Thread: Alternator Intermitent Issue

So I was having my car tuned a couple of weeks ago and was unable to finish because the voltage reading at the injectors was fluctuating between 11.8V and 13.5V. When I disconnected the positive from the battery the car died, however I've used the car for longish drives and the battery has never died. I thought that the alternator was bad so I replaced it, even with the new alternator when I disconnect the battery positive the car dies.

My alternator is rear mounted and the battery is in the trunk, I'm using a ka24 alternator and the pulley that it has is from a FWD sr20 alternator.

I read about using a MX6 pulley on rear mounted alternator. I saw in Mikos thread that the pulley on the alternator does look smaller than the normal one. He is not keen on sharing info so I'm not gonna ask him.

Check your alternator harness to make sure its not melted , also check your ground.

Thanks, I'll recheck it tomorrow.

The ground does look kinda sketchy, I'm going to build a new one. I was thinking about making two ground cables for it, one connected to the chassis and the other connected to the block. Any reason not to do this?

It wasn't the ground, the word thing is that it doesn't always shut down when I disconnect the battery terminal.

So at 1k RPM it's putting out 14V, anything under 750ish RPM and the car shuts down if I disconnect the battery. So it definitely should be the pulley, I'm switching it to a smaller one I found.