Bigger Alternator?

[Pitbull_SN95]

A quick run through.. built engine and relocated battery to the rear (main positive to starter, starter to fuse box.. Accessories post runs to the alternator.. ground is ran to the engine).

I just bought a new alternator because the last one wasn't charging the battery. I had it tested at 3 different auto parts stores to be sure. I ended up buying the driveworks alternator from Advance Auto Parts. I went out and was driving the car kinda hard before I sell it to make sure everything is working, and not having any issues. I drove it for about 30 minutes, stopped at a stop sign and the car died. I had to push start it to get it running, didn't drive it hard for another 10 minutes home and it was fine. I went to Advance and the alternator was only putting out 12.4V, I had it bench-tested and it was putting out 13.5V. The battery is good, alternator is good.. Any ideas? Do I need to upgrade the #3g wire from the battery to the alternator? or is this not even my problem?

 

[lwarrior1016]

How long has the car been running with the battery in the back? Was it all charging good before the alternator went out?

 

[Pitbull_SN95]

I rarely drive the car, but I've driven it for an hour at the most with no issues right after I relocated the battery. I started to have issues with the alternator and charging system a month ago. I narrowed it down to a bad ground, so I ran a ground from the battery all the way up to the engine. It solved the problem. It seems to be acting up like this when I drive it hard but to answer the simple question, yes it was.

 

[lwarrior1016]

Do you have a chassis ground from the block to the frame?

 

[Pitbull_SN95]

Yes. I had it grounded to the rear frame, but it didn't work out so well. So I ran a new #4 ground from the battery to the A/C compressor bolt, and a ground from there to the passenger side frame. There's a ground on the driver side, to the DS frame.

 

[lwarrior1016]

Well then, all the wiring sounds good to me. Im wondering if the brushes inside the alternator haven't worn a groove in the rotor. My truck did that, not long ago. It would charge intermittently.

 

[evilcw311]

Did you make sure to ground all of the wires that originally went to ground terminal when the battery was up front?!?

If you missed any or if it's not grounded correctly it will cause this.


This message courtesy of crapatalk!

 

[ttocs]

Autoparts stores bech test alts? That is new to me. you ran a ground all the way back up front to the motor? I would try grounding it to the chassis in the back and be sure the frame/block ground is good. Also that new alt didnt' have any kind of special powder coating or anything on it did it? But this is not to say the battery could be bad. take it out, charge it and test the voltage but do not put it back in. Wait a few hours and test the battery again I have seen batteries come off the charger and pass the load test but then when they sit with nothing hooked up they loose voltage and then fail the test.

 

[Pitbull_SN95]

Well then, all the wiring sounds good to me. Im wondering if the brushes inside the alternator haven't worn a groove in the rotor. My truck did that, not long ago. It would charge intermittently.

Well, with it being new (less than 100 miles on it).. I don't think it's that.

Did you make sure to ground all of the wires that originally went to ground terminal when the battery was up front?!?
If you missed any or if it's not grounded correctly it will cause this.
This message courtesy of crapatalk!

Yeah, I double checked those when I did the wire tuck on it.

Autoparts stores bech test alts? That is new to me. you ran a ground all the way back up front to the motor? I would try grounding it to the chassis in the back and be sure the frame/block ground is good. Also that new alt didnt' have any kind of special powder coating or anything on it did it? But this is not to say the battery could be bad. take it out, charge it and test the voltage but do not put it back in. Wait a few hours and test the battery again I have seen batteries come off the charger and pass the load test but then when they sit with nothing hooked up they loose voltage and then fail the test.

Yeah, they set it up on their machine and tested it for me. It passed all 4 tests. I have a ground from the battery, running all the way up to the engine. Then a ground on each side of the end, to each frame rail. It was a standard alternater, no powder coating or paint on it. I even scuffed up the mounting locations so that it had good contact with the block. I will do the voltage test like you're saying.. You don't think it could be the wire from the alternator?

 

[ttocs]

If I had to guess I would say its a ground problem probably from the wire tuck. There are a few different grounds that might have been disconnected

 

[Pitbull_SN95]

If I had to guess I would say its a ground problem probably from the wire tuck. There are a few different grounds that might have been disconnected

I will go over them all since I have a 5 day weekend coming up. I just went and tested the car again. I found a loose power steering bolt, tightened it up and the belt seems fine. It's not slipping now. I tested the battery before start up and it showed 12.3v. I started the car and it went up to 13.4v. I took it for a 15 minute test drive and stopped 3 times to test it, it never went below 12.3v. I'm thinking that the belt slipping off the A/C was maybe not turning the alternator like it should of been?

 

[Pitbull_SN95]

Problem solved. The loose bolt was causing the belt to come off, in turn the alternator wasn't charging up. I bought a new alternator already, so it went on. Thanks guys.