charging system issue...what am i missing?

[TSI_shinobi]

So I Had a Charging system problem, the wires that bolt to the back of the alternator pulled out of the eyelet. so I pulled the alternator, and Soldered a new eylet on the wires (big copper one) and warrantied my alternator since i already had it out (I tested the new one on a computerized bench and it changed at 14.6V)... new alternator is in and everything is plugged up, but its only charging at 12v (maybe less)its slowly drainging the battery....

so what am i missing?

the resistor that is in the relay center? whats the voltage at the resistor supposed to be?

 

[ktmrider]

Those wires(s) goto the Field Coil and provide 12v to "energize" the VR and permit charging.

The 100A fuse on that circuit ( by the large box on the battery positive terminal ) likely shorted when the wires pulled out or when you soldered the new eyelet on. Side note, that fuse is bolted into the block, not a slip fit.

There should be 12v at all times on that lead you repaired, easy to check with a DVM or visual on the fuse.

 

[TSI_shinobi]

It doesnt look like the 100AMP fuse is blown... so im still at a loss...

im still goofin on it...

 

[TSI_shinobi]

ok so after looking at it some more...

there is 12.4v at the "S" terminal of the altternator connector. with the key on.
I have very little resistance between the positive terminal, and the B terminal of the alternator.. So i know that wire is good... so i am still missing something...

 

[Lofty]

I would open the 3 or 4 main fusible link block by popping the plastic sides off, putting a voltmeter on the metal where it bolts up, and see if that part of the block is seeing 14v.
(With the car running of course, with key on you obviously will only see 12v from the battery)

If it's not, I would redo your wiring.

If it's not that I would see what the other size of the main altnernator fuse is seeing with the car running.

It IS possible to partially blow a fuse like that, I've had it happen, it didn't appear blown, but it had melted a LITTLE bit leaving not much of the fuse material there and caused me some wiring gremlins.

If that doesn't fix it, you probably got a new/junk alternator.


You have to work in a linear fashion with wiring.

Best of luck!
--Scott

 

[TSI_shinobi]

SO i figured it out finally.

after checking and re-checking, i kept coming back to the alternator being the problem, but I tested it on the tester at work and it came out fine. took it off and re-tested it... it was toast, got a new one... put it on, everything is ok now!

thanks for the help!

 

[rdomeck]

Must have been an Autozone alternator.......