1997 Silverado 5.7 Electric Issue

[Steel]

Hey everyone. I just bought a 1997 Silverado Z71 with 120,000 miles from the original owner. Needs some work as it hasn't ran in about 2 years. (But got it for a great price) and I've been working on it but one issue I have come across is electrical.

I got a new battery. Truck fires right up, while running if I disconnect the battery, truck dies. Alternator right? So I get a new alternator, same issue. Truck fires right up, but if battery is disconnected, it shuts off. Any suggestions?

Thanks in advance!

 

[JohnZ71]

Hey everyone. I just bought a 1997 Silverado Z71 with 120,000 miles from the original owner. Needs some work as it hasn't ran in about 2 years. (But got it for a great price) and I've been working on it but one issue I have come across is electrical.

I got a new battery. Truck fires right up, while running if I disconnect the battery, truck dies. Alternator right? So I get a new alternator, same issue. Truck fires right up, but if battery is disconnected, it shuts off. Any suggestions?

Thanks in advance!

The wiring connector to the alternator is installed securely? Are the cable connections clean?

My Tahoe has a fuse mounted on the fan shroud that connects the alternator to the battery, try checking that.

Do you have a test light or multimeter?

 

[Steel]

The wiring connector to the alternator is installed securely? Are the cable connections clean?

My Tahoe has a fuse mounted on the fan shroud that connects the alternator to the battery, try checking that.

Do you have a test light or multimeter?

I will check that out tomorrow. Thanks!

Yes I do have a multimeter.

 

[JohnZ71]

Check voltage on the harness going to the alternator, check continuity of the fuse, and it wouldn’t hurt to ohm out the cable connections. If you’re still using the factory side screw terminals, they’re notorious for corroding. A long time ago my alternator was not charging for that reason. I cleaned all the connections and it went right to work.

 

[jd33173]

Hey everyone. I just bought a 1997 Silverado Z71 with 120,000 miles from the original owner. Needs some work as it hasn't ran in about 2 years. (But got it for a great price) and I've been working on it but one issue I have come across is electrical.

I got a new battery. Truck fires right up, while running if I disconnect the battery, truck dies. Alternator right? So I get a new alternator, same issue. Truck fires right up, but if battery is disconnected, it shuts off. Any suggestions?

Thanks in advance!

Dont do that, put your meter on the battery, if you are pulling 14.something w ac off or 13.something w ac on you are good. Dont pull the battery terminal, great way to fry some stuff.

 

[Schurkey]

I got a new battery. Truck fires right up, while running if I disconnect the battery, truck dies.

STOP disconnecting the battery. You can kill the alternator by disconnecting the battery with the engine running.

Are there any other problems besides the one you created?