Engine replacement wiring mishap

Timothy

Timothy

New Member
Joined
Jan 18, 2018
Messages
9
Location
Vernon, FL, United States
So...I’m not a mechanic but a tinkerer. I replaced the 2.5L engine in my 5spd ‘97 Wrangler with another 2.5 from another jeep.

In the process I didn’t properly label the wires. I ended up connecting the ground from the alternator to the output on the starter. I think I’ve fried a component. The starter would not turn properly but all is right with it now. However, the plugs are not firing now in the new engine. Less than a volt (tested with voltmeter) goes into the distributor cap with the ignition turned to start. The engine turns over fine. No spark on plugs. I will replace the coil in the morning with the one from the original engine. I couldn’t find any blown fuses. Any idea what else or how else to troubleshoot this? The Haynes manual mostly lists Fuel issues but with the plugs out checking for spark I could smell gas in the cylinders.

Any help??
 
The alternator/generator has a ground. I’m looking at the wiring diagram. The starter does too, but I guess it’s internal?? I was talking about the “bottom bolt” as in not the small ignition switch wire or the battery attachment, but the one that sends power from the solenoid to the starter motor. I grounded that and was losing voltage. That’s been corrected but I think I shorted something else out by hooking the alternator ground to the sometimes hot starter motor “bottom bolt” or starter motor terminal.

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There's a good chance you just blew a fuse. But if you already checked that you troubleshoot it as a no spark condition, since you say you can smell gas when cranking.
 
Alternators don't have an obvious ground connection...as in, NO actual wire that comes off the alternator should go to ground. Your alternator should have a connector of some sort for the regulator / rectifier and a large red wire that goes back to the Battery or some other sort of power distribution center. I'm not sure what you're referring to in that diagram that is ground...I don't see it.

Your starter also has NO ground connection that you make through wires. Its grounded internally to the engine block. The starter should have a smaller "signal" wire that closes the solenoid and a larger power wire that spins the motor.
 
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I can do that. G104 may be to ground, but its the circuitry through the reg / rec, nothing that you are going to hook up yourself. Its probably an internal connection to the alternator frame or something.
 
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