More Charging System Woes

[GP1138]

I've got a good alternator and battery. The battery died on me this weekend coming back from a 90 mile trip. Nothing left on. Today I got home from work and took a look with my DMM.

 

My alt is putting out a good 14v. Because I've run a seperate charge wire from the alternator to the positive post, I can check the alternator output independent of the charging system, and when I disconnect it the alt puts out full power. However, when I reconnect it to the system via the positive post or the battery positive terminal, it then stops and the DMM just reads battery voltage. WTF???? Bad ground? Fuse? ?????

[GTP091]

You should test the output of the alternator with an ammeter. The voltage regulator can cause the alternator to appear to have good voltage when in reality it's barely putting out any amps. I've seen this quite a few times with other cars; and had the alt only giving out 2A which isn't even enough to run the radio. Otherwise you could try cleaning all connections with a wire brush and alcohol wipes; just coat them with dielectric grease after reassembly to keep out moisture and corrosion. Hopefully the battery wasn't bone dead they're never the same after a complete discharge.

[slick]

http://www.econofix.com/alt.html

[GP1138]

When I started the car this morning, going out to start trying to diag some more, it appeared to start charging again. However, it then stopped after about a minute.

 

I also discovered a DEI security system alarm wired in, with fuses pulled and the control box removed, it was in the center console. It doesn't appear to have any relation to this problem, but I figured it's worth a mention.

[GP1138]

When I started the car this morning, going out to start trying to diag some more, it appeared to start charging again. However, it then stopped after about a minute.

 

I also discovered a DEI security system alarm wired in, with fuses pulled and the control box removed, it was in the center console. It doesn't appear to have any relation to this problem, but I figured it's worth a mention.

[slick]

Keep in mind, those are wired PARALLEL to the oem wiring. They only wire that is ever cut is the starter wire (if the equipment has starter disable and is an alarm). But even then, most installers will not cut the starter wire. Too much liability issues to deal with.

[GP1138]

Just to have this down completed, fixed with the following:

 

New threaded side posts.

Original charge wire (since I determined that wasn't what was killing the volt regulators)

And with BXX and Ken's help we bypassed the ECM and just wired the L-terminal directly to the Instrument Cluster idiot light as it was in '95.

 

Now pulling 13.6-14.2 at idle. THANKS EVERYONE IN DAYTON WHO HELPED!!!!!!

[Addicted to eaton]

thats good to hear. Lets home it last this time right?

[GP1138]

FFFFFFFFFUUUUUUUUUUUUUUU

 

http://dl.dropbox.com/u/11510888/IMG_1153.MOV

 

I've purchased a battery-to-engine ground strap to see if this might be the issue. I can't imagine what else it could be other than bad wiring in the engine harness somewhere.

Edited September 19, 2010 by GP1138

[White93z34]

its doing this shit again?

[GP1138]

It'll charge when sitting still. But when I start ROLLING at all it'll go down to batt voltage. I'm stumped.

[GP1138]

Replaced negative cable; ran it to where I ran the chassis ground on the transmission (is this a bad place?) - NO GO. Still no charge while rolling. I'm utterly lost here.

[ruktosk]

Is your belt tight and in good condition? There isn't a lot of play in it is there? If it charges at idle, but not under load it sounds like the belt might be slipping on the alt pulley.

[Highmilagecutlass]

Is your belt tight and in good condition? There isn't a lot of play in it is there? If it charges at idle, but not under load it sounds like the belt might be slipping on the alt pulley.

I agree with Ruktosk , it sounds like the belt is slipping but that would effect your power steering pump and water pump as well.

[GP1138]

I replaced the belt yesterday. No go.

[AL]

hows the belt tension?

[Garrett Powered]

Replaced negative cable; ran it to where I ran the chassis ground on the transmission (is this a bad place?) - NO GO. Still no charge while rolling. I'm utterly lost here.

 

 

that is correct however the block to the battery tray carries the main grounding signals.

[Garrett Powered]

is your exciter wire exciting the alt to charge correctly? a good alternator/battery garage could diagnose and fix this problem in no time.

[GP1138]

Of course now that I say anything I take it on a good jaunt and beat the shit out of it and it's solid 14v the whole way. This fucking car...

[alec_b]

Have you checked the thermistor for the battery? It's on an orange wire I believe near the battery (it's been a while since I had my aurora). I'm assuming we're talking about the aurora?

[ManicMechanic]

1996 cutlass 3.4

[GP1138]

is your exciter wire exciting the alt to charge correctly? a good alternator/battery garage could diagnose and fix this problem in no time.

 

So, the current wire wrapped around the CV shaft, forcing me to replace it. Bundled it properly back so it won't do that again, and now it's charging at a constant 14v with lights, heater, radio, etc running.