[von239]

i have a 1991 bonneville 3.8 and the wiring harness sshows resistance in all the wires, but when its plugged up no fire is coming from the coil.What causes this.

[sedan delivery]

HERE ARE SOME POINTERS. HOPE IT HELPS
COIL TEST
Remove the ignition coil(s).

Using an ohmmeter, check the resistance between the primary terminals on the underside of the coil. The resistance should be 0.50-0.90 ohms.

Check the resistance between the secondary terminals. It should be 5,000-8,000 ohms.

If the coil failed either test, replace the coil.

THIS LINK WILL TEST THE MODULE
http://www.autozone.com/autozone/rep...96b43f8038fb5b

THIS LINK IS FOR THE CRANK SENSOR TEST
http://www.autozone.com/autozone/rep...96b43f8038fb48


THIS LINK IS FOR THE CAM SHAFT SENSOR TEST
http://www.autozone.com/autozone/rep...96b43f8038fb56

[LATECH]

Originally Posted by von239

i have a 1991 bonneville 3.8 and the wiring harness sshows resistance in all the wires, but when its plugged up no fire is coming from the coil.What causes this.

I would say most likely the crank sensor went out. The module can fail but there is 3 seperate curcuits to run the coils , it isnt as likely the module failed , but it could , more likely the crank sensor went out. The same with the coil, all 3 coils wouldnt go bad all at once,most of the time one coil goes bad( there are 3 seperate coils in the coil pack) and you will have a miss on one or two cylinders.

The crank sensor is the heartbeat of the system , without it, nobody goes to work. If your gonna throw a part at it , I would start there.
Or if you have a Oscilliscope you can check it all out.
This site may give you what you need, and I wont have to type so much

http://easyautodiagnostics.com/gm_ig...n_module_1.php
Its a little lengthy but it is good info.