Interesting Ignition Issue.

I just bought my first Jeep and am having a little issue with the ignition. The Jeep is an 81 CJ5 with the 304. The engine fires right away when the starter switch is engaged, but dies immediately when the starter disengages. I ran a jumper wire from the battery to the coil side on the ignition solenoid and the engine runs just fine as long as the jumper wire is in place. I thought this meant the ignition solenoid needed replaced so I replaced this morning only to find that the problem is still there. Would replacing the ignition switch fix this problem? I just don't know why there would only be power to the coil while the starter is engaged.

 

Ballast resistor.

 

Yep

 

This us going to sound really stupid, but what is that and where is it located on my Jeep?

 

Possibly a porcelain block on the firewall.

While cranking, the coil gets full voltage. As soon as you release the key to the 'run' position, the coil is fed through a resistor at reduced voltage. This compensates for voltage drop while the starter is consuming huge amps from the battery.

Just possibly the key switch could have an issue causing your problem, but try bypassing (jumping) the resistor.

 

It's a nichrome wire on that Jeep. Look at the wiring diagram, and it's the connecting wire between the switch and the coil that has a resistance.

The "I" terminal on the solenoid sends power to the coil during starting. Once you release the key, that's no longer connected.

 

Welcome aboard from So.Ga.

 

Well I figured out the ignition issue. The previous owner has the tachometer installed in a way that if its disconnected it breaks the circuit to the coil. With the tachometer installed the jeep runs fine, but it drains the battery if it's not running ‍♂️