very annoying alternator problem!

[MRMATRIX69]

Well guys here's the issue. I have replaced my alternator with a 200 amp unit. I have upgraded my power out from the alternator to 4 gauge straight to the battery. The problem is when I rev over about 3000 it blows the alternator fuse in the engine compartment fuse box. Now I have checked for shorts and shorts to ground and found nothing. I checked that there is battery power at the alternator wire in the connector that is on that fuse. All seems fine until I rev it and then it pops the fuse. I have had the alternator checked out because it was a rebuild(long story) and they say it is all good. I am leaning towards the regulator but i figured i'd give you sterling guys a shot at it first.

 

[HISSIN50]

Did you remove the stock charging cable at the power distribution block? Are there any other wires associated with that wiring?
I have not ripped into mine (I will upgrade the wiring at some point on the 94), but on a fox, one has to retain the stock charging cable's connection at the battery/solenoid, since there is one wire packaged with those wires, which controls voltage regulation.

Otherwise, you could have the alternator bench tested.

Good luck.

 

[urban96]

sounds like a bad voltage regulator

just out of curiousity tho, do your plug wires go any where near the back of the alt?

 

[94-302-vert]

I almsot say bad battery...

It seems that the alternator will need the higher engine RPM to generate enough current to blow that fuse... almost as if the battery is contastnly trying to be charged???

Do you have a multimeter that you can use to monitor the voltage of the system at the battery during all of this?

 

[MRMATRIX69]

I have a reasonably new battery. I have checked the wiring and the plug wires are about 6 inches away from the alternator. I had a multimeter while checking all this and it shows charging fine until it pops fuse. I have kept the stock charging wire to the distribution block and added a 4 gauge straight to the battery. Thanks again.

 

[94-302-vert]

So the battery was at like 12 (or 11.8) volts when sitting, went down to 10 or so volts during cranking the engine, then jumped to between 13.8 and 14.4 and just stayed there until blew?

 

[MysteryMachine]

I got a 200 AMP and was having charging issues. I took it to Napa they tested it said it was fine put in a new battery same problem. Got a hold of the guy i bought it off of said send it back. Sent it back he tore it apart found a wire had come loose inside. Fixed it up works great now. Might not be your problem but its just a thought

 

[MRMATRIX69]

Battery voltage was mid 12's sitting still. Running it's at 14.4-14.5 until it pops the fuse.

Update: I talked to Carquest were the alternator was rebuilt and it's getting sent back to them to get checked again, so yea I'm out of my car for another 3-4 days.

:damnit: