Archived Alternator Dead: Huge Current Drain

[MacGreenie]

Working under the hood today I happened to touch the back of the alternator with a wrench for just an instant... . got a bit of a spark.



Now the alternator will not put out any power.



Batteries are 12 volts static by themselves... but go down to 10 volts when you start... . and they stay at 10 volts.



I have a shunt at the PDC that reads power output from the alternator and all I get is a current drain with the motor running.



I checked the alternator input at the PDC with the motor running and got 34. 5 volts! The battery side of the PDC (next wire over) read 12 volts.



The voltmeter on the instrument cluster reads well below the 14 volts I normally see after the grids stop cycling.



I am afraid I fried something at the alternator.



As I understand it, the PCM controls voltage output and the Dealer would have to read the codes to see what is truly happening with the charging circuit.



I am stuck in my driveway and have only driven about 2 miles with this discharge condition. If I go any farther, I am afraid I will run out of juice before I get to the Dealership (about 5 miles away).



Any thoughts or inspirations? Am I stuck with going to the dealer? I suppose I could take the alternator off and take it down to the auto place and have them test it... but if the voltage is contolled by the PCM, possibly that might not solve anything?



I checked all the connections and they are good and clean. Is there a fuse in the PDC for alternator output? I see a 40 amp fuse in there but it is hard to see if it is blown or not... is there a special way to remove those PDC fuses that I am unaware of?



Thanks in advance...



MacGreenie

 

[Mad Bomber]

Alt ??

I have done that myself I fried the 140 amp fuse in PDC. It was had to see but with a meter you can tell. I belive the 140amp fuse is purple

 

[bmoeller]

Check the alternator fuse in the PDC. I blew mine doing the same thing. It's the one that is held on eith 2 screws.

 

[MacGreenie]

Thanks, folks, it was indeed the PDC 140 Amp alternator fuse!



Just need to get a new one next week.



Reserve me a room at the Arizona Home for the Electrically Retarded. I should know to disconnected the blasted battery before monkeying around under the hood.



Thanks, problem solved!



MacGreenie

 

[Mad Bomber]

Fuse

When I blew mine out I went to Napa and got the biggest one they had I belive it was a 100 amp and ran with that till I could get one from the dealer. BTW that fuse should be in the 6. 00 range not the 20. 00 as the retail.

 

[Mad Bomber]

Originally posted by MacGreenie

Thanks, folks, it was indeed the PDC 140 Amp alternator fuse!



Just need to get a new one next week.



Reserve me a room at the Arizona Home for the Electrically Retarded. I should know to disconnected the blasted battery before monkeying around under the hood.



Thanks, problem solved!



MacGreenie

Hey wait just a minute I resemble that remark that's how I knew what it was. It happened to me when I was installing my ATS manifold.

 

[MacGreenie]

100 Amp Fuse Fixed it!

Got one from NAPA this morning.



Batteries charging just as advertised.



Thanks for the help..... wish I wasn't such a clumsy mechanic.



TDR... . best investment I ever made!



MacGreenie