Continuous alternator failure??

[74Chev]

This problem started when I upgraded to a higher output alternator. I am using Bosch #Al559x which is 105amp. output. I believe it is stock for a mid 80's Cavalier or Corsica. The first one lasted about 1 week, then voltage dropped to 12v. The second has only about 50mi. on it and when I started it up tonight after sitting about 1 week it is back to 12v. I checked for power at all the important connections and it is good. I don't have a multi-meter so I cannot check voltage at different points. I have to rely on my auto meter guage. I have dual yellow top batteries wired into a marine type switch. The alternator output wire is 8ga. running directly to the starter wire post on the switch. I have the sensing wire hooked to the junction block on the firewall. It seems that the requlator is not engaging. Why are these alternators failing? I have very good wiring and good connections but something is obviously wrong. This is getting ridiculous. Any ideas appreciated.

 

[jhrody]

I went through 4 100amp alternators on a '74 Nova I had, all within a few thousand miles. Eventually I found a bad negative connection to the battery. Ran a new cable and another connection to the body and the alternator problems went away.

 

[gumneck]

I have a 1969 C-50 with 366 cu. and I thought I had a bad alternator. Replaced it and the new one did the same thing. Killing my battery. Replaced the plastic connection piece that plugs into back of alternator and walla. I mistakenly assumed the first alternator was bad cause it was old and I'm also a parts replacer as a opposed to a real mechanic.

tom

 

[87sm465np208]

REally, so you can put that ol alternator in a truck and it will work, hmmmmm how much was that alternator and how does one aquire one of them? /forums/images/graemlins/thumb.gif

/forums/images/graemlins/usaflag.gif /forums/images/graemlins/truck.gif

 

[TX Mudder]

I had a lot of problems getting my alternator to work right. I ended up picking up a 100 amp 1 wire alternator for $89 fromt JEGS. Haven't have a single problem since - really like it!
-- Mike

 

[NITRO]

u can pick up a reman alt at autozone for $22. then just have it modified for more amps. its been working for me.

NITRO