugs, and wires 2 yrs ago.